Objective: This study investigated the prevalence and changing trends of mental disorders and the effects of gender and urbanization among adolescents in Taiwan.
Method: A random sample of seventh-grade students (N=1,070) was recruited from one urban and one rural junior high school in which 1,051 (98.2%) and 1,035 (96.7%) were reassessed in the second and third years, respectively. A two-stage case identification was conducted by mental health professionals with the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Epidemiologic Version, supplemented by information from the Child Behavior Checklist.
Results: The weighted 3-month prevalence rates across the 3 consecutive years for overall psychiatric disorders were 20.3%, 22.7%, and 14.8%, respectively. The most prevalent psychiatric condition was attention deficit hyperactivity disorder (ADHD) in the first 2 years and substance use disorders in the third. During the 3 years, the rates for ADHD, specific phobia, and social phobia decreased, and the rates for major depression and substance use disorders, conversely, increased. Although conduct disorder, ADHD, and substance use disorders were more prevalent among boys, the rates for major depression, social phobia, specific phobia, and adjustment disorder were higher among girls. Rural adolescents had higher rates of conduct disorder, oppositional defiant disorder, and substance use disorders than their urban counterparts.
Conclusions: Our findings are similar to those of previous studies among adolescents in prevalence rates, changing trends of most mental disorders, and gender effects. The differential changing trends in various diagnostic groups may imply the importance of specific measures for prevention during adolescence.