Adolescents with a triad of low physical activity, high media use, and reduced sleep comprise an ‘invisible-risk’ group that displays a high prevalence of depression and psychiatric symptoms. The findings of this new international study by researchers at Karolinska Institutet are published in the February 2014 issue of World Psychiatry.
For the study over 12,000 adolescents (14-16 years old) in eleven European countries responded to questionnaires charting different risk behaviors and their link to psychiatric symptoms. According to researchers, "As many as nearly 30 percent of the adolescents clustered in the 'invisible' group showed a high level of psychopathological symptoms."
While the 'high' risk groups are traditionally easy to identify based on behavioral problems or alcohol and drug use—parents and teachers are often unaware that adolescents in the 'invisible' risk group are at risk, according to Vladimir Carli, at the National Centre for Suicide Research and Prevention of Mental Ill-Health (NASP) at Karolinska Institutet, first author of the study.
Statistical analyses of the results identified three risk groups among the adolescents. Individuals who scored high on all examined risk behaviors clustered in the ‘high-risk’ group (13% of the adolescents). The ‘low-risk’ group (58%) consisted of responders who had no or very low frequency of risk behaviors.
In an unexpected finding, a third group—which the researchers labelled the ‘invisible-risk’ group—was identified. Youths in this group were characterized by a combination of: high media use, sedentary behavior, and reduced sleep. These behaviors are generally not associated with mental health problems by observers such as teachers and parents. Surprisingly, adolescents in the ‘invisible’ risk group had similar prevalence of suicidal thoughts, anxiety, subthreshold depression and major depression as the ‘high’ risk group.
The study is the first to estimate the overall prevalence of a wider range of risk behaviors and lifestyles and their association with mental health issues among European adolescents. The results indicate that both risk behaviors and psychopathology are relatively common in this population.
Invisible risk behaviors like heavy media use, lack of physical activity, and reduced sleep can become habitual. Over time the depressive symptoms caused by these lifestyle choices can potentially snowball leading to psychopathology. Early identification and interventions could prevent these three ‘invisible risks’ from leading to emotional psychiatric symptoms such as depression, anxiety, and thoughts of suicide.
Lack of Sleep Can Trigger Genetic Risk for Depressive Symptoms
Two other recent studies of adult twins and adolescents both found a link between sleep duration and depression. A new study of 1,788 twins is the first to demonstrate a gene-environment interaction between habitual sleep duration and depressive symptoms. Another study of 4,175 individuals between 11 and 17 years of age is the first to document reciprocal effects for major depression and short sleep duration among adolescents.
A study titled “Sleep Duration and Depressive Symptoms: A Gene-Environment Interaction” of adult twins and a community-based study of adolescents reported links between sleep duration and depression. The findings are published in the February 1, 2014 issue of the journal Sleep.
Principal investigator of the study, Dr. Nathaniel Watson, associate professor of neurology and co-director of the University of Washington Medicine Sleep Center in Seattle concludes that optimizing sleep may be one way to maximize the effectiveness of treatments for depression such as psychotherapy.
Another study of 4,175 individuals between 11 and 17 years of age is the first to document reciprocal effects for major depression and short sleep duration among adolescents using prospective data. The results suggest that sleeping six hours or less per night increases the risk for major depression. This creates a double whammy because depression itself increases the risk for insomnia among adolescents.
"These results are important because they suggest that sleep deprivation may be a precursor for major depression in adolescents, occurring before other symptoms of major depression and additional mood disorders," said principal investigator Dr. Robert E. Roberts, professor of behavioral sciences in the School of Public Health at the University of Texas Health Science Center. Roberts recommends, "Questions on sleep disturbance and hours of sleep should be part of the medical history of adolescents to ascertain risk."
"Healthy sleep is a necessity for physical, mental and emotional well-being," said American Academy of Sleep Medicine President Dr. M. Safwan Badr. "This new research emphasizes that we can make an investment in our health by prioritizing sleep."
Conclusion: The Statistics of Depression are Alarming
The Centers for Disease Control and Prevention reports that about nine percent of adults in the U.S. meet the criteria for current depression, including four percent with major depression. The National Institute of Mental Health reports that depressive disorders have affected approximately 11 percent of U.S. teens at some point during their lives, and three percent have experienced a seriously debilitating depressive disorder.
Clearly, there are no easy answers for combating depression. In a recent Psychology Today blog post titled, "Revolutionary Ideas About the Science of Depression” I interviewed Jonathan Rottenberg about his new book, “The Depths”, which offers valuable insights on ways to help individuals pull out of depression.
One of Rottenberg’s observations is that early improvers from depression tend to “do the right things” as early as possible. These include: remaining physically active, staying socially connected, getting enough sleep, reducing screen time, eating nutritious foods, and achieving small daily goals.
If you’d like to read more on this topic, check out my Psychology Today blog posts: