An Exploratory Study of MMPI-2-RF Personality and Psychopathology Profiles of Adults with Autism Spectrum Disorder without Intellectual Disability.

Objective: More empirical research is needed to disentangle the phenotypes of autism spectrum disorder (ASD) and cluster C personality symptomatology (CCPD), as both show similarities in their clinical presentation. We explored personality and psychopathology dimensions as conceptualized in contemporary dimensional taxonomies (i.e., hierarchical taxonomy of psychopathology; HiTOP) in adults with ASD without intellectual disability operationalized by the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF).

Method: Applying secondary analytic processes using clinical data, we cross-examined the MMPI-2-RF profiles of adults with ASD ( n = 28) compared to adults with Cluster C personality disorders (CCPD; n = 28) and a control group ( n = 28) by conducting nonparametric tests and assessing effect sizes.

Results: The profiles of the ASD and CCPD groups evidenced to be similar, and both average clinical profiles diverged from the average control group profiles by elevated levels of demoralization, internalizing, and somatization symptomatology. There were small differences between the average profiles of adults with ASD and adults with CCPD. Additional research using dimensional measures of psychopathology could elucidate the dimensional phenotypes of ASD and CCPD.

Conclusions: Based on the results in this study, the MMPI-2-RF may not meaningfully discriminate between the two clinical presentations, with the exception of various externalizing scales.