An international study of the relation between somatic symptoms and depression

Background Patients with depression, particularly those seen by primary car e physicians, may report somatic symptoms, such as headache, constipation, weakness, or back pain. Some previous studies have suggested that patients in non-Western countries are more likely to report somatic symptoms than ar e patients in Western countries. Methods We used data from the World Health Organization's study of psycholo gical problems in general health care to examine the relation between somat ic symptoms and depression. The study, conducted in 1991 and 1992, screened 25,916 patients at 15 primary care centers in 14 countries on 5 continents . A total of 5447 of the patients underwent a structured assessment of depr essive and somatoform disorders. Results A total of 1146 patients (weighted prevalence, 10.1 percent) met th e criteria for major depression. The range of patients with depression who reported only somatic symptoms was 45 to 95 percent (overall prevalence, 69 percent; P=0.002 for the comparison among centers). A somatic presentation was more common at centers where patients lacked an ongoing relationship w ith a primary care physician than at centers where most patients had a pers onal physician (odds ratio, 1.8; 95 percent confidence interval, 1.2 to 2.7 ). Half the depressed patients reported multiple unexplained somatic sympto ms, and 11 percent denied psychological symptoms of depression on direct qu estioning. Neither of these proportions varied significantly among the cent ers. Although the overall prevalence of depressive symptoms varied markedly among the centers, the frequencies of psychological and physical symptoms were similar. Conclusions Somatic symptoms of depression are common in many countries, bu t their frequency varies depending on how somatization is defined. There is substantial variation in how frequently patients with depression present w ith strictly somatic symptoms. In part, this variation may reflect characte ristics of physicians and health care systems, as well as cultural differen ces among patients. (N Engl J Med 1999;341:1329-35.) (C) 1999, Massachusett s Medical Society.