A meta-analysis of studies with the Minnesota Multiphasic Personality Inventory in fibromyalgia patients

The Minnesota Multiphasic Personality Inventory (MMPI) has been widely used to assess personality and psychopathology in patients diagnosed with fibromyalgia, and the results have been contradictory. This work aims primarily at analysing whether the available empirical results with this instrument allow for a conclusion about personality traits and psychopathology of patients with fibromyalgia. Complementary, we evaluated whether the MMPI was able to discriminate these patients from healthy control groups. We carried a search on Medline, PsycINFO and Cochrane Database of Systematic Reviews, about studies evaluating personality and psychopathology of fibromyalgia patients with the MMPI, and the reference lists of retrieved studies were scanned for additional articles. A total of 11 studies fulfilled the inclusion criteria and were included. The hypochondriasis, depression, hysteria and schizophrenia scales were the more frequently elevated clinical scales across the included studies. A statistically significant heterogeneity was observed in all clinical scales. This meta-analysis confirmed the existence of a significant elevation in the neurotic triad. The considerable heterogeneity suggests that the fibromyalgia population is a heterogeneous group regarding personality and psychopathology profiles. The MMPI showed to be able to discriminate female patients with fibromyalgia from healthy volunteers.