Specific Characteristics of the Pain/Depression Association in the General Population

Objective: To evaluate how the presence of a chronic painful physical condition (CPPC) lasting6 months or more influences the frequency and severity of depressive symptoms in subjects with majordepressive disorder (MDD). Method: Random samples of 18,980 subjects aged between 15 and100 years who were representative of the general population of 5 European countries (the UnitedKingdom, Germany, Italy, Portugal, and Spain) were interviewed by telephone between 1994 and1999. Subjects answered a series of questions that allowed positive and differential diagnosis ofDSM-IV mental disorders. The questionnaire also included a series of questions about painful physicalconditions, medical treatment, consultations, and hospitalizations for medical conditions and a listof diseases. Results: A total of 4% (95% CI = 3.7% to 4.3%) of the sample had MDD at the time of theinterview. Nearly half of subjects with MDD (43.4%) also reported having a CPPC. Compared withMDD subjects without chronic pain, MDD subjects with a CPPC had a longer duration of depressivesymptoms (7 months longer) and were more likely to report severe fatigue (OR = 5.4), insomnianearly 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 increasedthe severity of physical symptoms of depression (fatigue, insomnia, psychomotor retardation, weightgain). Moreover, CPPCs affected the duration of depressive episodes and their recurrence. Physiciansshould consider CPPCs as a major factor in the expression and evolution of MDD. They must rememberthat MDD patients tend to amplify physical symptoms, to the detriment of their depressivesymptomatology.