Depression in adolescence is even more common than previous estimates indicated and girls experience more depression than boys, according to research from Children's Hospital of Pittsburgh of UPMC, the RAND Corporation, and the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

The research, published in Translational Psychiatry, shows that the proportion of adolescents who experience depression is higher than previous studies have reported; 36 percent for girls and 14 percent for boys. These depressive episodes are associated with poor outcomes - problems with school, relationships, suicide attempts - even with depression that started recently.

"Since we found that many more adolescents go through periods of depression than previously thought, it is important that we find ways to identify those individuals most likely to suffer the most severe consequences to make sure they are prioritized for treatment," said Joshua Breslau, Ph.D., Sc.D., researcher at the RAND Corporation and lead author of the study.

The researchers examined data from 2009 to 2014 collected annually from nationally representative samples of adolescents ages 12 to 17. They noted gender differences in the incidence of depression by age and compared recent first-onset and persistent depression with respect to impairment, suicide attempts, conduct problems and academic functioning.

Adolescent depression is characterized by extended periods of low mood or feeling unable to enjoy normally pleasurable activities. Other common symptoms include insomnia, irritability, weight gain or loss, and feelings of guilt or worthlessness. This national survey uses measures consistent with a diagnosis of depression.

"Our study reveals that depression is far too common and is associated with serious problems in school and at home for adolescents," said senior author Elizabeth Miller, M.D., director, Division of Adolescent and Young Adult Medicine, Children's Hospital. "While we still have much work to do to understand why so many more girls experience depression than boys, adults who work with young people - especially clinicians, school teachers and counselors - should recognize adolescent depression and connect young people who display signs of depression to appropriate mental health services. Don't wait and expect things to get better without help."

The analysis also found that this gender difference starts earlier than previous studies indicated; at least by age 11, if not younger, suggesting that factors in childhood also may contribute to the gender difference.

"Clinicians and those who work with children and youth in schools and afterschool environments need to be aware of the seriousness of any signs of adolescent depression and connect young people to treatment early," added Dr. Miller.

This research was supported by a grant from the National Institute on Minority Health and Health Disparities (R01MD010274) and by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

Article: Sex differences in recent first-onset depression in an epidemiological sample of adolescents, J Breslau, S E Gilman, B D Stein, T Ruder, T Gmelin and E Miller, Translational Psychiatry, doi: 10.1038/tp.2017.105, published online 30 May 2017.