Validity of K-SADS-PL (Schedule for Affective Disorders and Schizophrenia for School-Age Children--Present and Lifetime Version) depression diagnoses in an adolescent clinical population.

Background: Validity studies of the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS) interview are modest in number given the international acceptance and extensive use of this instrument in epidemiological and treatment research. The results are somewhat mixed and limited, particularly for adolescent depression.

Aims: The objective of this study was to assess the convergent-divergent validity of the screen criteria and depression diagnoses (major depressive episode) generated with the diagnostic interview Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL).

Methods: Participants were 86 consecutively admitted inpatients aged 12-17 years and their parents. Both convergent and divergent validity of the depression diagnoses were assessed against 11 standard self-report or parent-report rating scales, all of which had been translated, adapted and in most cases validated in Iceland. A total of 25 subscales were included in calculations.

Results: Convergent validity was confirmed, with adolescents who screened positive or met criteria for major depressive episode scoring higher than other patients did on scales assessing depressive symptoms. However, divergent validity was only partially supported in this highly comorbid inpatient sample. Severity based on number of diagnostic criteria met had a generally substantial correlation with the rating scales.

Conclusions: This study provides a substantial additional amount of convergent-divergent validity data related to this extensively used diagnostic instrument.