The development of a six-item daily self-report measure assessing identified depressive domains

Background: There is debate as to whether any anti-depressant strategy acts more rapidly than any other, while ‘improvement’ in overall depression severity reflects a summation of individual domains that may individually show differing trajectories. We developed a brief self-report measure of depression’s constituent constructs to allow such issues to be examined. Methods: A 25-item measure was prepared and completed daily by depressed patients until they had evidenced distinct improvement. Results: Factor analyses favoured a six-factor structure, with constructs labelled depression, irritability, brooding, poor concentration, insomnia and anxiety. Scores on those constructs were differentially associated with overall depression severity as measured on the clinician-rated Hamilton measure, arguing for their potential utility. Limitations: The original data set was small while the measure’s utility will only emerge in application studies. Conclusions: The six-item measure is appended and several possible application studies noted. In particular, we favour its evaluation in studies examining the impact and time to onset of differing antidepressant strategies on differing depressive sub-types.