Clinical practice guidelines on the environment and mental well-being

INTRODUCTION

Our environment, both natural and built, plays a crucial role in our health and well-being. The literature suggests that natural and built environments affect (either positively or negatively) the well-being, quality of life (QoL), and psychological health, such as depression, anxiety, stress tolerance, and sleep [Tables 1 and 2].[1,2,3,4,5] The effect is not limited to the general population, but persons with mental illnesses (PWMIs), such as anxiety, depression, schizophrenia, dementia, and autism, also benefit substantially from the favorable environment.[4,6,7] A good amount of literature has established the positive influence of the natural environment (green space, biodiversity, land mixes, waterscapes) on the well-being and mental health of individuals.[1,8,9,10] Similarly, the impact of the built environment and neighborhood characteristics (such as urban design, building infrastructure, social spaces, transport system, parks, recreational centers, etc.) on the well-being and psychological aspects of the community dwellers has been systematically researched with positive results.[11,12,13] Notably, the beneficial effect of the conducive natural and built environments not only is restricted to the community or neighborhood but also extends to health facilities, for example, nursing homes, residential care facilities, and emergency departments of hospitals.[14,15,16] Apart from the direct and indirect effects of the environment on the mental well-being of the individuals, several mediating and moderating factors, for example, age, socio-economic status (SES), severity of the psychiatric conditions, availability of social welfare services, gene–environment interaction, and family/social support, influence the impact of the built environment on the health and well-being of people.

Table 1.

Environment and well-being

Type of Environment
Natural	Ecology Biodiversity (abundance, species richness) Greenspaces (forest, park) Waterscapes (river, riparian, ponds) Landscapes, field Quality of air Pollution: noise, light
Built environment	Urban design (e.g.,, smart cities) Building infrastructure Habitation: communities, slums, urban colonies, streets, overcrowding Roads and transportation, electricity, sanitation Hospital building and nursing home Office spaces Schools Public services (social services, shopping complex, food outlets)

Table 2.

Environment affecting various well-being and psychological parameters

Well-being and Psychological Variables Influenced by Environmental Characteristics
Well-being	General well-being Happiness Physical health Psychological well-being Quality of Life (QoL) Cognitive function Resilience
Psychological Health	Common mental health conditions: depression, anxiety, stress Severe mental health conditions: schizophrenia Child and adolescents: autism, attention deficit hyperkinetic disorder, intellectual disability Geriatric population: dementia Others: psychological trauma, distress

Various models or frameworks have been posited to explain how our built and natural environments influence our well-being and mental health. One widely researched and utilized model is Bronfenbrenner's bioecological model of human development, which posits that human development is a product of interaction between the growing human organism and its environment.[17] Various urban designs and natural habitat-related models based on this model have studied how different promotive and protective factors and processes (PPFPs) related to the environment promote the resilience and well-being of an individual.[5,10,11]

Various validated measuring tools have been developed to study the impact of the built environment on the psychological health and well-being of the people. Such instruments evaluate housing characteristics (plot size, the rise of the building, etc.), neighborhood features (parks, community centers, green spaces, social spaces, etc.), and their relative distribution on people's health and psychological well-being. However, such instruments are not available in low- and middle-income (LAMI) countries, including India, which limits research on urban health in these nations. Another crucial limitation is the current level of evidence of the built and natural environments and the relationship with the health and well-being of individuals; although several systematic reviews, including a few metanalyses, are available on this topic. However, the research is quite heterogeneous with various methodological flaws (lack of an adequate sample size, psychometrically sound measures, long-term effectiveness data, etc.). Furthermore, most research is that of observational, cross-sectional, or (a few) longitudinal designs, while experimental research is still less. Although governmental and independent agencies' guidelines/recommendations are existing on various aspects of urban design, environment conservation, and ideal health facilities,[18,19,20,21] their positive effect on the well-being and psychological health has not been systematically documented in the Indian literature. Moreover, no clinical practice guidelines prevail, particularly those looking at the mental health and well-being aspect of urban design and environments.

Given the scarce literature on this topic and the absence of any practice guidelines from India, our country's progression of environments and mental health is tardy. The current clinical practice guidelines (CPGs) attempt to bridge this existing gap in the literature from India. In these guidelines, we provide various socio-ecological frameworks that explain the mechanism behind the effect of the built and natural environments on the well-being and mental health of the people, various moderating and mediating factors for this association/causation, research on the relationship between environment and different mental health parameters, including mental disorders, special mention of the vulnerable population and urban environment, including their current level of evidence, different instruments used to study this topic, and in the end make some recommendations as to how built and natural environments can be utilized/modified for promoting and benefitting the mental health and well-being of the community members. These guidelines can guide policymakers, urban designers, researchers, hospital administrators, and clinicians to incorporate this science into their daily disposition and ensure that the environment's inherent impact can be tapped and utilized for the benefit of the population and persons with psychological issues.

Theories or models of the socio-ecological factors affecting the well-being/mental health: Various theories or conceptual frameworks/models have been proposed to explain the mechanism or dynamics of the environment with well-being and mental health [Table 3]. They have in common that individual factors interact with the broader national or global trends and local (social) and environmental (natural or built environment) factors to bring about a change (positive or negative) in the well-being and psychological health of the community members. The above factors act by either improving the people's resilience (to mitigate or fight against various internal and external stressors of life) or providing a conducive environment to thrive and grow.

Table 3.

Theories/models of the socio-ecological factors affecting mental health or well-being

Theory/models	Key features
Socio-ecological model Bronfenbrenner’s bioecological model[17]	Four key aspects of nature and their interaction with an individual determine the impact of nature on well-being or mental health. Natural features (size, type, quality) Level of exposure to nature (proximity and time spent with nature) Experience (interaction with nature, dose) and Effect (mental health and psychological well-being)
Model of psychological and mental health resilience[1]	The model posits that individuals living in favorable environments have higher psychological health resilience and a shorter response time Exposure: natural environment Mechanism of positive mental health: ✓ Mitigation (e.g.,, reduced urban heat island) ✓ Instorative (e.g.,, physical activity and state of nature connectedness) ✓ Restorative (reduced anxiety/attentional fatigue) Design principle (to promote mental well-being): ✓ Accessibility (increased frequency of use) ✓ Versatility (increased chance of contact with nature, e.g.,, waterscapes) ✓ Habitat (quality, e.g.,, water quality) and biodiversity
Conceptual model of urban health[11]	The factors that determine health and non-health outcomes are Enduring structures: economic systems, government, culture Column 1: Major national and international trends [immigration, sub-urbanization, changing roles of the governments (demonetization)] Column 2: Municipal level determinants; Government, policies, and practices of all levels; Markets: food, housing, other goods; civil societies [community capacity, community movements (unemployment, laws)] Potential role of public health intervention and research Urban characteristics (demographics, Socio-economic status, built environment, health and social services)
System model for resilience[5]	Multiple interacting systems determine human resilience Promotive and protective factors and processes (PPFPs) at different scales gathered as a single multi-level system Individual level-biological systems (immune system, stress response system, and biological vulnerabilities) and psychological systems (cognitive reappraisals, secure attachment, distress tolerance, etc.) Social level factors (family cohesion and support, parental involvement and parenting, household income, etc.) Built environment Natural environment

Most of these models stem from Bronfenbrenner's bioecological model of human development, which posits that human development is a product of interaction between the growing human organism and its environment. This environment involves various systems, such as individual systems (biological-immune system, physiological stress responses, and psychological-cognitive processes, coping styles), social systems (family cohesion and support, parental involvement and parenting styles, household income, etc.), built environments (urban design, neighborhood characteristics, community resources, etc.), and natural environments (landscapes, green spaces, waterscapes, and biodiversity), which serve as PPFPs to influence the resilience and well-being of an individual.[5]

A few models are primarily geared toward the natural environment/habitat in which an individual lives and experiences various aspects of life. The socio-ecological model considers four key factors to determine the (positive) effect of nature on the community members: 1) natural features, such as size, type (green spaces, waterscapes, etc.), and quality of the natural environment (quality of the water, air, trees, noise-free areas, soothing sounds, etc.); 2) level of exposure to the natural environment, which is determined by the proximity of the natural resources to the community dwellers and time spent with the nature (walk, viewing, social interaction, recreational activities, etc.); 3) experience/interaction with the nature, for example, how an individual perceives the available nature around him (its quality, abundance, biodiversity, utility) and interacts with it (self-connection, transcendence); and 4) the effect of the nature on the well-being, including psychological well-being, and health of an individual (reduction in stress, warding off cognitive fatigue, improved self-concept, etc.).[1]

