Figure 2 displays the proportion of adolescents affected by one or more broad classes of disorder among those with at least one DSM-IV disorder. A small majority of affected adolescents (61%) met criteria for disorders from one class only, with anxiety disorders being the most frequent condition to occur alone (35%) and smaller proportions having only behavior (14%), mood disorders (6%), or substance use disorders (6%). About one-quarter (25%) of adolescents affected by at least one class of disorder also met criteria for a disorder from one additional class, 11.0% were affected by three classes of disorders and 3% were affected by four classes of disorder.
