Each year, about 1% to 6% of children and teenagers develop major depression. This mood disorder not only interferes with school achievement and relationships, but also increases the risk of suicide (the third leading cause of death in adolescents). Depression early in life also raises the risk of developing more severe and chronic symptoms later in life.
Parents (and the youths themselves) have a right to be nervous about the risks of treatment. But the suffering and risk connected to depression itself is significant. Families need information about this disorder, including who is most at risk, to make wise decisions about treatment.
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Risk Factors for Depression
Three risk factors make adolescents more vulnerable to developing major depression.
- Depressed parents. Children whose parents currently have depression or who have experienced it in the past are three to four times as likely as other youths to develop depression themselves. This most likely reflects the fact that depression has a genetic component that can be passed from parents to children. But it may also represent the impact of living with a depressed parent.
- Depressive symptoms. Adolescents who have one or more depressive symptoms — but who do not yet meet the criteria described by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) — are two to three times as likely as other youths to eventually meet criteria for major depression.
Recognizing the symptoms can be challenging, however, because depression often shows up differently in youths than in adults. The Treatment for Adolescents with Depression Study (a clinical trial sponsored by the National Institute of Mental Health) concluded that of 439 youths ages 12 to 17 with major depression, only 20% showed typical symptoms of depression. More often, depressed youths are irritable, have behavioral problems, refuse to go to school or have academic difficulties (such as failing courses). They also may complain of aches and pains and other bodily symptoms that have no apparent physical cause.
- Prior depression. If a child or teenager has previously been diagnosed with depression, he or she has a high chance of developing the disorder again. Studies suggest that 50% to 70% of adolescents who are treated successfully for depression will experience a relapse of symptoms within five years of initial diagnosis.
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Reducing the Risks
Depression prevention programs are likely to work best when targeted to youths most at risk. Most programs include principles of cognitive behavioral therapy (CBT), such as problem solving and challenging pessimistic thinking.
In one randomized controlled trial reported in 2009, investigators at four U.S. sites recruited 316 adolescents, ages 13 to 17. These youths were considered at risk for depression. They either had some symptoms of depression, had a past history of depression or their parents had a history of depression. They were randomly assigned either to group CBT or to usual care in the community. Participants who received CBT participated in eight weekly 90-minute group sessions, followed by six monthly CBT maintenance sessions. The researchers held meetings with parents on the first and eighth weeks to update them about the treatment.
Within a year after the study began, 21% of youths who participated in group CBT had experienced a depressive episode, compared with 33% of youths who were randomized to usual care. The intervention was not more effective than usual care, however, when youths at risk for depression were living with parents who were experiencing depression themselves.
Although research provides support for CBT, this type of intensive treatment may be difficult to find in the community. Fortunately, other research suggests that relatively simple strategies may also be effective.
- Using data from the National Longitudinal Study of Adolescent Health, investigators found that 4% (148 of 3,795) of the adolescents who reported participating in a sport five or more times a week were depressed, compared with 10% of those who did not participate in sports at all (387 of 3,922). Risk of depression decreased in a linear fashion as sports participation increased.
- Another study, involving a nationally representative sample of 15,659 youths in grades 7 to 12, found that youths who went to bed after midnight were more likely to develop depression than those who went to bed by 10 p.m.
Although the results are intriguing, neither of these studies can prove that lack of sleep or exercise causes depression. It may be that children suffering from depressed mood are less likely to sleep well or participate in sports. Additional research is necessary before clinicians can say for sure whether encouraging children to engage in physical activity and to get enough sleep will help prevent depression.
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How Treatment Can Help
It is easy for health care providers to recommend more exercise and more sleep for adolescents. In fact, it is probably great advice at any age. But it is hard to motivate an adolescent who is already feeling down. If encouragement doesn’t help, it probably makes sense to pursue treatment.
Fortunately, there is good evidence that standard treatments can provide significant relief. Milder forms of depression often respond to supportive interventions, such as a short course of psychotherapy. For those adolescents who suffer with more severe depression, psychotherapy or antidepressant medication is effective. The most effective approach is a combination of the two.
And common sense dictates that the earlier you can help an adolescent get treatment, the less he or she will be at risk.
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Michael Craig Miller, M.D. is editor-in-chief of the Harvard Mental Health Letter and an assistant professor of psychiatry at Harvard Medical School. Dr. Miller has an active clinical practice and has been on staff at Beth Israel Deaconess Medical Center for more than 25 years.