Another model that focuses on the natural environment, particularly concerning waterscapes, is the psychological and mental health resilience model by Zhang et al.[10] This model hypothesizes that waterscapes can promote the well-being and mental health of an individual through their mitigating effect (e.g., reducing urban heat island), instorative capacity (e.g., promoting the physical activity and state of nature connectedness), and restorative effect (reduction in stress, anxiety, and overcoming attentional fatigue). This model is developed from the following three theories: 1) the attention restoration theory, which suggests that a restorative environment can alleviate mental fatigue caused by extensive episodes of concentration and focus (known as directed attention). Being away from the attention fatigue causing stimuli and involuntary attention (also known as fascination) toward the natural environment provides an opportunity for reflection; also, the extent to which (restorative) an environment is enriching and engaging and compatible with one's intensions or inclinations plays a mechanistic role in restoration of mental fatigue.[22] (2) The psycho-physiological stress recovery theory (PSRT) states following a stressor/series of stressors, exposure to a natural environment (vs urban environment) has restorative influences involving a shift toward a more positively toned affective state and favorable changes in the physiological parameters and is associated with a greater sustained attention. These positive changes are due to a greater parasympathetic drive triggered by the exposure to a natural environment;[23] (3) the biophilia hypothesis: Humans have preferred natural environments and have an inherent emotional connection to other organisms that can have significant positive psycho-physiological reaction in the human body.[24,25]

The psychological and mental health resilience model proposes that the positive impact of the waterscapes, or natural environment, on the well-being and psychological health of an individual can be ensured by harnessing the benefit of the design principle; the latter incorporates accessibility of the natural environment (increased frequency of use), versatility (increase the chance of contact with nature, and habitat (quality, e.g., water quality), and biodiversity.

Another popular model in urban design and health/well-being is the conceptual model of urban health.[11] It postulates that the enduring structure of a country, such as its economic system, government functioning, and culture, is a continuous factor affecting the health and well-being of the community members. These macro-level factors interact with major national and international trends (such as immigration, war, economic recession, pandemic, demonetization, etc.), municipal level determinants (Government policies, markets, housing, availability of the quality goods, civil society structure and functioning, etc.), and urban characteristics (demographics, SES, built environment, health and social-welfare services) to bring about a change (positive or negative) on the well-being and mental health of individuals.

Factors moderating and mediating the effect of environment on well-being/mental health: Research shows that it is not only the environment (natural or built) that affects the well-being and mental health of the people, but several mediating and moderating factors influence (positively or negatively) the impact of the environment on the health and wellness of the community dwellers [Table 4].[26,27,28,29,30] These factors could be personal and/or environmental. For instance, age is a critical variable that affects the neighborhood's mental health benefits, with the green spaces being greater and significant in physically active elderlies than young adults.[1] Similarly, the severity of the mental health conditions also mediates the impact of the environment on the well-being or mental health variables of the people, with green spaces and supportive physical environments (e.g., architectural designs, tailored individual adaptations) having a more pronounced (positive) influence on the mental well-being/activities of daily living of mild-moderately depressed and demented individuals, respectively, compared to severely ill individuals.[27,28] Likewise, the positive impact of the relocation of the socially disadvantaged population to a better or resource-rich neighborhood is mediated by the characteristics of the surrounding neighborhood of the relocated neighborhood. The moving to opportunity (MTO) experiment involving low-income families, with a 10–15 years follow-up design, shows that if the surrounding environment of the resource-rich relocated neighborhood is conducive and non-discriminatory, it has greater and significant positive mental health benefits vis-a-vis a hostile or unfavorable surrounding neighborhood.[29]

Table 4.

Moderating/mediating factors influencing environments and mental health and well-being

Moderating and mediating factors	Mental health conditions/well-being
Personal factors
✓ Age of the individual	Mental health benefits of neighborhood green space are stronger among physically active adults in middle-to-older age (vs younger adults)
✓ Social disadvantages	Socially deprived populations positively get influenced by neighborhood green spaces and conductive neighborhoods around the relocated better place vs affluent population
✓ Severity of mental health conditions (depression, dementia)[27,28]	Green spaces have a more positive influence on the mental status of mild-moderately depressed individuals (vs severely depressed) Supportive physical environment (architectural designs, tailored individual adaptations) has a positive influence on ADL among individuals with mild-moderate dementia (vs severe dementia)
Environmental factors:
✓ Quality of neighborhood[2,13]	Impacts psychological well-being by affecting resilience
✓ Family and broad environment	Mediate impact of physical activities on mental well-being
✓ Perceived biodiversity	Mediate actual biodiversity’s impact on human health
✓ Gene–environment interaction	Variance in depressive symptoms is related to additive genetic increases as a function of social deprivation
Availability of social services	Mediates the impact of built environments and green space on mental health and well-being

Various environmental mediating factors influence the effect of the built environment or nature on the psychological well-being and health of the people. The literature suggests that the perceived biodiversity (vs actual biodiversity or species richness) of an urban built environment or natural environment has a greater bearing on the perceived positive impact of the environment than actual biodiversity. The psychological effect of nature on the affective state of urban dwellers is also moderated by the type of interaction with nature and the form of sensory inputs (e.g., visual, olfactory, auditory, or tactile).[1]

Likewise, it has been found that gene–environment interactions rather than only environmental factors or genetic factors determine the depressive symptoms in the socially deprived situation, and those genetically vulnerable to depression tend to experience more negative effects of the socially deprived environment than those without genetic risk of depression. Such interaction (s) also predispose an individual to remain in the socially deprived location or not move to a better neighborhood, given an opportunity to do so.[30]

Research involving vulnerable populations (elderlies and girl children and adolescents) has also shown how various mediating factors influence the relationship between the built environment and mental health. For instance, a systematic review by reported that it is not only the level of physical activity that determines its positive impact on mental health but also the family structure/dynamics and the broad environment, acting as the mediating factors, that determine such association. McCormack et al.,[13] in their comprehensive review, have reported that elderly-friendly social welfare services mediate the positive effect of the green spaces (conducive built environment) on the mental health and well-being of the geriatric population.

Therefore, researchers and urban planners/policymakers must consider these personal and environmental factors while designing the built environment or regeneration programs to promote the well-being of the community members.

Characteristics of urban design and built environments and the effect on well-being and mental health

Green spaces: Urban green space is linked to people's psychological well-being and positive mental health. The literature suggests that individuals exposed to green spaces have improved affective, cognitive, and physiological health compared to those not exposed to these environments.[1] Furthermore, the positive effect of green exposure is more pronounced in the urban poor (or socially advantaged population) versus the urban rich.[1] The impact of green spaces on the psychological health of people is both direct (visual stimulation, stress reduction, and restorativeness) and indirect (promoting physical activity, social cohesion, and recreation).[3,8] Moreover, exposure to green spaces and biodiversity reduces the risk factors, such as stress and sleep deprivation, of mental disorders. It must be highlighted that it is not only the quantity of the exposure but also the quality, interaction, and perceived restorativeness potential of nature that play roles in (improving) the well-being and mental health of the community dwellers.[1] However, research reveals that this causal relationship between green spaces and mental health is short-lasting, while long-term effectiveness data are lacking. Nature also has a salutogenic role (i.e., fostering psychological well-being through evidence-based urban planning or design before the former becomes a necessity to treat diseases) in urban health. These findings underscore the need to account for the mental health aspect of the environment while making urban plans and considering the mental health aspect of the environment as a crucial public health issue. Integrating this knowledge is particularly vital when planning urban redevelopment in socially disadvantaged areas.[3] It must be highlighted that the current body of evidence is mainly observational, cross-sectional, or longitudinal, while randomized controlled studies are largely lacking.

Waterscapes: Waterscapes or blue spaces (e.g., marine spaces, riparian, water biodiversity) have significant benefits on the well-being and mental health of the people.[1,10] Notably, the positive impact of the waterscapes is greater than that of green spaces. The former improves mental health by warding off the negative emotional states through reducing the urban heat (mitigating effect), providing opportunities for physical activities, interaction with people, a sense of connectedness with nature (instoration), and reducing anxiety and attentional fatigue posed by daily demands of city life or fast pace lives.

