Improving Interventions for Loneliness and Social Isolation in Late Life: The Potential Role of Positive Affect

Social isolation and loneliness are robust predictors of negative physical and mental health in late life. Loneliness is associated with structural and functional brain abnormalities in the default mode network as well as circuits supporting attention and visual processing.¹ With aging, cognition, and physical health decline and the need for social support increases. During this vulnerable period, older adults experience shrinkage of social networks and increased social isolation.² Among nondepressed adults, loneliness is associated with increased risk of physical problems and even mortality.^3,4 Despite progress in development of loneliness interventions, the underlying psychosocial and neurobiological mechanisms of treatment success remain relatively understudied. Understanding the mechanistic pathways through which therapeutic interventions target loneliness can enhance treatment efficacy and therapeutic outcomes in late life.

Davidson et al. (2021)⁵ conducted a survey in a sample of 429 community-dwelling older adults and found that 1) Higher levels of positive affect were associated with lower loneliness and 2) positive affect was linked to satisfaction with social activities, even when controlling for age, gender, and negative affect. Notable strengths of the study include the large sample size, comprehensive measures of social functioning, and their examination of these critical constructs in a non-clinical sample. Their sample had low rates of depression and mental health distress, yet participants varied in levels of loneliness and social isolation, with nearly a third reporting high levels of loneliness. Davidson and colleagues proposed that positive affect may be a potential mechanism of action in interventions that reduce loneliness and social isolation. Helping individuals to increase their levels of joy, happiness, and satisfaction during social interactions could in turn reduce perceived social isolation.

These findings align with recent studies in geriatric mood disorders suggesting that increased social engagement predicts improved mental health outcomes. Engagement in social activities led to reduced depression severity as well as increased behavioral activation⁶ and quality of life⁷ in “Engage” psychotherapy for late-life depression. Conversely, low perceived social support was the strongest predictor of risk for poor response to psychosocial interventions for late life depression.^8,9 “Engage,” a stepped psychotherapy, is aimed to target deficits in the reward system, through exposure of older adults to pleasurable meaningful activities.¹⁰ Increased activation in reward regions during “Engage” contributed to increased behavioral activation among depressed older adults.¹¹ If patients do not show clinical improvement, “Engage” therapists introduce strategies to address barriers to response, including difficulties in emotional regulation, apathy, or negativity bias. In the context of social activities, patients can present with high levels of negative affect, lack of motivation and interest in social engagement, or overly negative interpretations of interpersonal interactions. These studies did not directly examine individuals’ positive and negative affect during engagement in pleasurable social activities. Future studies could potentially test whether the perceived affective valence during social engagement contributes to altered activation in target brain regions impaired in late life depression.

An important limitation of Davidson et al. (2020)⁵ study was its cross-sectional data, which precluded examination of causality and temporal dynamics of the studied variables. Future work could expand the current findings and test the longitudinal relationships between positive and negative affect, loneliness, and social isolation over time. It is likely that there is a bidirectional relationship between positive affect and loneliness, such that individuals with a history of loneliness who lack social connection, are less likely to experience high levels of positive affect during social interactions. This may be due to persistent negative interpersonal cognitions, fear of rejection, and abandonment, or a lack of meaningful relationships with supportive others. Delineating the casual relationships between these factors can guide intervention development. The current study provides preliminary evidence on the potential role of positive affect enhancement as a mechanism of action in interventions for loneliness in older adults. Future studies could test the proposed investigation and identify the neurobiological mechanisms underlying changes in affect during loneliness interventions.

DATA STATEMENT

The data has not been previously presented orally or by poster at scientific meetings