Study Identifies Loneliness and Prior Mental Health as Key Predictors of Psychological Distress During First Year of COVID-19 Pandemic

Predictors for experiencing psychological distress in the first year of the COVID-19 pandemic included a person’s likelihood of having a prior psychiatric diagnosis, loneliness, and stress related to social distancing, according to a new large longitudinal study published in Nature Mental Health. The study was conducted by researchers from the National Center for Complementary and Integrative Health and the National Institute of Mental Health and funded by the National Institutes of Health (NIH) Intramural Research Program.

Determining the effect that the COVID-19 pandemic had on mental health has been challenging and results from past studies have been mixed because of the variance in pre-existing risk, disease impact, and public policy across individuals, time, and locations. This study involved longitudinal, within-person analyses, which compared changes at regular intervals over time both within and across individuals, to identify whether pandemic-related changes affected mental health over time. The research helped clarify the relationships among psychiatric vulnerability (likelihood of having a psychiatric diagnosis), loneliness, social distancing policies, social isolation, and mental health during the pandemic.

The 3,655 participants who enrolled in this internet-based study reported on their mental health, physical health, and COVID-19–related circumstances every 2 weeks for 6 months during the first year of the COVID-19 pandemic. Over half of the participants reported previous psychiatric treatment. Prior to the pandemic, some of the participants had undergone clinical evaluations and psychiatric diagnostic interviews at NIH, providing a way for the researchers to use machine learning to assess likelihood of psychiatric vulnerability on participants who had not undergone psychiatric evaluations. The researchers also included regional social distancing estimates in their analyses.

Findings from the research showed that across individuals, psychological distress, the study’s main measure of mental health, was higher in those with a likely psychiatric diagnosis upon enrollment than in those without one throughout the entire study period. There were also strong associations between psychological distress and loneliness, with lonelier people reporting higher distress levels across the whole study period, and people reporting higher distress at times when they reported more loneliness, regardless of psychiatric history or average loneliness. The researchers found that the associations between loneliness and psychological distress were as strong as the association between psychological distress and baseline psychiatric vulnerability.

Social isolation (whether an individual was living alone or with others) was associated with both psychological distress and loneliness. However, individuals living alone reported less psychological distress but greater loneliness than those living with others. And individuals living with others reported less loneliness but more psychological distress as household size increased.

The authors also asked whether distress and loneliness were related to social distancing, and found that the strongest predictor was the amount of stress people reported in relation to social distancing. The findings suggested that when individuals felt lonely in response to the stress of social distancing, they reported greater psychological distress than when they did not feel lonely in response to social distancing. The association between loneliness and the stress of social distancing was strongest in individuals living alone, while the association between loneliness and psychological distress was strongest in those who were psychiatrically vulnerable.

The authors acknowledge that the study’s findings are correlational and not causal, but they say that the strong associations identified in the research support public health efforts to address loneliness and social isolation to improve mental health, especially if social distancing policies are considered or put in place in the future.