Pain Management for Older Adults Across the Cognitive Trajectory

Abstract

Purpose of review:

This review investigated current research on the relationship between chronic pain and cognitive performance, subjective cognitive decline, and dementia. In addition, we reviewed current research on pain management in older adults across the cognitive trajectory.

Recent findings:

Chronic pain remains a common problem in older adults. A new, international classification system highlights the complexity of chronic pain syndromes. Research supports relationships between chronic pain and changes in cognitive performance in generally healthy adults. Evidence also supports associations between pain and subjective cognitive decline, which is considered a possible precursor to dementia. The impact of dementia on pain expression is also reviewed. To manage pain in older adults, we present a multimodal pain management hierarchy that includes pharmacological and non-pharmacological treatments. To avoid the risks and side effects of analgesics, non-pharmacological treatment is recommended as the first line therapy for chronic pain. Medical cannabis and music therapy are two non-pharmacological treatments that have been the focus of substantial recent research; evidence supports their effectiveness in reducing pain and both strategies warrant further investigation.

Summary:

Chronic pain is associated with different levels of cognitive decline across the cognitive trajectory. Medical cannabis and music therapy are the two emerging non-pharmacological treatment methods. Clinical studies with rigorous research design are needed to further investigate the effects of these two strategies on pain relief in older adults.

Introduction

Chronic pain is one of the most prevalent and significant health problems in the United States. It is estimated that 50 million American adults experience chronic pain daily [1]. Defined as pain that persists or recurs for more than 3 months, chronic pain is associated with suffering and interference with daily functioning [2]. Recently, the International Association for the Study of Pain (IASP) collaborated with the World Health Organization to develop a classification system to better define chronic pain for diagnostic and treatment purposes [2]. In this system, chronic pain is an overarching, “parent” International Classification of Diseases (ICD-11) code that includes chronic primary pain syndromes (e.g., pain conceived as a disease, such as fibromyalgia) and chronic secondary pain syndromes (e.g., pain which begins as a symptom of another disease, such as chronic cancer-related pain or chronic neuropathic pain). The goal of this systematic classification of chronic pain is to enhance understanding of the complexity of chronic pain syndromes, to improve access to specialized, multimodal treatment, and to provide more precise operational definitions for research purposes. This systematic classification is a significant scientific and clinical advancement for all patients but especially for older adults who experience a disproportionate burden of chronic pain syndromes [2].

Chronic pain is a common problem among older adults. It is estimated that 25%−33% of older adults in the United States are affected by chronic pain [2, 3]. Chronic pain is associated with a wide range of negative consequences for older adults, including physical disability, depression, anxiety, decreased social interaction [4], falls [5], suicide [6], and a lower quality of life [7]. In addition, chronic pain contributes to significant economic burden [8, 9].

Chronic pain is also associated with cognitive functioning in older adults. Most of the research to date has focused on pain in older adults with dementia. Specifically, research has documented that people with dementia have impaired ability to self-report that hinders pain assessment and management [10]. Work in this domain has largely focused on documentation of undermedication for pain and the need for alternative assessment tools that focus on behavioral indicators of pain. However, there is a growing body of research that focuses on the effects of pain on cognitive status in adults without dementia. This research has focused primarily on the impact of chronic pain on cognitive performance based on neuropsychological tests. There is also a growing body of research focused on the effects of pain on subjective cognitive decline, which is considered a precursor to dementia [11].

In the following section, we will summarize the current research in these areas of clinical and research relevance. Because cognitive status is on a continuum, we will first discuss current research related to pain and cognitive status in general, followed by subjective cognitive decline, and finally dementia.

Pain in Older Adults Across the Trajectory from Cognitively Intact to Dementia

Pain and Cognitive Status

Several recent studies have examined the relationship between chronic pain and cognitive status in cognitively intact adults with pain syndromes. Investigators focused on changes in five key cognitive domains: Executive Function, Attention and Working Memory, Language, Memory, and Visuospatial [12–15]. In a key systematic review, Moriarty and colleagues reported that approximately 50% of adults living with chronic pain reported changes in cognitive performance. Most of the studies in this review were conducted in clinical populations of adults with specific pain conditions (e.g., back pain, headache, fibromyalgia). Across the studies, there was evidence that chronic pain was associated with poorer cognitive performance in the domains of attention, working memory, executive functioning, and general memory. The study findings varied in the strength and direction of the relationships across studies, chronic pain conditions, and domain of cognition investigated.

