Background: To elucidate the possibility of using the Minnesota Multifaceted Personality Inventory (MMPI) to predict the prognosis of somatoform disorders, which are often treatment-resistant, we investigated the prognosis of somatoform disorders predicted using the MMPI.
Methods: During the period from January 1, 2013, to December 31, 2017, 125 cases of somatoform disorder were diagnosed in the psychiatric department of Fukushima Medical University Hospital, among which, 67 were consultation-liaison psychiatry cases and 58 cases were only psychiatric cases. Clinical information, MMPI scores, and prognosis information were collected from medical records in each case, and then statistical analysis was performed.
Results: The results showed that the unchanged group had significantly higher scores than the improved group on only the Hy scale. Receiver operating characteristic analysis of the Hy scale scores of the improved and unchanged group was then conducted to calculated a cutoff value. The cutoff point was 73.5 with a sensitivity of 0.557 and a specificity of 0.717.
Conclusion: For patients diagnosed with somatoform disorder who had an MMPI Hy scale score higher than the cutoff value, improvement with conventional supportive psychotherapy or drug therapy was predicted to be difficult. Therefore, the cutoff point identified in this study appears to be an important index for selecting treatment for somatoform disorders.