Reliability of depression and associated clinical symptoms.

Interrater reliability assessments were undertaken for the Hamilton Depression Rating Scale, the Raskin Depression Rating Scale, and the Degree of Mental Illness Scale. Levels of reliability ranged from "poor" to "excellent" and varied as a function of (1) temporality (assessments made at termination of clinical trial more reliable than those made at randomization into treatment) and (2) unit of scoring (factor or total scores more reliable than single-item assessments). The implications of these results may be considered in the context of further studies evaluating the efficacy of treatment interventions on reduction of symptoms of clinical depression.