In the seminal work by Zhang et al.[10] on the role of waterscapes in promoting psychological health in the population, the authors report that waterscapes have healing effects by increasing the psychological resilience of an individual. Furthermore, blue spaces have an inherent positive impact on the people's psyche, including the people's natural connection with the aquatic life-biophilia hypothesis. Accordingly, to maximize the impact (positive influence) of the bluescapes on the health and well-being of the community dwellers, the urban designer or environmentalist should push for greater waterscape accessibility (e.g., reducing the high-fence walls, creating water-friendly platforms, creating alleyways), increasing interactivity (providing spaces for people to relax, including viewing animals), and restoring water quality (bioremediation and physical remediation). However, more research is required to investigate the mechanistic role of waterscapes in bringing about positive mental health and also how various characteristics of waterscapes, such as the freshness, luminescence, rippling or fluidity, cultural value, and dose–response relationship, if any, determine the impact on health and well-being.

Built environment and urban environment: A large body of literature provides evidence for the relationship of the built or urban environment with the psychological well-being of the population.[3,4,11,12,13,31,32]

The built environment can directly or indirectly affect individuals' well-being and mental health parameters. The direct effect includes the influence of pollutants (air, water, and noise), toxins (lead, solvents), and contaminants (food quality) on the behavior, for example, aggression, and self-regulatory behavior, of an individual. In contrast, the indirect effect pertains to the effect of the built environment on the psycho-social processes, level of control over the environment, social relationships, perceived safety, and restorative capacity [Table 5]. Researchers have posited three theories on how urbanicity can influence the mental health of people: 1) urban penalty model, which states that people living in the urban environment are at a high risk of various health problems due to inherent ill effects of the city life on the individuals, 2) urban sprawl phenomenon, which emphasizes that spread of the urban culture or environmental changes in suburbs negatively affect the mental health of the suburban or rural population, and 3) urban benefit, which incorporates the positive impact of urban life on the mental health of the community dwellers due to greater opportunities and availability of services.[11]

Table 5.

Characteristics of various urban design and built environments that have a positive impact on well-being and mental health

Enviornmental factors/Setting	Characteristic
Natural
Ecology	Quality of green and blue spaces (aquatic and marine environment, biodiversity (abundance), nature’s size, composition, spatial configuration, interaction with nature and human dwelling, lack of noise, quality of air, light, etc.
Greenspace	Quality of green space, street trees, density of trees, spatial configuration of green space, tree canopy density, vegetation structure
Waterscape	Quality of water spaces (river, lakes, riparian); access to waterscapes, space around it for walks, recreation, and sports; diversity of aquatic creatures, flora, and fauna
Landscape	Psychological-friendly landscape (for elderlies, etc.); quality of land, spatial configuration of landscapes, land usage (arrangement of destinations, mix of uses, distribution of parks and recreational opportunities); land use mix with parks, water spaces
Miscellaneous	Quality of air, light, soothing sound, noise-free environment, etc.
Built environment
Urban design/Built environment	Low-rise buildings, renewable and sustainable energy, proximity to roadways, transport system, park, walkability, proper ventilation, recreational opportunities, safety
Neighborhood (community, street, crowd, household)	Residential welfare services, (lack of) overcrowding, housing conditions, rainwater drainage, electricity social capital, sanitation, culture
Hospital/nursing home architecture and infrastructure	Dementia/elderly population: unit size, spatial layout (L-, H-, or square-shaped units), homelike character, sensory stimulation, and environmental characteristics (familiarity, engaging environments, range of private/communal spaces; temperature, noise, lighting); staff behavior; smaller-sized dining rooms, outdoor area (park, walking area, group activities, etc.); washroom (privacy, end/side entry bathtub). Children with special needs, e.g.,, autism: sensory quality (low arousal environment, minimal background noise, soundproof rooms, good ventilation/avoid the intense smell, transition areas between spaces/activities; clear and simple spatial layout). Intelligibility (visual relationship between environments, predictable environments and routine, appropriate proportion of spaces). Orientation (visual support through images, layouts; way findings through maps/color codes) A welcoming, inspiring, supportive, favorably located hospital, with conducive spatial configuration, contact with nature, and respectful toward patient rights, and close to the community positively impacts the mental health and general well-being of patients.
School	Proper light, sitting spaces, washroom, playground, sports period, team activities, physical activities, integrating physical activities at school with the community recreational activities
Public services	Social welfare services (particularly for the vulnerable population, e.g.,, elderlies), health and cultural services, transportation, food outlets, shopping complex nearby, quality of food products
Hospital and emergency services	Trauma-informed care in the emergency department Routine and universal screening for all traumatic experiences (for not only the patients but also health workers), peer support, safety, trustworthiness and transparency, peer support (allowing for an environment of supportive engagement), collaboration and mutuality, empowerment of voice and choice, cultural, historical, and gender issues; avoiding long-waiting time in registration and psychiatry consultation; separate Emergency Psychiatric Assessment, Treatment and Healing units; properly starting the encounter, patient interview and closing the visit (including referral to routine out-patient services)

A systematic review by Evans[31] reports that high-rise building, poor-quality housing, and overcrowding are inimical to the psychological well-being of the residents of the urban region. A built environment, through its physical infrastructure, also impacts the community dwellers' social interactions and social capital. Some of the critical built environments that affect people's mental health and well-being are proximity to roadways, esthetic quality, walkability, urbanicity, access to services, land-use mix, population density, electricity and water quality, and level of crowding. Moreover, subjective experiences of the community members regarding the level of social support, safety, controllability over the neighborhood, and stress process also have a bearing on the psychological health of people. As highlighted previously, perceived social services and tangible support from the government and authorities also influence the psychological health of the community dwellers.

Only a few controlled studies, including from India, have looked into the effect of the built environment-based intervention; for instance, the slum-network program, an integrated housing infrastructure redevelopment program along with the provisions of transport, quality water, electricity, and sanitation, reports the positive effect of such interventions on the QoL of the slum dwellers. However, the positive impact could be sustained only up to 3 months, with a 6-month evaluation revealing a non-significant difference between groups.[33]

Similarly, a study from Hyderabad by Saraswat et al.[34] found that socio-economic vulnerabilities (poor housing condition, lack of access/availabilities of routine facilities, and neighborhood characteristics) are related to self-efficacy and mental health outcomes (anxiety, stress, etc.), and those having higher socio-economic vulnerabilities (vs those having lesser socio-economic vulnerabilities) perceive less control over the situation and lack of available resources during natural disaster, such as flood.[34]

Another pivotal multi-centric study from India, funded by the Indian Council of Medical Research on urban mental health service systems, observed that despite the substantial burden of mental health problems in metropolitan regions, the distribution of mental health services is inequitable in participatory metropolitical cities (Delhi and Chennai) and another major city (Lucknow) of the country. Moreover, the structure and function of district mental health programs in urban areas must be tailored to the needs of people of the urban locality rather than simply trying to replicate the service structure and model of the primary health centers located in the rural region. The study further found that lack of transport facilities, including last-mile connectivity, and financial constraints in reaching the mental health facilities are crucial barriers to accessing mental health services in urban areas.[35]

Concerning a quantitative analysis, a meta-analysis reported that composite SES of the neighborhood is negatively associated with the depression and pooled mental health of the participants. Furthermore, neighborhood urbanicity is positively associated with the above psychological parameters. Strikingly, a null association was found between the natural environment and the mental health of the participants. However, the authors emphasized that the current level of evidence was limited by the lack of robust methodologies across the studies, that is, lack of longitudinal and comparative studies, non-availability of validated measuring instruments, and scarce literature from the low- and middle-income countries.

It must be highlighted that more research is required on this topic, particularly those evaluating the influence of the built environment through a randomized controlled design and long-term longitudinal design and elucidating the mechanism behind these benefits.

Noise and mental health issues in urban regions: Noise denotes an audible acoustic phenomenon (unwanted sounds or set of sounds) that adversely affects people by either directly causing health hazards (aggression, anxiety, cardo-vascular problems) or increasing the risk factors for health issues (sleep disturbances, annoyance, stress, poor cognitive function, etc.).[36] In urban settings, road transport, railways, aircraft, industries, and construction works are common sources of noise pollution, which can lead to several mental health issues. Noise can lead to sleep disturbances: increased sleep latency, fragmented sleep, early awakening, and the inability to fall asleep again. Such sleep disturbances can cause several mental health problems and cognitive dysfunctions among people. The problem is more marked in shift workers, where noise can significantly affect the well-being and QoL of workers.[37] Research shows that annoyance due to aircraft noise and noise sensitivity are associated with psychological ill health, with annoyance falling on a gradient, mediating psychological issues of the population [not at all annoyance has an odds ratio (OR) for poor psychological health 1.7 (1, 3.0), while extreme annoyance has an OR of 4.0 (1.6, 9.5)].

