Correlation Between Violence and Antipsychotic Dosage in Schizophrenia: A Secondary Analysis of The Clinical Antipsychotic Trials for Intervention Effectiveness (CATIE) Dataset

Abstract

Introduction Violent behavior is more common in individuals with schizophrenia, compared to the general population. Studies suggest higher psychotic symptoms are predictive of greater violent behavior. On the other hand, violent behaviors are reduced with antipsychotic treatment. However, the relationship between antipsychotic dosage and violence has not been studied to date. Thus, we aimed to determine if there exists an association between antipsychotic dosage and violence scores and whether the maximum violence would be predictive of the final antipsychotic dosage. We hypothesized that the violence scores at the final assessment in the Clinical Antipsychotic Trials for Intervention Effectiveness (CATIE) would be correlated with the corresponding drug dosage and the maximum violence severity score would be predictive of the final dosage.

Methods Antipsychotic dosage at the end of the trial was converted into defined daily dosage and chlorpromazine equivalents (CPZe). Final and maximum violence sum scores were analyzed from the final violence assessment interviews. Spearman’s rank-order correlation and linear regression analyses were used to analyze the relationship between the violence scores and standardized antipsychotic dosages.

Results The analysis was on 952 individuals with schizophrenia. There was a significant association between maximum violence severity score and the final CPZe dosage (p=0.049). Exploratory analysis of age and ethnicity revealed younger non-white individuals to be at a higher risk of engaging in violent activities.

Discussion Violence in schizophrenia is associated with poor illness course. Further studies focusing on violence in younger non-white individuals are warranted.

Key words

violence - schizophrenia - antipsychotics - dosage - CATIE

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