A conceptual model of quality of life in schizophrenia: description and preliminary clinical validation

The utility of quality of life (QOL) as an evaluative tool in clinical psychiatric research and drug trials could be enhanced by developing appropriate conceptual models of QOL, specific for psychiatric disorders. In our proposed model, QOL of individuals maintained on antipsychotic drug therapy for schizophrenia, is viewed as the subject's perception of the outcome of an interaction between severity of psychotic symptoms, side-effects including subjective responses to antipsychotic drugs, and the level of psychosocial performance. In order to test the validity of the model in clinical setting, we selected a sample of 62 schizophrenic patients clinically stabilized on antipsychotic drug therapy, and measured their subjective QOL and other potentially relevant clinical and psychosocial factors. Standardized scales including the positive and negative syndromes scale (PANSS), abnormal involuntary movements scale (AIMS), Hillside Akathisia scale (HAI), and the social performance schedule (SPS) were used for this purpose. Results of a multiple regression analysis using subjective quality of life as the outcome variable, indicated that severity of schizophrenic symptoms (partial R2 = 0.32, p < 0.0001) and subjective distress caused by akathisia (partial R2 = 0.11, p < 0.01) and neuroleptic dysphoria (partial R2 = 0.06, p < 0.05), accounted for nearly half of the variance, while the contribution from the psychosocial indicators was negligible. These results broadly endorse key aspects of the proposed model, and suggest further studies in this direction. These results experiences during antipsychotic therapy can enhance patients' QOL. This conceptual model has been developed with particular focus on the impact of antipsychotic medications on the QOL of persons with schizophrenia. As such, it is more applicable to clinical trials of new antipsychotic medications but may not be broad enough to be applicable for other social or vocational interventions.