Loneliness takes a long-term toll on mental health

Childhood loneliness can send ripples through adulthood, leading to anxiety and depressive disorders, as reported in a recent study.

“[L]oneliness is relatively common and is observed by parents and children early in life,” according to the investigators.

The findings suggest that “loneliness is not a transient dysphoric state … and has the potential to have lifelong effects on one’s social and emotional functioning,” they added.

In the study, a total of 1,420 individuals completed the structured Child and Adolescent Psychiatric Assessment interview up to eight times in childhood (ages 9–16; 6,674 observations) to report loneliness, associated psychiatric comorbidities, and adversities. They also underwent up to four follow-up assessments in adulthood (ages 19, 21, 25, and 30; 4,556 observations of 1,334 participants) using the structured Young Adult Psychiatric Assessment Interview for psychiatric outcomes.

Both self- and parent-reported childhood loneliness were associated with adult self-reported anxiety (p=0.002) and depressive outcomes (p=0.002), but not with adult substance use disorders (p=0.246). This multi-informant approach, according to the investigators, should effectively eliminate the potential for bias when relying only on self-reported data. [Psychol Med 2021;doi:10.1017/S0033291721001422]

The observed associations persisted despite controlling for childhood-assessed adversities and psychiatric comorbidities and were stronger for self- than for parent-reported childhood loneliness.

Why early childhood loneliness precedes mental health outcomes over time may be explained by the evolutionary theory of loneliness. It posits that lonely people are more driven to seek potential relief from unpleasant events, such as hunger, thirst, and pain. [Twin Res Hum Genet 2007;10:267-273]

This relief-seeking behaviour takes the form of (a) heightened vigilance for social threats that comes with increased anxiety, hostility, and social withdrawal to avoid predation, (b) greater sleep fragmentation, (c) elevated vascular activity, (d) decreased impulse control (eg, prepotent responding), and (e) greater depressive symptomatology. [Psychol Bull 2014;140:1464-1504]

“Our findings may have implications for future research and clinical practice. First, increased opportunities for social contact and social support, and improved social skills may reduce the risk of future psychiatric disorders in lonely children. However, such study needs to be targeted at the subjective experience of loneliness rather than merely at increasing objective social contacts,” the investigators pointed out.

“Overall, early interventions targeting children's maladaptive social cognitions may be an efficient way to alleviate … subjective feelings of loneliness. Such interventions would have to be implemented in a developmentally appropriate way given the social, cognitive, and emotional changes from childhood to adolescence,” they added.

The next step in the research is to identify who is at risk for such long-term effects of loneliness and how this risk is propagated across significant developmental transitions, the investigators said.