Furthermore, noise can result in increased levels of stress hormones and higher sympathetic tone manifested as an increased heart rate and blood pressure. Therefore, providing an adequate environment with a noise-free zone or optimum sound is vital for maintaining good physical and psychological health.[38] Increased exposure to noise has also been linked to psychiatric hospitalization and increased purchase of hypnotics. It cannot be over-emphasized that mental health facilities, particularly those catering to children with autism and dementia, have an optimum sound level and infrastructure that mitigate excess noise.[36]

Hospital-related parameter: Research shows that hospital-built environments and characteristics of the residential facilities for patients (whether with physical or mental illness) significantly affect the well-being and psychological health of the patients, their caregivers, and also the healthcare providers [Table 5]. Evidence shows that the safety and security, competency, and personalization and choice (SCP) model of a mental health institution's architecture can facilitate or impede mental health conditions and psychological well-being. A more facilitatory model/design [safe and secure environment (vs unsafe and insecure), design that promotes residents' competence (vs dependency), and personalized care or choices (vs absence of such care system)] would promote greater agency, reduced stigma, social interaction, and integration. In contrast, a restrictive or surveillance-led design would adversely affect their well-being, particularly in rehabilitation institutions.[14]

Similarly, the quality of emergency services for trauma victims (physical, psychological, or both) can significantly influence the well-being and psychological health of the patients, caregivers, and health professionals. Trauma can be due to past experiences (historical trauma), medical trauma (due to medical or surgical procedures), or re-traumatization (due to traumatic experiences at the emergency department or hospital premises). As mentioned above, not only patients/caregivers can experience such traumas during the clinical encounter but also the hospital staff or service providers. Therefore, the researchers have proposed trauma-informed care (TIC), an organizational structure and treatment framework that involves understanding, recognizing, and responding to the effects of all types of traumas.[15] It involves patients' and care providers' physical, psychological, and emotional safety. The critical aspects of such a care framework are routine and universal screening for traumatic experiences of all the stakeholders, trustworthiness, peer support (collaborative care and providing a menu of options), and dealing with cultural, historical, and gender issues of the patients. TIC also entails properly initiating patient encounters, implementing key characteristics of TIC in patients' interviews, and closing the interview with the patients, including admitting them promptly or their disposition. Specifically, for psychiatric patients, emergency department visitors (ED) with psychological issues must not be discriminated against; they should not face a long waiting period and be promptly seen/referred to a psychiatrist. Last, an Emergency Psychiatric Assessment, Treatment, and Healing unit should be established to ensure visitors' privacy, prevent overcrowding, and provide a soothing and safe environment.[39]

For health professionals, including mental health professionals, it is crucial that patients visiting health facilities or visitors of ED with a history of trauma, physical or psychological, be prevented from re-traumatization (vicarious trauma) through trauma-informed care.

Psychiatry in-patient setting and mental hospitals

The built environment and inter-personal dynamics in psychiatry in-patient are critical as usually patients have a longer hospitalization during a greater radius of movements in the facility (vs physically ill patients); the recovery is aimed at improving everyday functioning within the facility and outside, and patients, due to their psychopathologies (perceptual disturbances, altered mood state, thought problems, cognitive dysfunctions, etc.), are vulnerable to environmental influences. Multiple-place theories, which posit that different sub-places in a hospital/setting (patient's room, hospital's external spaces, the overall hospital care unit, wards' external space, etc.) have bearing on the well-being of the patients, and a pro-social hospital environment can have a facilitatory role on the recovery and well-being of in-patient service users.[40] A systematic review involving 52 records (including 26 original studies) suggests that hospital environments, built and human interactions, influence mental health (e.g., anxiety, aggression, confusion), well-being (sense of safety, agency, comfort, etc.), and recovery of the patients (reduced hospital stay, healing effect, etc.) admitted in psychiatry in-patient facilities through environmental stimulation (lights, noise, sensory cues), a sense of environmental control (privacy or socialization, access to facilities, including staff, seclusions, etc.), and symbolism/associations (locked doors, glass rooms, covered nursing station, dull and over-controlling environment, etc.)[41] [Table 6]. Researchers have also suggested some of the best practices in the psychiatry in-patient facilities in terms of ambient features, architecture, interior design, furnishings, familiarity, social features, and so on, which can have therapeutic and rehabilitative roles in the mental health and well-being of patients (detailed in Table 6).[42] A few key characteristics have been described below and are highlighted in Table 6.

Table 6.

In-patient psychiatry facility characteristics and their impact on mental health outcomes

Various domains of in-patient built environments	Preferred Characteristics and evidence
Ambient features	Soft, indirect, and pervasive or full-spectrum lighting Ample natural daylight Good air quality: air quality with fresh air, good ventilation, and neutral odors Highly reverberating places to be avoided Evidence: Depressed patients exposed to sunlight have reduced hospital stay; morning lights compared to evening light have therapeutic for bipolar depressed patients.[45] Adequate sensory stimulation is related to greater perceived reduction in psychiatric symptoms and aggressive behavior.[46] Poor thermal comfort, unpleasant esthetics, and unhygienic conditions are associated with increased absconding, aggression, and discomfort.[47] Abstract art can promote anxiety, glass rooms can lead to overstimulation, and absence of stimulation can give rise to feeling of institutionalization and confusion).
Architectural features	Adequately sized and number of windows promoting access to external environments is favorable Outdoor gardens and access to nature Seclusion rooms near and within sight of nursing stations but outside of main patient corridors and activity areas Availability of staff lounge Space to accommodate new technology in view of rapidly evolving built design and technology Group meeting space Family meeting space off-ward has better patients’ satisfaction and outcome Having a communal space where males and females can communicate and socialize promotes clients’ satisfaction Evidence Family meeting space off-ward is associated with greater clients’ satisfaction and better outcome.[41]
Interior design features	Should account the unit’s symbolic meaning. Demarcated reception area and welcoming gestures toward patients and visitors are beneficial Less-restrictive environments and low-perceived sense of power difference between patients and staff Evidence: Favorable symbolism/associations are associated with lesser absconding, seclusion, emotional distress, self-harm, and aggressive behaviour.[42]
Furnishings	Homely décor’ Evidence: Natural wood veneer on doors, hallway rails, and nursing stations can soften the look of the facility. Upholstered chair and adjustable furniture have positive psychological impacts on the patients.[43]
Familiarity	Familiar tone of the patients’ room Artwork (soothing but not exciting) Images of nature can reduce anxiety
Color	Muted colors are preferred Evidence Brighter colors can alleviate depression but can promote agitation in delirious patients; warm blue colors can be soothing and have sedative effects.[42] Use of colors in units must be in consultation with the hospital authorities and treating team.[43]
Other interior design considerations	Accommodating patients with competing needs, e.g.,, manic, or overstimulated patients vs depressed or withdrawn patients. Natural plants in the unit have positive effects To promote safety, tamper-proof electrical outlets, shatter-proof windows, breakaway curtain rods, stainless-steel mirrors, and lockable water taps are advised. Evidence: Locked ward doors and spatial confinement/seclusion rooms are associated with emotional distress, shame, fear, vulnerability, worsening of psychiatric symptoms, and self-harm and negatively impact recovery.[48,49] Natural art and stress-reducing attributes, e.g.,, natural art, garden, and access to garden have therapeutic roles through their calming effect.[50] Being unclear to various hospital processes and lack of information about the reasoning (e.g.,, privacy, restrictions, spatial configuration) can result in emotional distress, anxiety, and confusion.[51,52]
Social features	Provision of social spaces Small group circular arrangement of furniture promotes socialization. Area prone to overcrowding should be avoided Space for privacy and communal spaces should be provisioned and balanced appropriately. Evidence: Lack of privacy, such as crowding, mixed-gender rooms, excessive environmental stimulation, and absence of alternate space to roam around in the ward are a/w greater distress among the female victims of trauma.[41,53]
Special issues	An open nursing station has positive psychological, behavioral, and social effects. For older people: Brighter lights, high level of illumination familiar images, familiar dining experience, opportunities for exercise or other physical activities, shorter corridors, sufficient visual cues Suicide-proof (enclosed bottom) handrails and grab bars throughout the facility Chairs (and commodes) should have a sufficient height and arm length. Bathrooms be large enough to accommodate wheelchairs and care attendants. Increasing the visibility of toilets can reduce incontinence. Evidence: Psychological distance between staff and patients results in greater psychological distress and aggression in patients; in contrast, greater accessibility and communication between them are related to lesser disruption to staff’s work by patients and less fear among the patients.[47,54]

a/w: Associated with

For instance, research shows that mental health facilities if located in a secluded place, far off from the routine hospital facilities, with poor transport connections, and highly restrictive settings (over-crowding, lack of ventilation, poor-quality washrooms, lack of visitor facilities or social contact), can negatively influence the well-being and psychological health of the residents.[14]

