AN ETIOLOGIC MODEL OF NONMELANCHOLIC DEPRESSION - STUDY DESIGN AND VALIDITY OF THE MEASURES

Objective: The aim of this paper is to describe an approach to sub-typ ing nonmelancholic depression and to determine which raters from a var iety of backgrounds provided the most valid information on study varia bles. Method: A sample of non-melancholic depressed patients is descri bed. Multiple raters (i.e. patients, psychiatrists, referrers and corr oborative witnesses) completed measures of the patient's trait anxiety levels, severity of recent life event stressors and personality funct ioning. Results: The study and representative data are reported. Congr uence between several measures employed indicated that psychiatrist ra ting of disordered personality was superior to corroborative witness r eport. Assessment of anxiety traits indicated reasonable agreement bet ween referrers and corroborative witnesses but poor agreement between those ratings and interview-elicited ratings. There were also discrepa ncies in quantifying 'severity' of life event stress, with patients an d their corroborative witnesses rating such events as more severe than either the interviewing psychiatrist or psychiatrists involved in con sensus rating sessions. Importantly, the psychiatrists' capacity to qu antify the relative contribution of disordered personality, anxiety an d life-event stress to the particular depressive episode was supported , Conclusions: Results indicate some of the difficulties in operationa lising determinants that may contribute to and sub-type the non-melanc holic depressions, and demonstrate the advantages of using a range of rating strategies and raters. In this study, psychiatrist-generated ju dgements are clearly favoured, although the advantages of also assessi ng trait anxiety and life-event stress impact by self-report strategie s are conceded. Some techniques for estimating the contribution of dis ordered personality function, anxiety and life-event stress are offere d for both their research and their clinical utility.