A new study published in Journal of Adolescent Health has revealed that adolescents who experience high levels of loneliness are more likely to develop depression, PTSD, and stress-related conditions later in life, but do not experience a major impact upon their physical health.
Loneliness is more than just feeling alone; it is the distress experienced when social connections do not meet expectations. Research has long shown that social isolation and loneliness in adulthood can contribute to chronic illnesses such as heart disease, dementia, and depression. However, there has been limited research on how an increase in loneliness during adolescence affects long-term health outcomes.
Led by Eric S Kim from the University of British Columbia, Canada, the research team sought to investigate whether loneliness in adolescence predicts poor health and well-being in adulthood.
The researchers used data from the National Longitudinal Study of Adolescent to Adult Health, which recruited over 11,000 U.S. adolescents, who were on average 15 years old.
Participants were first surveyed in the mid-1990s when they were in grades 7 to 12, answering questions about how often they felt lonely.
Kim and colleagues then followed up with them over the next 11 to 20 years, collecting information on 41 different health-related outcomes, including physical health conditions, mental health disorders, psychological well-being, and social relationships.
The participants were then divided into three groups based on their responses: those who reported rarely feeling lonely, those who felt lonely sometimes, and those who felt lonely often. The researchers then compared health outcomes across these groups while accounting for other factors like socioeconomic background and family structure.
The most striking results were in the area of mental health. Adolescents who experienced higher levels of loneliness were significantly more likely to be diagnosed with PTSD, depression, and stress-related conditions in adulthood.
Those who reported feeling lonely frequently were nearly twice as likely to be diagnosed with PTSD. Additionally, the likelihood of experiencing depression later in life increased by about 25%. Participants also reported lower happiness and job satisfaction.
Interestingly, while loneliness had a strong connection to mental health, it did not have a major impact on physical health. The only notable association was a slightly higher likelihood of developing asthma. Researchers did not find significant links between adolescent loneliness and conditions such as cancer, obesity, diabetes, or heart disease.
Another unexpected finding was that loneliness did not appear to influence behaviors like smoking, drinking, or drug use. The study also found no connection between adolescent loneliness and social activities, or civic engagement (e.g. voting, volunteering). However, the results demonstrated that loneliness was associated with lower romantic relationship quality and higher perceived discrimination.
Kim and colleagues concluded, “the impact of changes in adolescent loneliness may manifest primarily in mental health and social-emotional domains.”
While the study provides valuable insights, researchers note some limitations. For instance, loneliness was measured using a single-item question, which may not fully capture its complexity.
The study, “Loneliness During Adolescence and Subsequent Health and Well-Being in Adulthood: An Outcome-Wide Longitudinal Approach,” was authored by Eric S. Kim, Renae Wilkinson, Julianne Holt-Lunstad, and Tyler J. VanderWeele.
