The effectiveness and predictors of response to antipsychotic agents to treat impaired quality of life in schizophrenia: A 12-month naturalistic follow-up study with implications for confounding factors, antidepressants, anxiolytics, and mood stabilizers

Abstract

Objective This study examined specific predictors of the efficacy of risperidone (RP), olanzapine (OL) and first-generation antipsychotic agents (FGAs), the role of confounding factors, and concomitant agents such as antidepressants, anxiolytics, and mood stabilizers in the treatment of health related quality of life (HRQL) impairment of schizophrenia patients. Method This was a community-based, open label, parallel group naturalistic study of 124 schizophrenia outpatients who received either RP, OL, FGA, or combined agents (CA). Evaluations were performed at baseline and 12 months later. They included the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q), the Positive and Negative Syndrome Scale (PANSS), the Distress Scale for Adverse Symptoms, and inventories for the assessment of distress severity, subjective tolerability, and self-efficacy. Results OL was found to be superior to RP, FGAs and CA in terms of quality of life. FGAs revealed greater therapeutic benefit than RP, which was more beneficial than combined therapy. Improvement in Q-LES-Q was revealed in patients who received antidepressants and anxiolytics, but not mood stabilizers, or anti-Parkinson drugs. This effect was independent of treatment groups and gender. Regression models revealed that changes in emotional distress and side effects were common predictors for HRQL changes across treatment groups. Specific predictors of HRQL efficacy included self-efficacy for OL, negative and positive symptoms for RP, dysphoric mood and positive symptoms, daily doses and self-efficacy for FGA treated patients. Conclusion These findings suggest that OL is beneficial in the treatment of HRQL impairment in schizophrenia compared with RP, FGAs and CA. Special attention should be paid to specific predictors of HRQL efficacy for each antipsychotic agent, and to concomitant treatment with antidepressants and anxiolytics.