New findings from a study supported by the National Institute on Drug Abuse (NIDA), National Institutes of Health, show that girls and boys who exhibit high levels of risky behaviors have similar chances of developing symptoms of depression. However, gender differences become apparent with low and moderate levels of risky behaviors with girls being significantly more likely than boys to experience symptoms of depression. The study, which incorporates data from almost 19,000 teens, is published in the May 15, 2006 issue of the Archives of Women's Mental Health.
"The burden of illness associated with depression during adolescence is considerable, and psychosocial problems - including substance abuse - are associated with depressive disorders in teens," says NIDA Director Dr. Nora D. Volkow. "The findings from this study create a more complete picture of commonalities and differences of the risk of depression among boys and girls who engage in risky behaviors, and provide information for healthcare providers to consider as they screen, evaluate, and treat their young patients."
Symptoms of depression include loss of appetite, feeling blue, loss of interest in things that used to be of interest, being bothered by things that previously were not bothersome, and not feeling hopeful about the future.
Dr. Martha Waller, of the Pacific Institute for Research and Evaluation, and her colleagues provided new findings from teen interviews conducted as part of the National Longitudinal Study of Adolescent Health in 1995. The researchers clustered the teens into 16 groups according to their behaviors and correlated these behaviors with symptoms of depression. Groups included abstainers, who refrained from engaging in sexual activity and from using alcohol, tobacco, or other drugs; teens who engaged in low and moderate risk behaviors, such as experimenting with substance abuse or sex; and teens who engaged in high-risk behaviors, such as exchanging sex for drugs or money or abuse of intravenous drugs.
"Differences in symptoms of depression between girls and boys were guided by risk behaviors," says Dr. Waller. "Among abstainers, there were no differences between girls and boys in their likelihood of having symptoms of depression."
When abstaining girls were compared with risk-taking girls, the researchers observed that any risk activity, no matter how modest in degree, was associated with an increased risk of symptoms of depression. For example, girls who experimented with drugs and girls who experimented with tobacco and alcohol were more than twice as likely to have symptoms of depression as girls who abstained completely. Girls who experimented with sex were almost four times as likely to have such symptoms, while girls who used intravenous drugs were almost 18 times as likely to have symptoms of depression as girls who abstained completely.
Among boys, most, but not all risk profiles were associated with a greater likelihood of such symptoms, compared to abstainers. Boys who drank alcohol and boys who were binge drinkers were about two-and-one-half times as likely to experience symptoms of depression, while those who abused intravenous drugs were about six times as likely to have symptoms of depression as boys who abstained completely.
For most of the high-risk behaviors profiled there were also no significant gender differences in symptoms of depression. However, for one - exchanging sex for money or drugs - girls were seven times more likely than boys to report such symptoms. Among teens who engaged in low and moderate risk behaviors, girls were significantly more likely than boys to report symptoms of depression.
"Although it has not been shown that these behaviors trigger depression, it may be that screening for substance abuse and other behaviors in teens may provide enough information to the health care provider to also warrant screening for depression, particularly for girls," says Dr. Waller. "Both substance abuse and sexual activity may alter a girl's social context, which could induce stress and/or change self-perceptions, both of which could contribute to depression. In addition, there may be differences in how girls and boys physically respond to substance abuse that help explain the gender differences."
Because girls who exhibited low and moderate risk behaviors were observed to be at greater risk for depression than boys, the scientists suggest that future research should examine the characteristics of these groups to determine the mechanisms underlying this difference.
"There are significant changes in the brain during adolescence and there is growing interest in understanding how substance abuse may change brain structure and chemistry, and in turn, cognition and emotion," says Dr. Volkow. "Future research will investigate more closely the roles of risky behaviors and the influence of gender in the development of adolescent depression."
Reference: Martha W. Waller, Denise Dion Hallfors, Carolyn Tucker Halpern, Bonita Iritani, Carol A. Ford, and Guang Guo, Gender Differences in Associations Between Depressive Symptoms and Patterns of Substance Use and Risky Sexual Behavior Among a Nationally Representative Sample of U.S. Adolescents, Archives of Women's Mental Health, Vol. 9, No. 3, pp. 139-150, 2006.