A dimensional approach to personality in atypical depression Kevin K. Chopra a, T , R. Michael Bagby b , Susan Dickens c , Sidney H. Kennedy d , Arun Ravindran b , Robert D. Levitan b a Department of Psychiatry, University of Toronto, c/o CAMH Room 1121, 250 College Street, Toronto, Ontario, Canada M5T 1R8 b Mood and Anxiety Program, Centre for Addiction and Mental Health (CAMH), and Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada c Mood and Anxiety Division, CAMH, Toronto, Ontario, Canada d Department of Psychiatry, University Health Network, University of Toronto, Toronto, Ontario, Canada Received 18 August 2004; received in revised form 26 November 2004; accepted 11 February 2005 Abstract The current study addresses the relationship of personality and atypical depression using the Five-Factor Model (FFM), a dimensional approach to personality. The aim of the study was to help clarify which personality traits are more characteristic of atypical depression than of other depressive subtypes. Outpatients (n = 160) with non-psychotic major depression were characterized as having atypical (n = 26), or non-atypical depression (n =134) based on DSM-IV criteria. To limit the effect of state depression, personality was assessed after subjects received a minimum of 14 weeks of antidepressant treatment. The Revised NEO Personality Inventory, which generates data based on the FFM, was the primary assessment measure. Post- treatment, relative to the non-atypical comparison group, the atypical group had significantly higher scores on the dimension of Neuroticism, the facets of Impulsivity and Anger–Hostility, and a significantly lower score on the facet of Deliberation. In sum, the FFM provides a new understanding of which unique personality characteristics may be associated with atypical depression. D 2005 Elsevier Ireland Ltd. All rights reserved. Keywords: Five-Factor Model; NEO Personality Inventory; Neuroticism; Impulsivity; Anger–Hostility; Deliberation 1. Introduction The conceptual understanding of reversed vegeta- tive symptoms (increased appetite and hypersomnia) coexisting with specific personality features has evolved over several decades. Initially, atypical depression described patients who exhibited reversed vegetative symptoms and hysterical personality traits, thus depicting them as over-reactive, anxious, and somatically preoccupied (West and Dally, 1959; Liebowitz and Klein, 1979). More recent literature has suggested associations of atypical depression to interpersonal sensitivity, and to Cluster B (dramatic/ emotional) as well as Cluster C (anxious/fearful) 0165-1781/$ - see front matter D 2005 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.psychres.2005.02.002 T Corresponding author. Tel.: +1 416 535 8501x4238; fax: +1 416 979 6821. E-mail address: kevin _ chopra@camh.net (K.K. Chopra). Psychiatry Research 134 (2005) 161 – 167 www.elsevier.com/locate/psychres