Premorbid functioning and treatment response in recent-onset schizophrenia: prospective study with risperidone long-acting injectable

Abstract

Premorbid functioning may be associated with treatment response, but this is confounded by a lack of prospective longitudinal data and controls for medication compliance. This study tested the hypothesis that good premorbid functioning will be associated with better antipsychotic treatment response after controlling for drug adherence by using a long-acting injectable antipsychotic. This was a 6-month, open label, multicenter, phase IV trial in recent-onset schizophrenia treated with flexible doses of risperidone long-acting injectable (25-50 mg every 14 days). Premorbid functioning was assessed with the Premorbid Adjustment Scale (PAS)-Structured Interview; efficacy was evaluated with clinician-rated Positive and Negative Syndrome Scale, Clinical Global Impression scale of Severity of Illness, Clinical Global Impression scale of Change, Global Assessment of Functioning Scale, and trial participant completed SF-36. Analyses controlled for baseline scores and demographics. With the use of a priori PAS scoring criteria, the participants' premorbid functioning was categorized as stable-good (n = 142), stable-poor (n = 116), and deteriorating (n = 36). At baseline, the stable-good group had the best functioning on most efficacy measures. All groups showed significant improvement on efficacy measures with treatment. Improvement was significantly higher for the stable-good group. The PAS global assessment of highest level of functioning scale (excellent, n = 75; good, n = 117; fair, n = 78; and poor, n = 31) showed a strong association with baseline functioning and improvement and had a significant linear association with meeting Remission in Schizophrenia Working Group symptom criteria at baseline (P = 0.003) and attained and sustained remission for 3 months during study (47.7%, 49.3%, 29.6%, and 22.2%; P = 0.006). Good premorbid functioning corresponds with better treatment response in recent-onset psychosis as captured on both clinician and patient-reported measures.