It should be noted that there are few studies that focused specifically on the relationship between pain and cognitive performance in older adults. Several investigators reported that higher pain intensity was associated with lower performance in the cognitive domains of memory, executive function, speed of processing, and attention [12, 14, 16–19]. One of the few longitudinal studies of pain and cognition reported that older adults with chronic pain have 9.2% (95% CI, 2.8%−15.0%) greater risk of memory decline and 2.2% increased probability of dementia after 10 years [20]. Taken together, these studies demonstrate that chronic pain is associated with lower cognitive performance at a pre-clinical level in otherwise cognitively healthy adults, which may place older adults at risk for cognitive decline.

Pain and Subjective Cognitive Decline

Given the increasing number of older adults diagnosed with some form of dementia, researchers have begun to focus on subjective cognitive decline (SCD), defined as self-reported worsening or increased frequency of confusion or memory loss over the previous 12 months [21]. SCD is considered an early symptom of Alzheimer’s disease and related dementias [21, 22]. Several recent studies have reported an association between chronic pain and subjective cognitive decline. Using data from a population-based study, Horgas and colleagues [23] reported that adults (55.3% were over age 65) who reported moderate pain were two times as likely to report SCD and those with severe pain were more than three times as likely to report SCD compared to those without pain. Bell and colleagues [24] reported that older adults with chronic pain had a 13% increased risk of reporting SCD, based on data in another population-based study. More research is needed to investigate the relationship between pain and SCD, as improved pain management and early recognition of SCD may help to prevent or slow the progression of cognitive decline [25–27].

Pain and Dementia

Over the past several decades, there has been a significant body of research focusing on pain in adults with Alzheimer’s disease and related dementias (ADRD). People with ADRD have decreased ability to self-report pain due to progressive cognitive (e.g., remembering, thinking, and decision-making) and verbal declines (e.g., word-finding deficits and speaking) [10]. Due to brain changes associated with ADRD, it is often assumed that people with dementia do not experience pain. However, there is no empirical evidence that older adults with dementia experience less pain, and in fact, may be at higher risk for experiencing more pain [10]. People with the two most common types of dementia, Alzheimer’s dementia and vascular dementia, have more emotional responses to pain and display stronger facial indicators of pain than those without dementia [10]. Thus, lack of self-report does not mean lack of pain. Instead, impaired self-report should signal the need for heightened pain assessment to detect signs of pain in this vulnerable population.

Due to the memory and communication changes associated with ADRD, different approaches are needed to assess pain in this population. Evidence supports the fact that pain is underassessed and undertreated in older adults with dementia [28]. For those with mild-moderate dementia, self-report is often possible to obtain if simple numeric or verbal descriptor pain assessment scales are used [28, 29]. For those with moderate to advanced dementia who are unable to provide self-report, a hierarchical approach to pain assessment is recommended, consisting of the following steps: (1) ascertain potential causes of pain, (2) attempt to obtain a self-report of pain, (3) observe behaviors, (4) seek input from family and caregivers, and (5) attempt an analgesic trial [30]. Pain is often expressed through facial expression (e.g., grimacing), body movements (e.g., guarding, bracing, or rubbing), and vocalizations (e.g., groaning, verbal expressions) [28]. Changes in behavior, such as aggression, agitation, resisting care, wandering, or changes in mood or mental status (e.g., confusion, crying) when these behaviors are not typical, may also indicate pain in people with dementia [31].

There are number of tools available to assess pain in older adults with dementia [32]. One of the most commonly recommended tools is the Pain Assessment in Advanced Dementia (PAINAD) scale [33], which is a short, easy-to-use tool appropriate for people with advanced dementia [34].

Pain Management in Older Adults

Managing pain in older adults is based on comprehensive pain assessment to guide the best combination of pharmacological and non-pharmacological strategies to achieve optimal pain control. Among older adults with dementia, pain management may also reduce behavioral and psychological symptoms of dementia (BPSD), such as agitation and wandering.

Figure 1 presents a hierarchy of multimodal pain management that demonstrates the links between pain levels, pharmacological and non-pharmacological treatment modalities. Pharmacological pain management is the mainstay of pain therapy for older adults with or without cognitive decline or dementia. Medications may not be completely effective in relieving pain and are associated with adverse effects and drug-drug interactions due to polypharmacy in older adults [35–39]. There are ample resources that provide in-depth information on opioid, non-opioid, and adjuvant medications to treat pain [28, 40, 41].

Figure 1. Assessment and Multimodal Pain Management in Older Adults.

Copyright 2020 K. Herr. Modified and used with permission from copyright holder, K. Herr, University of Iowa, College of Nursing on May 2, 2023.

