One-year stability, change and incidence in anxiety symptoms among early adolescents in the general population.

To examine prospectively the stability, changes, and incidence in DSM-IV-related anxiety symptom clusters in a community sample of adolescents. On two occasions, 1 year apart, 946 Norwegian adolescents aged 13-16 years completed the SCARED, a 41-item multidimensional anxiety self-report scale that measures the levels of five principal DSM-IV-related anxiety symptom clusters. Seventy-three percent of the adolescents participated in the study at baseline, and only 7 % were lost to follow-up. Both sexes in all age cohorts, except girls aged 14-15 years, showed the same 1-year developmental pattern of stable scores, or small reductions in the total anxiety score, for all DSM-IV-related anxiety symptom clusters. Adolescents defined as "high anxiety scorers" showed a girl:boy ratio of 4:1. Whereas approximately half these students remained high scorers at the 1-year follow-up, the same proportion returned to normal anxiety levels. The 1-year incidence of high-level anxiety was 8.2 % for the whole sample, 12.6 % for the girls and 3.4 % for the boys. These results underscore the need for improved identification of adolescents in the general population with stable high anxiety levels, as opposed to those with transient high anxiety. The normative findings of this study also provide reference data with which to evaluate individual changes in clinical practice and the results of efficacy trials, including 1-year follow-up evaluations.