Background: Insight in psychosis and schizophrenia is considered a complex biopsychosocial phenomenon. Premorbid personality is regarded by some authors as part of the substrate to many psychiatric phenomena, but it is not clear if this applies to insight.
Aim: To examine longitudinal relationships between personality traits and insight dimensions in first-episode psychosis.
Methods: One hundred consecutive antipsychotic-naïve first-episode nonaffective psychotic patients admitted to hospital were included in the study. Eighty-one patients completed at 1 month a premorbid personality evaluation, plus baseline, and 6-month insight assessments. We used the Assessment and Documentation of Psychopathology inventory for assessing insight dimensions (not feeling ill, lack of insight, and refusal of treatment) and the Personality Assessment Schedule for ascertaining 5 dimensions of premorbid personality (schizoid, passive-dependent, anancastic, sociopathic, and schizotypy).
Results: At baseline, personality dimensions did not show any association with insight dimensions, with the exception of schizotypy traits. At 6 months, schizoid and sociopathic personality showed a significant association with not feeling ill (r = .30, P ≤ .007; r = .27, P = .01) and lack of insight (r = .36, P = .001; r = .41, P < .001), respectively. When we calculated insight change, schizoid and sociopathic personality had moderate correlation with the lack of insight dimension (r = -.34, P = .002; r = .38, P < .001, respectively). After applying partial correlations for potential confounders and Bonferroni correction, the associations remained significant. Moreover, using a regression model, sociopathic and schizoid personality significantly predicted lack of insight at 6 months and change from baseline to the 6 months assessment.
Conclusions: Sociopathic and schizoid personality dimensions were not only significantly associated with lack of insight at 6 months but also predicted change on lack of insight over 6 months. Therefore, exploring premorbid personality traits at the beginning of a psychotic episode may be helpful in identifying patients at high risk for lack of insight during the initial course of the illness.