Non-pharmacological pain treatments are recommended as a first line therapy or as a supplement to pain medications [28, 35, 41]. Non-pharmacological interventions for older adults include but are not limited to psychological interventions such as cognitive behavioral therapy, physical activity, complementary and integrative health (CIH) therapies, creative activities (e.g., painting, singing, play), physical modalities (e.g., massage, acupressure, warmed blankets), and comfort measures (e.g., heat, cold, rest), and support measures (e.g., prayer and spiritual activities, pet therapy) [40, 42, 43]. Key considerations when implementing person-centered non-pharmacologic therapies include the following [32]:

• Before selecting a non-pharmacologic regimen, consider the older adult’s current co-morbidities, physical ability, personal preferences, and their ability to access selected treatments in addition to its evidence of effectiveness for different mechanisms or types of pain.

• Tailor pain management treatments to the individual person’s current cognitive status, mood, and behavior to guide the most appropriate pain treatment. As cognitive abilities change and decline, different treatments may be needed. For example, choose cognitive-based therapies (guided imagery, reminiscence, mindfulness meditation) carefully as some older adults with varying levels of cognitive or intellectual disability may not be able to use these due to challenges in ability to self-regulate, attention/focus, memory, and understanding.

• Provide nonpharmacologic interventions in a calm and private area with reduced environmental stimuli.

• Engage caregivers (informal, formal, family) in selecting and applying select nonpharmacologic treatments and determine expectations and ability to manage older adults’ pain.

• Older adults with dementia may not be able to verbalize the helpfulness of treatments, and other indicators such as behaviors, activity patterns, function, and mood should be evaluated to determine pain relief.

In the following sections, we will elucidate current research on two types of non-pharmacological pain interventions: cannabis and music therapy in older adults. These were selected from the array of non-pharmacological treatments due to their current attention in the empirical and clinical literature. Both cannabis and music therapy may be applicable to older adults across the cognitive trajectory.

Cannabis

As of 2023, 38 states, 3 territories, and the District of Columbia have legalized the medical use of cannabis and cannabinoids [44]. Treating chronic pain is the most common reason patients cite for using cannabis [45]. A recent survey of adults (age 18+) with chronic pain who lived in states with active medical cannabis programs found that 25.9% of respondents reported using cannabis to manage chronic pain in the past 12 months [46]. More than 50% of participants reported that they used medical cannabis to substitute for other analgesic medications including prescription opioids. Bell and colleagues [45] recently published clinical practice guidelines for cannabis and cannabinoid-based medications (CBM) derived from the cannabis plant in the management of chronic pain and co-occurring symptoms. The expert panel evaluated 19 systematic reviews and 51 original research studies. They concluded that CBM demonstrates moderate benefit in the management of chronic pain, comorbidities (e.g., sleep problems, anxiety, appetite), and other symptoms associated with painful chronic conditions (e.g., fibromyalgia and arthritis) [45]. These authors provide important recommendations for managing CBM as a primary, adjunct, or opioid-sparing pain treatment.

These clinical guidelines are not specific to older adults, but they do address CBM for arthritis and other chronic pain conditions common among older adults. They also highlight adverse effects and administration recommendations that are relevant for older adults. For instance, adverse effects differ according to type of cannabinoid product: cannabidiol (CBD), tetrahydrocannabinol (THC), or THC/CBD combinations products, which vary in ratios. THC products demonstrate the strongest evidence for reducing pain, but is associated with more adverse effects [45]. Common side-effects of cannabinoid include drowsiness, dizziness, disturbances in attention, and dry mouth. The expert panel concluded that these side-effects are non-serious as compared to the adverse effects associate with opioids [45]. For older adults, however, these adverse effects may increase the risk of falls and cognitive impairment, potentially serious events for older adults. In particular, TCH has greater psychoactive potential which can be particularly problematic in older adults with dementia and who may already have BPSD. In addition, CBM products vary in their route of administration. These include smoking, vaping, topical agents, and oral capsules, oils, or sprays. For older adults, the oral route may be more appropriate as it avoids inhalation risks, has a longer duration of action (6–8 hours), and is easier to administer as a standardized dose in oil or capsule formulation. It is also important to consider age-related pharmacokinetics, liver disease, and other medications that may interact with THC or BCD. In general, clinical guidelines for CBM mirror those for medication administration in older adults: start low, go slow, and monitor for effectiveness and side-effects [45]. More evidence is needed to support the use of CBM in older adults [47, 48].

