Somatoform disorders are classified as neurotic disorders according to the 10th revision of the International Classification of Diseases (ICD-10)1) and the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM-IV-TR)2,3). Chronic pain is classified into nociceptive, neuropathic, and psychogenic pain4). Among these types, psychogenic pain is classified as persistent somatoform pain disorder in the ICD-10 and chronic pain disorder in the DSM-IV-TR5). In addition to the distress of experiencing the symptoms themselves, chronic pain is likely to cause secondary psychiatric disorders and a decreased ability to carry out activities of daily living (ADLs). Therefore, this disorder cannot be overlooked, especially as it can become a burden for health systems and the population at large6).
Pharmacotherapy in the form of selective serotonin reuptake inhibitors, antipsychotic drugs, and benzodiazepine anxiolytics are useful to some extent for somatoform disorders7), however no effective treatment has been established. While research on the neural basis of these disorders is currently in progress, recovery from somatoform disorders is often difficult and largely dependent on psychosocial treatment8).
Since 1996, as part of consultation-liaison psychiatry services, conferences which consist of teams that include orthopedists, psychiatrists, nurses, physical therapists, psychologists, pharmacists, and social workers, have been conducted at Fukushima Medical University Hospital (FMUH). These conferences are held once a month and involve discussions on how to manage the psychosomatic problems of patients with somatoform disorders. Owing to these conferences, we have accumulated substantial Minnesota Multifaceted Personality Inventory (MMPI) data for these cases. Many patients with psychosocial personality problems or psychiatric disorders have a history of consultation with an orthopedist because of chronic pain and numbness or have not been satisfied with conventional orthopedic treatment5,9).
The multidisciplinary nature of these conferences is based on recognition of the role that “team medical care” has in promoting effective treatment and solving various problems. Specifically, a psychiatrist reviews patients who are identified at these meetings as having psychiatric problems, like a somatoform disorder. In addition, the orthopedist remains involved in treatment because even if the patient has psychiatric, psychological, or social problems, the chief complaint is a physical symptom5,9).
Numerous studies have reported personality tendencies in patients with somatoform disorders based on the MMPI10-18). However, to the best of our knowledge, no studies have assessed the utility of the MMPI in predicting the prognosis of somatoform disorders, and only a few studies have used it to predict outcomes of surgical treatment for chronic back pain19-22). We hypothesized that the accumulated MMPI data on the aforementioned cases could be used for the purpose of evaluating whether patients with chronic pain have latent paranoia, depression, or other psychiatric disorders, as well as whether their personalities affect their symptoms23,24).
Using MMPI for predicting the prognosis of somatoform disorders, treatment may be initiated earlier and rendered more smoothly and effectively, and patients may be able to recognize the therapeutic effects sooner. In addition, condensing the MMPI to identified key scales consisting of items predictive of negative outcomes may be more useful and help reduce the psychological burden on target patients.
The present study had two purposes: one was to clarify the psychological and biological factors associated with the clinical outcomes of somatoform disorders, and the other was to identify key scales of the MMPI that are predictive of negative outcomes. Towards these goals, we collected data from patients who had undergone assessment using the MMPI in the clinical setting, classified the patients into two groups (improved group vs. non-improved group based on the chart review, and examined these groups. In addition, we also identified the scales of the MMPI that were associated with outcomes and then determined the optimal cut-off values for predicting clinical outcomes by these scales.