A comprehensive review and research work by Ussher[53] from the University of Durban, South Africa, reports that a building or architecture can affect healing, stress level, and general well-being of patients, including residents; moreover, a well-planned hospital building can prevent the ill effect of the building otherwise would have (if not appropriately planned).[53,54] Researchers emphasize that the spatial configuration of the hospital building, its location, its domestic-like environment, neighborhood characteristics, contact with the outside world, integration with the community, and participatory for the caregivers/friends of patients have a positive influence on the well-being of the patients' availing services in such facilities. Moreover, building design can also affect the mental health stigma, and a secluded or restrictive building and intimidating treatment style can worsen the mental health stigma among the community members. In contrast, a mental health facility integrated with general health care and located closer to community facilities and residential areas will reduce the mental health stigma. Furthermore, a hospital environment that is welcoming and positive, respects patients' rights (dignity, privacy, respect, dignity), has legible wayfinding and available services, is in touch with nature (water spaces, greenery, biodiversity, etc.), and has transition spaces, with a blend of personal and public space that caters to the needs of the patients, facilitates recovery, positive in-patient experience, and early integration in society post discharge.[14,53]

Special population: The built and natural environments have a bearing on the mental health and well-being of the vulnerable population. There is a significant body of research involving geriatric populations and children and adolescent populations that has proven that built environment characteristics and natural environments, through their various critical characteristics and interplay, influence the health of these populations, including those suffering from mental illnesses, such as autism and dementia [Table 6].

For instance, research points out that age-friendly smart cities involving Internet- or digital-driven and supported cities with residential welfare services, ecologically friendly mobility, low-carbon-dioxide emission levels, and public safety nets and access to services significantly improve the well-being and mental health of the general population, more so, geriatric people. However, inequitable distribution of such advanced, technologically laden services, for instance, when it is restricted to certain geographical locations or neighborhoods, may result in perceived discrimination and poor mental health parameters.[32]

In a scoping review, the authors reported that mobility and social participation of geriatric persons are related to proximity to the resources and recreational facilities, which in turn improves their well-being and QoL. In contrast, poor user-friendly walking environments and neighborhood insecurities are related to adverse mental health outcomes among elderlies.[55]

Environment and neighborhood and institutional facilities also have a bearing on the mental health of persons suffering from dementia. A systematic review involving 64 empirical studies and nine reviews found that unit size, spatial layouts, level of sensory stimulation, environmental characteristics (outdoor, dining area, home-décor, social spaces), and the behavior of the staff and service providers of the institutional facility significantly influence the aggression, orientation, and stress among the residents of dementia care facilities. Specifically, a small unit size, L/H-shaped layouts, smooth room colors, homely flooring and furniture, spaces for socialization, privacy in the washroom, the small size of the dining area, the garden outside, and support from the residential staff have a positive impact on the mental health of the persons with dementia.[6] Another review involving 72 studies found that global environments, architecture features, moveable environmental aides, and tailored individual approaches with provision, referred to as the holistic environmental change, can positively influence the mental health of the elderly with dementia.[16] The mechanism behind such positive effects can be conceived as such comprehensive perceived environment changes act as stimulation and reminiscence therapy for individuals suffering from dementia.[56]

Similar to elderlies, the built environment and neighborhood characteristics influence the well-being of children and adolescents. A study by involving seven reviews with adolescent girls and young adults as samples highlighted that the positive impact of physical activity on mental and physical health, including self-concept, self-image, social relationships, and quality of life, is mediated by the neighborhood characteristics (availability of community sporting services, social support), linkage of school with community recreational facilities, and family support. With a supportive family structure, greater opportunities for physical activities and community recreational facilities have more positive mental health benefits.[57] Another study from Dehradun's slum involving young girls found that gender inequality, limited access to education, chauvinistic society, over-crowding, and social deprivation can result in higher anxiety, depression, gender equality attitude, poor coping, and resilience among them. However, interventions (Nai Disha or new pathways) aimed at improving their self-image, communication skills, mental health, communication skills, relationship skills, self-care, and participation as change agents in the community resulted in substantial improvement in scores in all five areas, and some of the improvement persisted for as long as 8 months.[58]

The literature on children and adolescents with autism has shown that the built environment of child-care institutions substantially influences the mental health of children. A review of 21 quasi-experimental and intervention studies found that characteristics of child-care facilities influence the mental health of autistic children, wherein conducive sensory stimulation (low-arousal environments, favorable acoustic stimuli, the optimal smell in the vicinity, small spaces, demarcated transition zones, clear spatial layouts), intelligibility (visual relationship between environments, predictable environments and routine, an appropriate proportion of spaces), and orientation (visual support through images, layouts; wayfinding through maps/color codes) have a positive influence on the affect and behavior of such children.[7]

Likewise, research on children and adolescents with attention deficit/hyperactivity disorders (ADHD) has shown that green outdoor activities as compared to other activities (e.g., indoor activities) during the afterschools and weekends result in significant improvement in ADHD symptoms.[59] This improvement can be explained by the attention-restorative theory of Kaplan as highlighted above.

Therefore, such built-environmental characteristics should be taken into account while designing urban environments as well as care facilities for the vulnerable population, which may facilitate their treatment and rehabilitation.

Another vulnerable population is pregnancy lady and young mothers; research shows that increased exposure to particulate matter ≤2.5 μm in diameter (PM2.5) during pregnancy is significantly associated with increased odds of post-partum depression at 6 months and also for the late-onset PPD.[60] Similarly, pregnant women without past history of psychiatric illness, upon exposure to noise, specifically night-time noise, have a higher odds of hospitalization for depression and other psychiatric conditions later in their lives.[61] A retrospective observational study from New York involving health electronic records of 9000 pregnant women noticed that mixed land use, lower walkability, more retail access (proxy for connectedness of the neighborhood in providing community support to women), and lower PM2.5 concentration (pointing toward semi-urban or less-affluent areas) have greater risk of post-partum depression.[62]

Rural versus urban differences in mental health conditions

Extant literature, including from India, shows that the prevalence and manifestation of mental disorders vary between rural and urban settings, with schizophrenia and depression being commoner in urban areas compared to rural settings; in contrast, alcohol use disorders are more prevalent in rural settings.[63,64,65,66] The common theory/hypothesis behind this difference is reduced social support in an urban environment, unfavorable neighborhood conditions (over-crowding, discrimination, poor access to social support or welfare services, including health and education), higher stress levels, and selective migration. The selective migration refers to persons vulnerable to developing mental health conditions who tend to move to urban locations; moreover, upon developing psychiatric illnesses, they do not relocate to rural areas (vs those without mental health conditions).[65,66] It must, however, be highlighted that these days, the qualification of the rural versus urban setting forms a continuum rather than just a dichotomy.

Assessment tools for studying the relationship of built environments/nature and health parameters

Studying the relationship between the built environment/nature and health parameters is highly dependent on the availability of psychometrically sound instruments for measuring the built environment and nature; in the absence of the latter, the accurate measurement of the built environment or nature is not possible, which, in turn, can impede the research in this topic. Notably, there is a lack of such instruments in India. Hence, we have to either adapt currently available instruments, primarily contextually limited to Western standards, or use geographic information systems or other proxy markers.

