© COPYRIGHT 2004 PHYSICIANS POSTGRADUATE PRESS, I NC. © COPYRIGHT 2004 PHYSICIANS POSTGRADUATE PRESS, I NC. 5 J Clin Psychiatry 2004;65 (suppl 12) Pain/Depression Association in the General Population t is estimated that in 2020, major depressive disorder (MDD) will be the second cause of disability in indus- Specific Characteristics of the Pain/Depression Association in the General Population Maurice M. Ohayon, M.D., D.Sc., Ph.D. Objective: To evaluate how the presence of a chronic painful physical condition (CPPC) lasting 6 months or more influences the frequency and severity of depressive symptoms in subjects with ma- jor depressive disorder (MDD). Method: Random samples of 18,980 subjects aged between 15 and 100 years who were representative of the general population of 5 European countries (the United Kingdom, Germany, Italy, Portugal, and Spain) were interviewed by telephone between 1994 and 1999. Subjects answered a series of questions that allowed positive and differential diagnosis of DSM-IV mental disorders. The questionnaire also included a series of questions about painful physi- cal conditions, medical treatment, consultations, and hospitalizations for medical conditions and a list of diseases. Results: A total of 4% (95% CI = 3.7% to 4.3%) of the sample had MDD at the time of the interview. Nearly half of subjects with MDD (43.4%) also reported having a CPPC. Compared with MDD subjects without chronic pain, MDD subjects with a CPPC had a longer duration of depressive symptoms (7 months longer) and were more likely to report severe fatigue (OR = 5.4), insomnia nearly every night (OR = 3.3), severe psychomotor retardation (OR = 3.3), weight gain (OR = 2.3), severe difficulty concentrating (OR = 1.7), and severe feelings of sadness or depressed mood (OR = 1.8). Conclusion: A CPPC was present in nearly half of subjects with MDD. CPPCs increased the severity of physical symptoms of depression (fatigue, insomnia, psychomotor retardation, weight gain). Moreover, CPPCs affected the duration of depressive episodes and their recurrence. Physicians should consider CPPCs as a major factor in the expression and evolution of MDD. They must re- member that MDD patients tend to amplify physical symptoms, to the detriment of their depressive symptomatology. (J Clin Psychiatry 2004;65[suppl 12]:5–9) From the Stanford Sleep Epidemiology Research Center, School of Medicine, Stanford University, Stanford, Calif. This research was supported by grant 971067 from the Fond de la Recherche en Santé du Quebec (FRSQ), Montreal, Quebec, Canada, and by an unrestricted educational grant from Sanofi-Synthelabo Group, Paris, France. This article is derived from the teleconference “Recognizing the Physical Symptoms of Depression,” which was held March 16, 2004, and supported by an unrestricted educational grant from Eli Lilly and Company. Corresponding author and reprints: Maurice M. Ohayon, M.D., Stanford Sleep Epidemiology Research Center, School of Medicine, Stanford University, 3430 W. Bayshore Rd., Suite 102, Palo Alto, CA 94303 (e-mail: mohayon@stanford.edu). I trialized countries, exceeded only by ischemic heart dis- ease. 1 Most recent epidemiologic studies have estimated the prevalence of MDD to be between 4% and 6% of the United States and western Europe. 2–7 Major depressive disorder comprises several physical symptoms: insomnia, hypersomnia, psychomotor agitation or retardation, changes in appetite or weight, and fatigue. These symptoms are often the only reasons evoked by patients with depressive disorders for seeking medical help: according to the results of an international multicen- ter study, 8 up to 69% of primary care patients identified as having MDD reported only somatic symptoms. Furthermore, subjects with MDD have a 4 times greater risk of suffering from chronic painful physical conditions (CPPCs) than nondepressed individuals 9 and a greater risk of having long-term medical conditions. 10–12 A pitfall in nonpsychiatric settings is limiting the treat- ment to physical symptoms while overlooking other signs of depression. Treating only physical symptoms or only the depressive disorder may adversely affect the course of depression. This study examined how CPPCs lasting at least 6 months influenced the frequency and severity of depres- sive symptoms in subjects from the general population with MDD. 9 My colleagues and I postulated that the pres- ence of a CPPC would impact not only on the frequency but also on the severity of depressive symptoms. We also explored the evolution of depressive illness in subjects with a CPPC in terms of chronicity and relapse because of their impact on treatment.