Sleep disturbances in somatoform pain disorder.

Unlabelled: Patients with chronic somatoform pain often complain about sleep disorders. However, sleep disorder/disturbances are not an integrated part of the somatoform disorders in the DSM-IV and the ICD-10. Sleep is important for recreation. Deprivation of deep sleep stages is experimentally linked to muscle pain. Therefore, sleep disorder may play an important part in the persistence of somatoform pain disorder. The aim of the study was to evaluate the frequency of sleep disorder in patients with somatoform pain disorder and to correlate it with comorbid depression, pain parameters and psychosocial parameters.

Method: In this study, 147 patients (mean age: 48.8 years; SD: 11.0) with the diagnosis of a somatoform pain disorder were studied with regard to affective comorbidity, pain duration (months), maximum pain within the last month, minimum pain within the last month and medium pain within the last month, psychosocial disability within the last month and the presence of a sleep disorder.

Results: Eighty-four percent of the patients had a sleep disorder. The patients with a sleep disorder had significantly higher maximum and medium pain, a significantly higher level of psychosocial disability and a significantly lower overall subjective well-being. The medium pain and psychosocial disability in leisure and social activities are significant predictors for sleep disorder.

Conclusions: The presence of a sleep disorder may be a hint for higher pain intensity and a higher level of psychosocial disability. Sleep disorder may be a factor in the persistence and aggravation of pain as well as psychosocial disability. Therefore, sleep disorder should be integrated in the therapeutic targets. It is suggested that sleep disorder should be a diagnostic criterion in somatoform pain disorder.