Teens With Insomnia at Double the Risk for Major Depression, Study Finds
Thirty percent to 40 percent of adults in the U.S. report symptoms of insomnia each year, the National Sleep Foundation reports. Ten to 15 percent of adults report symptoms of chronic insomnia, a particularly disruptive problem that produces recurring sleep disturbances for longer than half a year. About 14 percent of U.S. teenagers develop at least one symptom of insomnia in a given year, according to the authors of a study published in 2008 in the journal SLEEP. In addition to trouble falling or staying asleep, examples of potential symptoms include sleep that fails to restore daytime energy levels and excessive daytime sleepiness or daytime fatigue. Roughly 5 percent of teenagers develop enough insomnia-related symptoms to qualify for a diagnosis of insomnia disorder.
Some adults and teens develop what’s known as primary insomnia, a form of the condition that has no identified cause. Others develop secondary insomnia, which occurs as a consequence of things such as medication side effects or certain physical ailments. Prior to 2013, the American Psychiatric Association (APA)—which sets the guidelines used for diagnosing mental health problems—only allowed doctors to make mental health diagnoses for cases of primary insomnia. However, doctors can now diagnose insomnia disorder in people affected by either primary insomnia or secondary insomnia. In order to receive an insomnia disorder diagnosis, an affected individual must have insomnia symptoms severe enough to impair his or her ability to function adequately in everyday life.
Link Between Insomnia and Depression in Adults
There is considerable overlap between the symptoms of insomnia and depression. Examples of the symptoms that can appear in association with either disorder include irritability, a drop in motivation and/or physical energy, concentration problems, mood disturbance and inadequate or nonrestorative sleep. In a study and study review published in 2011 in the journal Neuropsychiatric Disease and Treatment, researchers from Australia’s RMIT University examined the connections between insomnia and depression in adult populations. These researchers concluded that 10 percent to 20 percent of adults diagnosed with insomnia disorder also have enough depression symptoms to meet the standards for diagnosing major depression or some other depressive disorder. At the same time, roughly 60 percent of all adults diagnosed with major depression or some other form of depression also have enough insomnia symptoms for an insomnia disorder diagnosis.
Findings in Teenagers
In the study published in the Journal of Affective Disorders, researchers from the University of Texas Health Science Center assessed the connections between insomnia and depression among 3,134 children between the ages of 11 and 17. This assessment included three levels of insomnia: the presence of any single insomnia symptom, the combined presence of insomnia symptoms and the impairment needed to diagnose insomnia disorder, and the presence of insomnia disorder without the coexisting conditions (such as substance use disorder, anxiety disorders or mood disorders) that commonly appear in insomniac individuals. The assessment also included two levels of depression: the presence of any single depression symptom and the presence of enough symptoms to meet the criteria for diagnosing major depression.
After reviewing their findings, the researchers concluded that insomnia in teenagers is more closely associated with the presence of major depression than with isolated depression symptoms. Teenagers with isolated insomnia symptoms experience a roughly 100 percent increase in their chances of developing major depression, while teenagers with diagnosable insomnia disorder experience anywhere from a 100 percent to 200 percent increase in their major depression risks. Looking from the other direction, the researchers concluded that teenagers diagnosed with major depression experience a 100 percent to 200 percent increase in their chances of developing isolated insomnia symptoms and 100 percent increase in their chances of developing diagnosable insomnia disorder.
Despite the overlap between major depression, isolated insomnia symptoms and insomnia disorder, no one knows for sure if major depression actually triggers insomnia-related problems, or if insomnia-related problems actually trigger major depression, the authors of the study in Neuropsychiatric Disease and Treatment explain. The authors of the study in the Journal of Affective Disorders believe that they are the first researchers to investigate the overlapping effects of insomnia and depression in teenagers. As a cautionary note, they emphasize the fact that their work relies on self-reported insomnia symptoms, not objective insomnia testing.