Adolescence is a tough time for many – and a new review has produced some startling figures to describe just how tough. Approximately one in five teenagers has a psychiatric disorder. Adolescence signals an increase for rates of depression, panic disorder, agoraphobia, and substance abuse disorder. Moreover, a proportion of the disorders that appear in adolescence peak at, or are limited to, this period. Substance abuse tends to fall dramatically once young people reach their mid-twenties, for instance.

But it’s not all bad news for teenagers. As young people move out of childhood into their teenage years, other anxiety disorders – specifically, separation anxiety and social phobias, as well as attention-deficit disorders – begin to decrease and continue to do so into adulthood.

Although the concept of “adolescence” varies across cultures, developmental studies suggest that negotiating the years between approximately 12 and 19 presents particular challenges, distinct from those faced in childhood or adulthood. We might expect rates of emotional and behavioral disorders to peak during this period, between “the relative calm of childhood and adulthood.” The new review published in Child Psychology and Psychiatry, however, proposes “a more nuanced picture.”

The review, conducted by a team of researchers from Duke University Medical Center, looked at studies from the last 15 years that examined rates of psychiatric disorder in adolescent populations. The authors focus on how the rates of disorder change as young people move into and out of adolescence and whether particular disorders persist over time or are limited to the developmental period.

Prevention efforts during childhood and adolescence take on new importance in light of the finding that “more than three quarters of young adults with disorders first had a diagnosis between the ages of 11 and 18 years.” Many of the disorders that first appear in adolescence reoccur later in life (called homotypic prediction); for example, childhood depression strongly predicts adult depression. Others lead to different forms of disturbance in adulthood (called heterotypic prediction); for example, adolescent conduct problems tend to precede anxiety and depression in adulthood as well as substance abuse.

Twenty-two longitudinal and cross-sectional studies were included in the review, including many covered previously by Prevention Action, such as the Great Smoky Mountains Study; the Dunedin study; the British Child and Adolescent Mental Health Survey; and the E-Risk twin study. The authors decided to exclude the many studies that report symptom scores, and to use only studies that make psychiatric diagnoses.

Even so, reviews of this sort are very difficult to conduct, as the authors acknowledge, and it is difficult to get precise results. For instance, although the average rate of any adolescent psychiatric disorder in the studies reviewed was 21.8%, the individual study results ranged from 6% to more than 40%. There are several reasons for caution: studies vary widely in the rates of disorders they find; many studies do not report confidence intervals, so it’s not possible to test the size of an increase or decrease; and the data come from countries around the world, while the experience of adolescence may be very different in different places.

Charting these trends is only the first step. Beginning to identify and understand the causal factors that lead to them is the next. For example, are the increases seen in certain disorders during adolescence the result of particular biological changes during puberty? Could particular social contexts be responsible for the rise and fall of mental illness in young people? Studies that test these predictors of disturbance, and their interactions, across different developmental stages are now needed.

Source:
Costello, E.J., Copeland, W. and Angold, A. (2011). Trends in psychopathology across the adolescent years: What changes when children become adolescents, and when adolescents become adults? Journal of Child Psychology and Psychiatry, 52 (10), 1015-1025.