Effect of risperidone versus haloperidol on emotional responding in schizophrenic patients

Studies on emotional processing report that schizophrenic patients present a specific pattern of emotional responding that usually includes deficits in emotional expressiveness, increased feelings of unpleasant emotion but decreased feelings of pleasant emotion, and increased physiological reactivity. However, studies have rarely controlled the nature of antipsychotic medication. Yet, the influence of these drugs on emotional response is uncertain and could vary depending on their pharmacological profile.

This prospective and randomized study aimed to compare the effects of an atypical antipsychotic, risperidone, to a typical one, haloperidol, on patients' emotional responding during an emotional induction task.

Twenty-five schizophrenic patients underwent two emotional and clinical evaluations: one before treatment initiation and a second 4 weeks after. Emotional states of fear, sadness, anger, joy, and disgust were induced, as well as a neutral baseline state. Video recordings of patients during the induction task allowed for assessment of emotional expressiveness. Self-reports and measures of skin conductance and heart rate were performed to determine both subjective and physiological reactions to emotional experience.

Compared to haloperidol, risperidone did not reduce patients' facial expressiveness, decreased physiological reactivity, and decreased experience of unpleasant emotion but maintained experience of pleasant emotion. Emotional expressiveness was negatively correlated to parkisonism.

Our preliminary results suggest that atypical antipsychotics allow for better-adapted patterns of emotional responding than typical ones do. We suggest that this effect is due to reduced striatal D2 blockade, therefore, attenuating akinesia, coupled with increased 5HT and DA levels in prefrontal cortex, which improves emotional regulation.