Subsyndromal depression in adolescents after a brief psychotherapy trial: course and outcome.

INTRODUCTION: Subsyndromal depression has been associated with an increased risk of the development of major depressive disorder (MDD). Since treatment trials of adolescent MDD often result in subsyndromal depression as the outcome, the long-term course of these youth would be useful to understand.
METHODS: 107 adolescents with MDD participated in a clinical psychotherapy trial, of whom 99 were followed up for two years after acute treatment. Those with subsyndromal depression (2-3 symptoms) at the end of acute treatment were compared to those who were well (< or =1 symptom) and those who were still depressed (> or =4 symptoms) on presentation at intake, the end of treatment, and over the two-year follow-up.
RESULTS: Of the 99 youth, at the end of acute treatment 26 were well, 18 were subsyndromal, and 55 were still depressed. A substantial proportion of the subsyndromally depressed youth were functionally impaired (38%), and showed a protracted time to recovery. The risk of recurrence was similar to those who were without depression at the end of acute treatment (46% vs. 44%). Recurrence was predicted by depressive symptom severity and family difficulties at the end of acute treatment. LIMITATIONS: A large proportion of the subsyndromal groups received open treatment that may have altered their course. Also, this was a referred sample, rather than an epidemiological one.
CONCLUSIONS: In clinical samples treated with psychotherapy, subsyndromal depression poses a significant risk for functional impairment and protracted recovery. Depressive recurrence may be prevented by targeting reduction of symptom severity and of family difficulties.