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

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

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

Methods: 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.

Results: 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.

Conclusion: 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.