Traditionally, two approaches have been used to measure the built environment in the research on the relationship between the environment, built or natural, and mental health or psychological well-being: independent observational measures and Geographic Information System (GIS) [Table 7].[67] While GIS has the advantage of providing a birds-eye view of the current extent and level of the built environment or natural areas (type, spatial distribution, quantity, geographical distribution, relationship with neighborhood areas, etc.) of a wider region, it might not provide a sufficient granular picture of the built environment/natural area. Moreover, not only countries or communities have such resources; therefore, research in these regions may also be impeded if they solely rely on the availability of robust GIS.

Table 7.

Measures used to assess the urban or built environment

Measure	Characteristics
Geographic Information System (GIS)[67]	Commonly used method to measure built environments and natural areas (greenspaces, waterscapes, etc.)
Built Environment Site Survey Checklist (BESSC)[69]	Developed jointly by Royal Free and University College Medical School, the Institute of Psychiatry, and the National Centre for Social Research, in collaboration with the Oxford Centre for Sustainable Development at Oxford Brookes University. Measure physical characteristics of housing. 27 items covering four major areas or housing: ✓ Characteristics of buildings ✓ Space around buildings ✓ Facilities and accessibility ✓ Safety and security Good interrater reliability (k=0:50)
Residential Environment Assessment Tool (REAT 2.0), UK[68]	Redeveloped by National Institute for Health Research, Wales Utilized extensively in housing regeneration programs Have street level and property variables around (1) neighborhood conditions (e.g.,, litter in public space, property maintenance), (2) natural surveillance (e.g.,, clear views of the street, clear views of windows and doors), and (3) natural elements (greenery in public spaces, purposively planted vegetation in front gardens). Has the highest inter-rater reliability
University of Miami Built Environment Coding System (UMBECS)[70]	It has been jointly developed by Royal Free and University College Medical School, the Institute of Psychiatry, and the National Centre for Social Research, in collaboration with the Oxford Centre for Sustainable Development at Oxford Brookes University. Developed as a built environment coding system to measure streetscape block. Physical characteristics of ✓ Built lots in the interior of a block ✓ Built lots at the corners or intersection of two streets ✓ Vacant lots and parks Seven categories of features which can be coded at neighborhood and block level and are ✓ Walkability ✓ Visibility interior (e.g.,, windows) ✓ Visibility exterior (e.g.,, balcony) ✓ Character (balcony embellishment, fence) ✓ Frontage dimensions ✓ Contiguous Diversity (mix of building use/purpose (occupied residential units and building rise) ✓ Density (number of occupied residential units per lot and rise of buildings) Has been validated in studies involving children and adolescents and mental well-being research
Systematic Social Observation (SSO) in the US[71]	Developed by PHDCN in 1995 A standardized approach to directly observing neighborhoods’ physical, social, and economic characteristics, one block at a time Developed to assess built environment characteristics upon young people’s development. Data are typically collected through both videotape and observer logs The domains covered are ✓ Physical disorder (graffiti) ✓ Social disorder (fight/hostility in the neighborhood) ✓ Physical decay (condition of the building) ✓ Commercial building security (properties with pull down metal gates) ✓ Alcohol/tobacco advertising ✓ Bars/liquor stores Widely used in the research

PHDCN: Project on Human Development in Chicago Neighborhoods

Researchers have developed various independent observational measures to study the relationship of the environment with the mental health parameters and health of the population, including vulnerable groups, such as children, adolescents, and the elderly.

The most extensively used tool is the Residential Environment Assessment Tool (REAT 2.0), which has been widely utilized in housing regeneration programs in the United Kingdom (UK). It has street level and property variables around (1) neighborhood conditions (e.g., litter in public space, property maintenance), (2) natural surveillance (e.g., clear views of the street, clear views of windows and doors), and (3) natural elements (greenery in public spaces, purposively planted vegetation in front gardens). REAT 2.0 has the highest inter-rater reliability among the various available tools.[68]

Another commonly used tool is the Built Environment Site Survey Checklist (BESSC). This has been used widely in the housing redevelopment or regeneration program in urban settings. BESSC measures the physical characteristics of housing and comprises 27 items covering four major areas of housing: (1) characteristics of buildings, (2) space around buildings, (3) facilities and accessibility, and (4) safety and security. It has good inter-rater reliability (k = 0:50).[69]

The University of Miami Built Environment Coding System (UMBECS) developed as a built environment coding system to measure streetscape blocks has been widely used in the United States and North America. It has been utilized in research on children and adolescents' neighborhood and mental well-being. It measures the physical characteristics of neighborhood under the following four domains: (1) built lots in the interior of a block, (2) built lots at the corners or intersection of two streets, (3) vacant lots, and (4) parks.[70]

Last, Systematic Social Observation (SSO) is a standardized approach to directly observing neighborhoods' physical, social, and economic characteristics, one block at a time. It was developed to assess built environment characteristics upon young people's development. Data are typically collected through both videotape and observer logs. The domains covered are physical disorder (graffiti), social disorder (fight/hostility in the neighborhood), physical decay (condition of the building), commercial building security (properties with pull-down metal gates), alcohol/tobacco advertising, and bars/liquor stores. It has been widely used in urban health research.[71]

Governmental (or independent agencies') guidelines and recommendations on urban development, health facilities, and well-being of community members/service users

Many national guidelines and recommendations have been developed to ensure that the urban design and natural environment are protected and used in an eco-friendly manner. This would not only safeguard concurrent urban development and well-being of the community dwellers but also ensure sustainable development. The guidelines pertain to natural environments, such as green spaces,[72] water bodies,[19,73] and building development[18] and urban development.[21] An exclusive guideline on Indian health facility (2014) is also available,[74] which includes Health Facility Briefing and Design (part B), Access, Mobility, Occupational Health and Safety (part C), and Engineering Services and Environmental Design (part E). The salient points are highlighted in Table 8.

Table 8.

