Use of the five-factory inventory in characterizing patients with major depressive disorder

Research on personality traits has suggested an association between depress ion and certain personality traits, such as neuroticism and extraversion. C osta and McCrae's five-factor personality inventory (NEO) has been shown to measure personality traits in a nonclinical population, but its use has no t been fully explored in clinical populations. This study aims to compare N EO results in a sample of depressed outpatients with published test norms, and determine if different levels of neuroticism and extraversion are assoc iated with differences in certain psychosocial and clinical characteristics . Seventy-six depressed outpatients participating in antidepressant clinica l trials completed this self-report questionnaire before beginning pharmaco logical treatment. Diagnosis of major depressive disorder (MDD) was made us ing the Structured Clinical Interview for DSM-III-R or DSM-IV and the sever ity of depression was measured with the 17-item Hamilton Depression Rating Scale (HAM-D). The three analyses conducted were as follows: (1) NEO factor scores were compared with published normative means; (2) three groups, bas ed on level of neuroticism, were compared on certain psychosocial and clini cal characteristics; and (3) three groups, based on level of extraversion, were compared on the same psychosocial and clinical characteristics. Both t he males and females obtained T score values for the Neuroticism Scale 1.5 SD above the mean, for the Extraversion Scale 1.5 SD below the mean, and fo r the Conscientiousness Scale 1.5 SD below the mean. No significant differe nces were found between subjects with different levels of neuroticism and e xtraversion, although a trend did exist indicating a positive relationship between neuroticism and severity of depression. Depressed outpatients exper ience frequent negative affects, have irrational thought processes, cope wi th stress poorly, have difficulty controlling impulses, prefer to be alone, and have difficulty carrying out tasks. Future studies should examine how such personality factors affect response to treatment and course of illness . Copyright (C) 2001 by W.B. Saunders Company.