Cannabinoids for pain management would most likely be used by cognitively intact older adults or those with SCD. However, there is recent attention to the use of cannabinoids in the treatment of dementia. A Cochrane Review in 2021 evaluated four published studies of the effects of TCH on cognitive function, BPSD, and adverse events in a small sample (N=126) of older adults with varying types of dementia [49]. The authors were unable to conclude that cannabinoids had any beneficial or harmful effects on dementia. Given the overall efficacy of cannabinoids in reducing pain, the question remains whether they have similar effects in older adults with dementia. Pain is a known trigger for BPSD, such as agitation, wandering, sleep disorders and eating disorders [23]. These symptoms are associated with more rapid dementia progression and higher healthcare costs [49]. Thus, cannabinoids may indirectly improve BPSD through the reduction in chronic pain. This hypothesis warrants investigation in adequately powered, well-designed studies.

Music Therapy

Music therapy is an emerging symptom management intervention for older adults with a number of chronic conditions (e.g., Parkinson’s Disease, dementia), including chronic pain [50, 51]. The powerful effects of music, including audio analgesia, have been demonstrated in healthy adults [52], and may be of great benefit to older adults with dementia and pain particularly during procedures that may cause pain, discomfort, or agitation (e.g., dressing, bathing, wound care, etc.). While music therapy requires some level of cognitive engagement, it is an easy, convenient, and safe intervention to implement especially for people with dementia or SCD [53, 54]. The therapeutic use of music can be used across the cognitive spectrum but modifications to the delivery of music-based intervention may be needed as the cognitive impairment progresses.

Music therapy activates several brain regions, and based on the pain gate theory, music diverts attention from the painful stimulus, thereby altering the perception of pain [52, 55]. Further, music has a direct effect on the autonomic nervous system through increase of neurotransmitters, such as serotonin and dopamine [56]. Together these elevate mood and improves concentration, memory, and sleep all of which are affected in people with chronic pain. Most studies have focused largely on younger adults or healthy individuals rather than examining the effects of music interventions on chronic pain relief for the older population [57]. Few studies focus on music therapy for chronic pain relief in older adults with dementia in the recent two decades (2000 to 2023). Nonetheless, several research studies have shown that music therapy reduces pain, depression, and anxiety [51, 58], and to a lesser degree BPSD in older adults [59]. The analgesic and comforting effects of music may be synergistically amplified when paired with other adjunct therapies such as light massage, exercise, and guided imagery.

Currently there is no standardized application of music therapy or music-based interventions (Table 1), but tailoring the music to the preferences, cognitive status, and culture of the older adult with dementia will enhance intervention effects. While individualized music therapy may be preferred, heterogeneity in application are also simultaneously methodological limitations in observational studies and clinical trials. Subsequently, more rigorous, high-quality research on music therapy is needed for older adults with pain and cognitive changes. It is important to assess pain before and after music-based intervention to determine whether the strategy was helpful in reducing pain intensity or observational pain tools.

Table 1.

Music Therapy Considerations

Intervention Element	Description or Application	Application considerations
Interventionist	Therapist- or clinician-led, patient-initiated, family or caregiver-initiated	The setting and cognitive status of the person will guide who serves as interventionist.
Type of music	May include diverse genres and type of music may be selected by the interventionist or the participant	Consider the person’s culture, age, and preferences when possible when selecting a genre of music.
Music delivery	Live music Recorded music	Live music may evoke additional sensory disturbances and exacerbate agitation.
Patient involvement	Passive listening Active performance (e.g., singing, playing an instrument)	Engage the individual based on their cognitive abilities. Someone with end-stage dementia may not be able to vocalize or verbalize words to a song.
Dosage/duration of intervention	Varies from daily to twice per week for 30–60 minutes	The concentration level of the individual may dictate the how long a person can engage.
Participant level	Group-based Dyad Individual	Keep in mind preferences of the older adult and current behaviors that may indicate a need for one-on-one sessions versus group session.
Intervention time of day	Any time during the day or night	Initiate music therapy during the times when the individual may report more pain or exhibit more pain-related behaviors.
Setting	Acute, long-term, home, hospice	Acute and long-term care settings may offer live music therapy, while end-of-life facilities and homes will likely use recorded music.

Conclusions

In summary, pain is a significant problem for many older adults. There is a growing body of literature that suggests that pain is associated with cognition across the trajectory from cognitively intact to cognitively-impaired persons with dementia. The direction of the relationship varies such that chronic pain is associated with poorer cognitive performance and higher subjective cognitive decline whereas dementia is associated with less ability to verbally report pain. Across all levels of cognition, pain management is key to maximizing function and quality of life in older adults. Effective pain management includes pharmacological and non-pharmacological strategies and a hierarchical, multimodal approach is recommended. Two emerging pain management approaches include cannabinoids and music therapy. The body of evidence to support these interventions and recommendations for use are presented.