Association of loneliness with mental disorders in Korean adults: national mental health survey of Korea 2021.

Purpose: Loneliness is a risk factor for mental and physical disorders. Rapid individualization, with increasing associated social burden, is a contributing factor to loneliness among Koreans. This study aimed to investigate the relationship between loneliness and mental disorders, as well as to determine whether long-term loneliness is a factor predicting the occurrence of mental disorders in adults.

Methods: The National Mental Health Survey of Korea 2021, a nationally representative survey on mental disorders, was conducted. Responses from 5511 participants were collected using the Korean version of the Composite International Diagnostic Interview for Diagnostic and Statistical Manual of Mental Disorders fourth edition, Structured Clinical Interview for Internet Gaming Disorder, and the World Health Organization Adult Attention-deficit Hyperactivity Disorder (ADHD) self-report scale. Loneliness and its duration were investigated among these participants.

Results: Loneliness was reported by approximately 2.9% of the general population. Loneliness was associated with an increased adulthood prevalence of alcohol use disorders, nicotine use disorders, depressive disorders, anxiety disorders, adult ADHD, and internet gaming disorders. Long-term loneliness was significantly associated with an elevated risk of alcohol use disorders, nicotine use disorders, depressive disorders, and anxiety disorders. Internet gaming disorder was associated with loneliness lasting > 1 year.

Conclusion: Various adult psychiatric disorders were associated with loneliness. The significant dose-effect relationship indicated the importance of early detection of and intervention for loneliness to reduce its negative consequences on mental health.