Psychopathology and the Validity of Gastrointestinal Symptom Reporting as Revealed Through Cluster Analyses of MMPI-2-RF Results

Psychological state, self-reported gut symptoms, and somatic complaints are recognized relationships that can impact health assessment and subsequent treatment.

To investigate the impact of psychological state and personality on symptom self-reporting and somatization.

Sixty-two (62) participants from the Hunter region of NSW (Australia) undertook a survey of health and lifestyle along with an MMPI-2-RF assessment of personality, psychopathology, and test-taking attitude. Participants also completed the Rome Criteria to assess functional gastrointestinal disorders (FGIDs). To assist the interpretation of MMPI-2-RF results, clustering was applied to identify similar responses and sub-cohort profiles of reporting.

Cluster analysis revealed four sub-cohorts, stratified by psychopathology, gut-related symptoms, and the validity of self-reported somatic complaints. Sample clustering identified one sub-cohort defined by high rates of negative affectivity and suicidal ideation. Apart from these differences, clusters were uniform for age, sex, smoking, mental health diagnoses, as well as for gut-related conditions.

Results provide further evidence of the interaction of the gut–brain axis and its relationship to serious mental health conditions. It also points to the need to assess the veracity of self-reported symptomatology that may be both pathognomonic for psychopathology but might also be a consequence of gut dysbiosis. Clustering assisted these investigations by defining distinct sub-cohorts based on participant MMPI-2-RF responses.