Weight gain as a prognostic indicator of therapeutic improvement during acute treatment of schizophrenia with placebo or active antipsychotic

Abstract

Treatment-emergent weight gain may be a general marker of therapeutic improvement, even when improvements occur in the absence of active antipsychotic treatment. To investigate the association between treatment-emergent weight gain and therapeutic improvement across placebo and active treatments, and to examine the association between reported treatment-emergent weight changes and the treatments’ reported efficacy. Data from a randomized, double-blind trial comparing treatment of schizophrenia with placebo and olanzapine were used to correlate weight change and change in psychopathology. Additionally, we correlated effect sizes of the efficacy of clozapine, olanzapine, risperidone, haloperidol and placebo (reported in meta-analytical reviews), with their reported weight changes. Weight gain significantly correlated with clinical improvements for placebo and olanzapine. The correlation between treatments’ efficacy and corresponding weight changes was high (r 0.88, p 0.05). Treatment-emergent weight gain appears to be an important marker of symptom reduction, and may not be exclusively attributable to pharmacological perturbations.