NONMELANCHOLIC DEPRESSION - THE CONTRIBUTION OF PERSONALITY, ANXIETY AND LIFE EVENTS TO SUBCLASSIFICATION

Background, We sought to develop a clinically useful subtyping system for the non-melancholic depressive disorders, and here we assess one w eighted to central aetiological factors. Methods, We studied 185 patie nts meeting DSM-III-R and/or clinical criteria for non-melancholic dep ression. Data were obtained by self-report, interview of patients and from corroborative witnesses. We developed a set of variables for clas s definition, assessing: (i) 'P', disordered personality as a vulnerab ility factor; (ii) 'A', meeting criteria for a lifetime anxiety disord er or positive on probe questions about trait anxiety characteristics, so assessing anxiety as a vulnerability factor; and (iii) 'L', psychi atrist and consensually-rated life event stress prior to depression on set. Results, A latent class analysis generated a four-class solution for the P-A-L variables. Life event stressors had similar item probabi lities across all four classes, and did not influence the four-class ' P-A' solution when deleted from the analysis, suggesting that life eve nt stress may act more as a general provoking agent, rather than const ituting any distinct 'reactive' or 'situational' depression class. Thr ee classes generated clinically meaningful groupings, reflecting varyi ng contributions of anxiety and disordered personality functioning, an d with evidence of differential outcome over the following 12 months.C onclusions: We suggest that a refined aetiologically-weighted model ma y assist definition of the non-melancholic depressive disorders, and p rovide the logic for exploring the comparative utility of differing tr eatments to identified vulnerability-based classes.