Indian Guidelines for the urban development and environment conservation

Environment or Urban Development Aspect	Recommendations/Guidelines
Green space[72]	Provision of tree cover at 40,000 Sqm. per 2.5 lacs population 20 Sqm park area per capita 9 Sqm unpaved open space per capita Residential area should be within 15 minutes walking distance to community park 40 sqm green space (park, forest, roadside greenery) per capita
Land-use policies[21]	Integrating land use with public transport Decreased travel time and increased accessibility to the services. Integrating different modes of travel (walking, bi-cycling, electric rikshaw, public transports, etc.) 12–16% of urban land to be reserved/used for recreational purpose Water lands, agricultural areas, green spaces should be balanced with other areas of land use according to the land type and local resources and needs 10% cities peak electricity requirement to be met by renewal resources Waste reduction and effective management
Advisory of water bodies in urban areas[19,73]	Good governance harmonious relationship with water bodies, civic participation in water bodies conservation, lake drainage basin, scientifically driven lake management, Water bodies in an urban area should be identified and fenced in a way it does not obstruct the vision of the people Afforestation to prevent siltation Peri-shore area should be declared as an eco-sensitive area, and dumping of solid waste in this area should be a punishable offence Area surrounding water bodies should be developed as ecological niche with provision of recreational facilities and public welfare activities Conservation of water bodies with a balanced team involving irrigation and water resource experts, Public Works Department officials, health departments’ officials, state government experts Inclusion of all stakeholders in water bodies conservation Adoption of a water-centric approach in concurrent and future urbanization Integrated and time-bound water bodies restoration and protection program Each urban complex should develop their own water plan and water budget to be self-reliant Each urban complex should curb the prevailing reliance on drawing water from nearby water reservoirs to reduce socio-economic imbalance and reduce the impact on the ecosystem of water bodies Provision of water-treatment systems Storm-water sedimentation basin
Green cities[21]	Need of synergies between environment and economic development Effective land-use (e.g.,, mixed-land use) Habitat preservation and restoration (waterbodies, green spaces, open spaces, etc.) Transit-oriented development: Efficient transport management (networks and connectivity, non-motorized transport) Efficient use of resources (reduce, reuse, and recycle water resource, wastes) Efficient energy use (on-site power generation, use of renewal/unconventional sources of energy) Waste management (waste to energy generation) 25–35% area of the cities for/complex for recreation. Basic amenities within 60–800 meters (e.g.,, shopping complex); school, hospital, community center within 1.6–2 kms Need of differently-abled persons, including elderlies and children, should be accounted while planning and developing green cities
Compact cities[21]	Prevents urban sprawl High-density development without compromising QoL Increase proximity and accessibility to transport and other basic facilities Effective land and containment area use (mixed-land use, multi-functional use in time)
Smart-city[21]	A city driven by Information, Communication, and Technology (ICT) Insure transparency, informed, and equitable services Improves livability, walkability, and sustainability Based on smart-grid concept (power generation and supply system) Smart-transport concept: digital view terminals, intelligent roads, and traffic prediction tools Sensitive and facilitatory to the differently abled persons
Micro-climate changes[21]	Improves sustainability and quality of urban resources Considerate to the unique water, sun, humidity, radiation, etc., characteristics of the urban region Energy-efficient landscapes for building and comfortable dwelling Conducive and efficient street orientation (in direction of wind) Provision of water bodies (to decrease surface heat) Open spaces and vegetation: plantation of deciduous plants (Champa and Mulberry) to suit to the sun exposure and wind flow during the different times of a day Green building and green roof
Brown-field development[21]	Green remediation (demolish and reconstruct) or renovation (make building or neighborhood environment-friendly and energy-efficient) of existing sites, which are non-environment-friendly or degrading
Model Building By-laws[18]	High-rise building should have peripheral open space of 6 meters all around (up to 40 meters building, plus 9 meters for height beyond 40 meters), ventilated parking area Building services: adequate and efficient lighting and electricity Barrier-free building and environment (availability of wheelchairs for non-ambulatory individuals, access path of width 1800 mm, with slope gradient <5%) Parking: 2 car parking areas for differently abled persons, maximum distance from the parking area to main entrance should not be >30 meters. Information for wheelchairs should be conspicuous Design for children: floor material should be conducive, provision of drinking water, refuge area in case of fire, signage for different facilities Green building and sustainability provisions: modern building of size >100 sqm; efficient water resource and solar energy, energy-efficient, and waste management system; one tree/80 sqm, compensatory tree plantation 1:3
Hospital built environment[74]	Hospital built design and functioning should be as per the role delineating level (RDL) Good planning relationship (coordination among different health facilities, independence of units, infrastructural growth potential and scope, safety of the patients and staffs) Local design relationships: waiting area for the family members, prayer area, separate dwelling areas for males and females Parking and vehicular access based on the hospital size, number of staffs, community needs, space, disable-friendly, continuous access to hospital facilities, and conspicuous signage
Administrative unit of the hospital[20]	Provision of natural daylights for the staff, especially those working for long hours in the office space Open workstation for easy communication and observation of the patients Administrative facility should be close to main entrance of the hospital building Provision of natural light, privacy (in meeting rooms), acoustic performance (high performance at conference rooms) as per the needs, customized sound level and reverberation time
Admission unit[20,75]	Should be of adequate size to give a sense of space and avoid congestion Privacy in interview room/cubicle Provision of natural light, graduated glaze Usual size of the unit-20-30 beds One consultation room for every five beds Signage: clearly visible bed number outside the bedroom or on the head end of the bed within the bedroom/cubicle. Esthetic: warm and user-friendly Acoustic Guidelines for Indian Healthcare Facilities should be followed
Adult mental health in-patient unit[20]	Provision of safety glass, low maintenance surface Least restriction, accommodate all levels of patient, homely environment Facility should be integrated with other hospital facilities An open garden, with size of garden attached with HDU being 10 m2 Opportunity for moment (both front and back, inconspicuous environmental boundaries, safety provisions) Clearly defined patients’ residential area (especially for delirious patients) A balance between privacy and patients being observed by staff Sound-proof interview room Group therapy area of minimum size 21 m2 HDU: separate area for males and females with a secured courtyard Occupational therapy room of size 1.5 m2 per patient with a minimum room size of 20 m2 Minimum circulation percentage should be 32% to ensure easy movement of the patient, trolleys, walkability, and socialization Acoustic Guidelines for Indian Healthcare Facilities should be followed
Child and Adolescent mental health in-patient Unit[20]	Should enable active family involvement in treatment and activities, including provision of accommodation for the families Able to accommodate children and adolescents with varying levels of emotional, social, and intellectual needs Should collocate with other pediatric activities (e.g.,, with pediatric ward or day care facilities) Outdoor space for recreation Play therapy rooms Large interview rooms to accommodate family members HDU: rooms for the family members with shared ensuites Should be located on the ground floor. Fittings should have a threshold of 15 kgs to prevent self-harm
Acute mental health Emergency Area[20,75]	Acutely disturbed mentally ill patient should not disturb routine ED services and vice versa Acute psychiatry care facility should have least acoustic and visual exposure to routine emergency services Patient flow should be separate to maintain privacy Calming interior, muted colors of the walls/curtains, appropriate lighting Two rooms: interview room (sound proof, safe) and treatment room (should have at least 12 m2 floor area) Acute treatment area: size of at least 9 m2, 2.4 m2 space between beds, light of at least 30000 Lux Provision of short stay ward Separate toilet Should be located in the ground floor, adequate signage, nearby parking facility, natural lights User-friendly and welcoming environment, including ensuring patients’/caregivers/staff safety, to minimize psychological trauma Acoustic Guidelines for Indian Healthcare Facilities should be followed
In-patient accommodation unit[20,75]	Up to 32 beds For specialty care, say maternity and child ward, 20–25 beds optimum 10% of total beds as isolation rooms Easy access to lab services, imaging facilities, etc. Space standards: say for six-bedded room cubicle should have a space of 6500*6750 mm2 Normalization of disabilities and availing aids (e.g.,, wheelchair use) Each room should have a partial blackout facility for privacy and relaxation at the daytime General norms of the Indian health facility guidelines, 2014 to be followed All rooms should have glazed windows or doors to achieve external views and access to natural lights The size of net glazed area of should not be less than 10% of the floor area of the concerned room Acoustic Guidelines for Indian Healthcare Facilities should be followed
Out-patient facilities[20]	Pleasant environment for all patient types (those with chronic medical conditions visiting OPD regularly to first- or second-time visitors for some acute issues) General facilities: mobility aids, space for family with children, adequate lights and acoustic system, provision of privacy (in consultation or procedure room), accessibility (weather-proof vehicle drop-zone), barcode-based registration and investigation systems General norms of the Indian health facility guidelines, 2014 to be followed
Rehabilitation Unit[20]	Friendly and inviting environment Non-institutional, safe, and supportive environment Maximum mobility possible for the inmates Different rehabilitation facilities (pulmonary, occupational, physical medicine, rehabilitation) should be collocated and sharable General norms of the Indian health facility guidelines, 2014 to be followed

ED: emergency department, HDU: high-dependency unit, mixed-land use: refers to different activities taking place concurrently (e.g.,, residential, commercial, recreational) or at different times (commercial and recreational). PWD: public welfare department, QoL: quality of life; Sqm.: square meter

Recommendations

Based on the available literature on the urban health, national and international guidelines/policies, this CPG puts forth some recommendations on the various aspects of the environment (built and natural) and well-being of the people. We have attempted to make the recommendations that are relevant in Indian context, including other LAMI countries, and implementable [See Table 9].

Table 9.

