Recent studies have successfully investigated the validity of the DSM-5 Alternative Model for Personality Disorders. In a final sample of 174 psychiatric patients, the present study examined the relationship between the Personality Inventory for the DSM-5 (PID-5) and syndromal psychosis. Results showed that patients diagnosed with versus without a psychotic disorder significantly differed on all PID-5 domains except Antagonism. Discriminant function analysis indicated that lower Detachment, lower Negative Affect, lower Disinhibition, and higher Psychoticism best discriminated patients with a psychotic disorder from patients with other psychiatric conditions. Subsequent stepwise discriminant analysis on all facet scales of the contributing PID-5 domains revealed that higher Unusual Beliefs, lower Depressivity, and lower Distractibility contributed the most to this differentiation. PID-5 Psychoticism scores showed moderate correlations with current psychotic symptoms and were not influenced by dose of antipsychotic medication. Our results support the ability of the PID-5 to discriminate between patients with and without psychotic disorder.
Keywords: PID-5; antipsychotic medication; discriminant function analysis; psychosis; psychotic symptoms; psychoticism.