Major depressive disorder: afternoon and evening diurnal mood variation is common

ED FROM Morris DW, Rush AJ, Jain S, et al. Diurnal mood variation in outpatients with major depressive disorder: implications for DSM-V from an analysis of the sequenced treatment alternatives to relieve depression study data. J Clin Psychiatry 2007;68:1339–47. Correspondence to: Madhukar H Trivedi, MD, Mood Disorders Program & Clinic, Department of Psychiatry, University of Texas Southwestern Medical Center, Exchange Park Express, American General Tower, 6363 Forest Park Road, Suite 13.354, Dallas, Texas, USA; madhukar.trivedi@utsouthwestern.edu Source of funding: National Institute of Mental Health. C O M M EN TA R Y D iurnal mood variation (DMV), typically understood as morning worsening of mood, is a core element of the melancholic/endogenous/ somatic subtype of major depressive disorder as characterised in DSM and ICD. However, research has been sparse, and the study by Morris and colleagues constitutes a substantial advance in the characterisation of DMV. They found support for the assumption of a link between DMV and a number of other symptoms typically described as melancholic (for example, decreased libido and psychomotor slowing). DMV was found unrelated to symptoms of atypical or anxious depression. The presence of diurnal variation in mood was marked –21.6% of the sample reported DMV not attributable to exogenous factors. However, there are three findings that challenge the common definition of DMV as a melancholic symptom. First, morning worsening pattern made up only 30.8% of the DMV group, while 47.0% of those reporting DMV described evening worsening of mood (a pattern typically associated with neurotic depression). Second, the association between DMV and other melancholic features was stronger when all forms of DMV (morning, afternoon and evening worsening) were aggregated than when classical morning worsening was investigated alone. Finally, there was little difference clinically or demographically between patients reporting the various forms of DMV. These are very interesting data. On the one hand, DMV appears to be relatively common (about the same prevalence as melancholic major depressive disorder) and specifically linked to other melancholic symptoms. On the other, the phenomenology of DMV appears to be not as we had assumed. The authors conclude that the definition of melancholia may need revision to include all forms of DMV. More sceptically, the data can be viewed as a challenge to the latent construct of melancholia, for which classical DMV is a defining feature. As acknowledged by the authors, the findings are not definitive. Effect sizes were small to moderate and there was a failure to control for overall level of depression. Structural equation modelling would have permitted clearer conclusions as well as consideration of more recent descriptive schemes. Nonetheless, the paper is significant in suggesting that if DMV means anything in psychopathology, it means diurnal mood variation of various forms. Greg Murray, PhD MAPS Senior Lecturer and Clinical Psychologist Coordinator, MPsych (Clinical Psychology), Swinburne University of Technology, Australia Competing interests: None declared. 1. Watson D. Rethinking the mood and anxiety disorders: a quantitative hierarchical model for DSM-V. J Abnorm Psychol 2005;114:522–36. Prevalence EBMH May 2008 Vol 11 No 2 59