ANTIPSYCHOTIC EFFECTIVENESS FOCUSING ON INSIGHT

Abstract Background Impaired insight is common among patients with schizophrenia, and a major obstacle for treatment adherence and improvement. Previous studies have investigated the effect of antipsychotics on insight, but findings are indecisive due to small or homogeneous samples, non-randomized design or short follow- up. The aim of this study was to investigate if there were differential effects on insight among different antipsychotic medications, and whether the effect was directly related to improvement in insight or indirectly through reduction of psychosis symptoms. Methods Data was derived from the Bergen-Stavanger-Innsbruck-Trondheim study (BestIntro). This is a randomized, rater-blinded, naturalistic study with a head- to head comparison of three antipsychotic medications: amisulpride, aripiprazole and olanzapine. Inclusion criteria were adults with a F20-F29 ICD-10 diagnosis being actively psychotic defined as a score of ≥4 on items P1, P3, P5, P6, or G9 on the Positive And Negative Syndrome Scale (PANSS). Insight was measured by PANSS item G12. We used a modified version of PANSS to assess psychosis symptoms (PANSS total score minus item G12, mPANSS). Level and change in insight and psychosis symptoms were estimated in latent growth curve models. The pattern of change indicated a piecewise model with the initial phase from baseline to week six and the long-term phase from week six to one year. The study drugs were used as predictors. Results A total of 144 participants were included, 35% female and 61% had previously used antipsychotic medication. Mean insight score at baseline was 3.36. Preliminary findings show differential effects on insight among the three medications, where aripiprazole was the least effective drug. The effect on insight was related to improvement in psychosis symptoms for all study drugs. In addition, we found a direct effect on insight in the long-term phase for amisulpride and olanzapine. In the same phase, the aripiprazole group showed a slight increase in impaired insight. Discussion This is the first randomized study with a heterogeneous sample to find an effect of antipsychotics on insight that exceeds the contribution of reduction of psychosis symptoms. Although we have not investigated the association between increased insight and medication adherence, our results imply that patients with impaired insight will benefit from antipsychotic treatment. More specifically, treatment with amisulpride or olanzapine may be more helpful in improving insight over time.