Do people diagnosed with psychosis spectrum disorders share the same personality space as the general population? Big Five complemented by the proneness to psychotic-like experiences/behaviors

Disintegration is a recently proposed broad, trait-like reconceptualization of the proneness to psychotic-like experiences/behaviors. We tested the assumption that the 6-factor model (Five-Factor traits plus Disintegration) was the most adequate one and that it was invariant across clinical and non-clinical populations. The clinical sample (n = 161) consisted of patients who had at least one psychotic episode, duration of illness less than 10 years, currently in remission. The general population (n = 409) was matched with the patient sample by age, gender, and education. NEO PI-R and DELTA were used to measure personality dimensions in both samples. Invariance of one to six-factor solutions was tested by Exploratory Structural Equation Modeling. We found that: (a) several criteria for deciding on the number of factors to retain converged to the conclusion that the assumed 6-factor model was the most adequate one, (b) the assumed factorial structure appeared to satisfy the criteria for the scalar invariance across the two samples, (c) all nine Disintegration subdimensions separated from the Big Five, forming the Disintegration factor, and (d) Disintegration was unrelated to Openness. The Big Five personality structure-complemented with disintegration-was invariant across individuals from the general population and patients with psychosis.