Recommendations on environment, urban development, and psychological well-being

Environmental aspect	Recommendations
Conserving nature and utilizing it for well-being of the human	Government and policymakers should make efforts to conserve the natural environment and harness its potential for health promotion Special consideration must be given to the inherent effect of nature and built environment on mental illness and PWMI Following national and international guidelines (e.g.,, Urban Greening Guideline, 2014; Advisory on conservation and restoration of water bodies, 2013) in their letter and spirit
Designing and implementing Environment-friendly policy	Health and welfare policies must consider the environmental aspect of health and well-being Urban development and environmental health must have health indices, including mental health parameters, as outcome measures Existing guidelines (e.g.,, Building Bye-laws, 2016, URDPFI guidelines, 2015) on urban design and environment conservation must be abided by
Holistic built environment and neighborhoods	The urban health must aim to attain a holistic built environment and neighborhood Built environment and natural surroundings must also incorporate residents, welfare schemes, social services, and conducive neighborhood apart from scientifically robust urban built design
Robust plan for socially disadvantaged population	Effective redevelopment program and comprehensive plan can improve psychological well-being of community members to a greater extent Urban planners must also consider mediating/moderating factors (e.g.,, surrounding of neighborhood) affecting the mental health parameters of urban poor or disadvantaged Creation of smart cities and green cities and adopting a scientific urban design approach (led down by URDPFI, 2015) are vital steps in this context.
Smart cities addressing the unique needs of the vulnerable population	Innovative or smart cities should be equitably distributed. They must consider the unique needs of the vulnerable population (elderlies, Child and Adolescents, PWMI, etc.)
Scientifically informed hospital environment and built area	Hospitals, out-patient, in-patient, and long-stay facilities (dementia care or autism care) must incorporate the scientific urban design frameworks Services in such settings must be welcoming, homely, supportive, respecting rights of the residents, spatially appealing and facilitatory, and promote a contact with the environment and family members/friends. TIC must be implemented in emergency departments at the earliest to enhance experience of the service users and for better treatment outcomes Indian Health facility (2014) guideline is a valuable resource material in this regard, which should be adopted during the hospital planning stage followed by functional stage.
Addressing rural-urban divide and its impact on mental health	Urban areas predispose an individual to develop depression, anxiety, stress, etc. In contrast, unfavorable rural environments (e.g.,, lack of resources) can act as persistent stressors and lead to substance-use-related problems. Both urban and rural areas should be built in a scientifically robust manner Both rural and urban areas should be developed in a way that it can ensure holistic care for individuals and persons with mental illness
Multisystemic model of urban health	The urban development must involve experts from diverse backgrounds (architects, urban planners, researchers, environmentalists, health professionals). Environmental-friendly and favorable built environments must promote and be implemented at both macro (Government plans) and micro levels (building structures, neighborhood characteristics)
Validated instruments to study the urban health	We need to adopt Western tools for the measurement of built environments through robust methodologies or We must develop our instruments that are sensitive and specific to our environment and built design.
Research on the field of urban health:	Greater research is warranted in this area. Interventional study design, longitudinal study, and qualitative study design must be considered to evaluate the effect of environment on mental health and psychological well-being of people.

PWMI: persons with mental illness, TIC: trauma-informed care; URDPFI guidelines: Urban and Regional Development Plans Formulation and Implementation guidelines, 2015

Recommendations on environments, urban development, and psychological well-being

Conserving nature and utilizing it for well-being of humans: Given robust data on positive mental health/well-being of the nature and biodiversity, attempts should be made by the government and policymakers to conserve the natural environment and harness its potential for promoting health and well-being; this should also extend to PWMI. The urban development must take into account how integration (or disruption) of nature/biodiversity can affect (positively or negatively) the well-being of the community members. Scientifically informed urban development projects and redevelopment interventions can have a long-lasting effect on the health of the people. All efforts must be made to preserve or have sufficient green areas, water bodies, and noise reduction.

Environment-friendly policy: All the health and social-welfare-related policies must incorporate the environmental aspects, for instance, air quality, green spaces, water quality, and noise levels, while framing or implementing the policies/program. Similarly, urban development and environment-related projects should include well-being and mental health-related parameters to evaluate the impact of such interventions on the population. Local communities should have an important role in policy/project development and implementation, with their views being considered and valued in decision-making processes. This inclusive, community-led approach, supported by cultural sensitivity and education, will serve as the cornerstone for comprehensive, effective environment-friendly policy.

Holistic built environment and neighborhoods: Research has informed us that it is not only the nature and neighborhood characteristics that influence our health and well-being but also how comprehensive or holistically they have been incorporated. A holistic built environment involves catering to the needs of the community dwellers (including children, adolescents, elderlies, persons with mental illness or physical limitations), incorporating the residential welfare services, surrounding neighborhood of a given neighborhood (relative placement of the green and water spaces and community recreational facilities), and promoting social interaction, including strengthening the social capital and interaction with nature. Therefore, urban development, including residential areas, needs to be holistic and integrative to ensure better health and well-being of the community dwellers. Green cities, compact cities, scientifically sound high-rise, efficient land-use policies, micro-climate changes, and Brown-field development as per the standard guidelines are crucial steps in this regard [Table 8].

Robust urban development program for socially disadvantaged population: Given that socially disadvantaged communities are at higher odds of experiencing the negative impact of the unfavorable built environment (or neighborhood) and the positive role of the poor-friendly urban development program in improving the QoL, well-being, and mental health of these groups of people, urban health must be in forefront while framing development or renovation programs for slum or socially-deprived communities. Smart cities, model-building bye-laws, urban and regional development plans, transit-oriented development, and adopting provisions of Indian health facility guidelines for the differently abled individuals are valuable guiding resources in this context.

Smart cities addressing the unique needs of the vulnerable population: In our country, a smart city project is run in mission mode; with the government infusing substantial resources into this, it is crucial that such proposed digitally driven projects should address the unique needs of the elderlies and children with special needs (e.g., children with autism). A holistic neighborhood environment and appropriately placed services (transport, communication system, Internet, walking zone, recreational centers, schools, social services, etc.) should be designed that would be favorable to elderlies and children. Moreover, such innovative projects should not remain restricted to metropolitan cities or some tier-2 cities but should spread across the states and rural regions; this would prevent the negative impact of otherwise discriminatory urban development and resource allocations on the well-being of the people.

Institutional and hospital facilities and mental health: A user-friendly hospital environment, may it be an in-patient, out-patient, rehabilitation, administrative, or emergency unit, that is welcoming, supportive, least restrictive, connected to the nature, and homely is the cornerstone of well-being and positive mental health of the service users.

For instance, a TIC (user-friendly environment, respect of rights and privacy of the patients/caregivers, effective communication between the staff and service users, and prompt service provisions) should be adopted at the earliest at the emergency health settings in all hospitals. A TIC would prevent re-traumatization of the visitors of the ED, including those with psychological traumas or mental health conditions. Furthermore, an effective peer-support system, preventing over-crowding in such vulnerable places, and ensuring the safety of health providers and patients will promote the service providers' well-being and mental health. Likewise, out-patient, in-patient, or residential facilities need to be aligned to the standards of the Indian health facility Guidelines (2014), particularly those catering to the PWMI, children, and elderlies. Preventing over-crowding, provision of quality water, food, and lights, washrooms, open spaces, spaces for socialization, green environment, recreational facilities, less restrictive environments, non-threatening and supportive treatment regimes, and provision of privacy is vital in promoting the well-being and mental health of the residents of such facilities. Specific and person-centric care for persons with dementia and children with autism and, for that matter, other mental health or physical conditions are vital for ensuring positive residential experiences for these individuals.

Adopting a multi-system and multi-disciplinary model of urban development: A multi-system and multi-disciplinary approach involving urban designers, researchers, administrators, service users, and health professionals is critical in ensuring that the science of urban health is incorporated at the stage of planning and re-development of the urban infrastructure and all system levels (global or national, local, household, and individual). Such an approach will ensure better mental health and well-being of the people. This includes conservation of nature, such as green spaces, water bodies, and biodiversity. Urban development needs to be integrated/synergized with the existing natural environment. Adhering to the guidelines of the Urban Greening Guideline (2014), advisory on conservation and restoration of water bodies (2013) and so on could be vital in concerning this.

Developing instruments to study urban health: As highlighted previously, we do not have a validated tool that can accurately assess the built environment and its effect on people's health. This lack significantly affects the growth of research on urban health in our country. Therefore, efforts should be made to develop our own validated instruments to study the impact of the environment on people's health or adopt a methodologically effective way of measuring tools developed by high-income countries. Various stakeholders must be part of such tool development so that these instruments remain comprehensive and useful in different settings and population groups.

Research on the field of urban health: Greater research, particularly randomized control trials and longitudinal study designs, is required in urban health. Qualitative studies must be conducted to elucidate the granular information on this topic, including the mechanism behind change brought out by innovative urban health design. Robust methodologies should be utilized to study the causal relationship and path analysis of the built environment and mental health parameters. Research on this topic must involve different stakeholders, including experts from diverse fields, so it can be implementable at the ground level and widely applied. Similarly, various mediating and moderating factors (e.g., individual characteristics, gene–environment interaction, neighborhood characteristics, quality of the natural environment) must be incorporated and analyzed through sophisticated statistical tests so that they can be appropriately considered while planning urban development and hospital or workplace environments.

CONCLUSION

Environment, well-being, and mental health are intricately related. A conducive neighborhood can be health-promoting; in contrast, an unfavorable environment can house stress and various psychological problems. Urban planners, researchers, and health professionals should work in tandem to harness the inherent potential of the natural and built environment to bring about a positive change in lives of the community dwellers or at least prevent the ill effect of otherwise poorly planned urban development. Following urban development and natural resource conservation guidelines/policies in their latter and spirit can pave a way in long run, including ensuring sustainable urban development. Greater research in this area, particularly from India, is required in this topic.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.