Of the adolescents who met criteria for MDD, the mean number of symptoms was 6.9 (SD = 1.2). In 38.3% of the MDD episodes, 5 or 6 symptoms were present; 7 or 8 symptoms were presented in 49.5% of the episodes, and all 9 symptoms were present in 12.2% of the episodes. As can be seen, of the two core symptoms of MDD, depressed mood is more prevalent than anhedonia in depressed adolescents (97.7% vs. 77.3%); anhedonia rarely exists in the absence of depressed mood (2.3% of MDD cases), and in 75.0% of MDD cases both core symptoms are present.
Community Versus Clinic Cases
We also examined whether community-based MDD cases are phenomenologically similar to MDD cases in treatment settings. From an epidemiologic perspective, it is important to know whether treated cases differ from cases identified in community surveys. To answer this question, data from the OADP study were compared with results from six published studies of adolescent patients (inpatients and outpatients) who had received the diagnosis of MDD. The proportion of OADP participants with MDD who met each of the nine DSM-III-R criteria is shown in the first column of Table 2. In the second column, we have listed the mean percentage of depressed adolescents meeting each criterion across the six patient studies, with a range of values provided in the third column.