Efficacy of Treatment for Somatoform Disorders: A Review of Randomized Controlled Trials

To review the evidence from randomized clinical trials (RCTs) that have focused on the treatment of patients with Diagnostic and Statistical Manual of Mental Disorders, 4^th Edition (DSM-IV) somatoform disorders. Although somatoform disorders are among the most common mental disorders presenting in the general medical setting, the strength of evidence for specific treatments has not been well synthesized. Methods: MEDLINE search of articles published in English from 1966 to 2006, using the following search terms: randomized clinical trial, somatoform disorders, somatization disorder, undifferentiated somatoform disorder, hypochrondriasis, conversion disorder, pain disorder, and body dysmorphic disorder. Results: A total of 34 RCTs involving 3922 patients were included. Two thirds of the studies involved somatization disorder (n = 4 studies) and lower threshold variants, such as abridged somatization disorder (n = 9) and medically unexplained symptoms (n = 10). Cognitive behavioral therapy (CBT) was effective in most studies (11 of 13), as were antidepressants in a small number (4 of 5) of studies. RCTs examining a variety of other treatments showed benefit in half (8 of 16) of the studies, the most consistent evidence existing for a consultation letter to the primary care physician. Effective treatments have been established for all somatoform disorders except conversion disorder (1 of 3 studies showing benefit) and pain disorder (no studies reported). Conclusion: CBT is the best established treatment for a variety of somatoform disorders, with some benefit also demonstrated for a consultation letter to the primary care physician. Preliminary but not yet conclusive evidence exists for antidepressants.