Effectiveness of long-acting injectable risperidone versus oral antipsychotics in the treatment of recent-onset schizophrenia

Abstract

Long-acting injectable antipsychotics may offer a relevant improvement in treatment adherence in recent-onset psychosis, leading to a decreased rate of hospital readmission, a better rate of clinical remission and improved psychosocial adjustment. The aim of the study was to compare the clinical remission rates, number of hospital readmissions and personal and social functioning after 2 years between patients with recent-onset schizophrenia (<2 years) in treatment with risperidone long-acting injectable (RLAI) and patients with recent-onset schizophrenia receiving oral antipsychotics. This is a case-control study comparing patients with recent-onset schizophrenia who initiated RLAI treatment between 2004 and 2008 (n=26) with a control group matched for age and sex, diagnosed with recent-onset schizophrenia and treated with oral antipsychotics (n=26). Study assessments included sociodemographic variables, the Positive and Negative Syndrome Scale, the Personal and Social Functioning Scale, the number of hospital readmissions and the Andreasen remission criteria. To assess the effect of treatment on each dependent variable, separate generalized estimating equations models were constructed. After 2 years of treatment, and adjusting for educational level, the RLAI group showed a greater reduction in the Positive and Negative Syndrome Scale total scale [mean (SD)=47.7 (12.0) vs. 66.2 (18.5); mean difference =-17.56; 95% confidence interval (CI)=-27.11 to -8.00; P<0.001], as well as in the negative [mean (SD) 14.3 (6.1) vs. 19.4 (6.4); mean difference=-5.02; 95% CI=-8.28 to -1.77; P=0.002] and general psychopathology [mean (SD)=23.4 (6.3) vs. 32.7 (8.1); mean difference=-9.16; 95% CI=-13.3 to -5.03; P<0.001] subscales compared with the oral antipsychotic group. Personal and Social Functioning Scale scores were also higher in the RLAI group [mean (SD)=72.4 (14.8) vs. 59.7 (13.5); mean difference=13.41; 95% CI=5.65-21.18; P<0.001]. Although not statistically significant, there were fewer readmissions (adjusted odds ratio 0.28; 95% CI=0.06-1.35; P=0.114) and more illness remissions (adjusted odds ratio 3.24; 95% CI=0.20-11.93; P=0.077) in the RLAI group. Treatment with RLAI instead of oral antipsychotics in recent-onset schizophrenia might improve clinical symptoms and social functioning. The efficacy of RLAI treatment on remission and readmission rates should be researched further.