The DSM-IV nosology of chronic pain: a comparison of pain disorder and multiple somatization syndrome.

This study evaluates the classification of pain from the perspective of the DSM-IV system. Of 60 in-patients with long-standing and disabling pain syndromes, 29 with pain disorder (PD) and 31 with pain as part of a multiple somatization syndrome (MSS) were compared before and after a structured cognitive-behavioral treatment. It was hypothesized that MSS patients show more psychological distress, are more severely disabled, and respond less to the treatment. Both groups were similar with respect to sociodemographic status, history of pain symptomatology and comorbidity with DSM-IV mental disorders. The results show that MSS patients had higher levels of affective and sensoric pain sensations as well as more pain-related disabilities. They were also less successful during treatment to reduce their pain-related depression and anxiety. Psychosocial functioning was improved only by PD patients, but remained almost unchanged in the MSS group. However, there were no group differences concerning general depression and hypochondriasis, dysfunctional attitudes towards body and health, and use of pain coping strategies. It is concluded that the DSM-IV distinction between 'pure' pain disorder and syndromes involving pain plus multiple somatoform symptoms cannot generally be confirmed, but further studies of validation are needed.