Longitudinal comparative study of risperidone and conventional neuroleptics for treating patients with schizophrenia

This study compared the long-term (12 months) effectiveness of risperidone (RP) with that of conventional neuroleptics (CNs) in a population with chro nic schizophrenia who had shown suboptimal response to CNs. A randomized, o pen, parallel, multicenter design was used. One hundred eighty-four subject s meeting DSM-IV criteria for schizophrenia were randomly assigned to recei ve either RP or a CN, and 165 of them completed the follow-up. Outcome meas ures were taken at 3, 6, and 12 months and included the Positive and Negati ve Syndrome Scale (PANSS) and the Extrapyramidal Symptom Rating Scale. With in this 12-month follow-up, RP was found to be superior to CNs in terms of both. the average change in score from baseline on the PANSS (p = 0.006) an d the proportion of good responders (as defined by a 20% decrease in total PANSS scores; p = 0.03). For positive symptoms, the effectiveness of the RP treatment tended to increase over time. At 12 months, the percentage of go od responders in the RP group was twice as large as that in the CN group (3 0% vs. 15%;p = 0.03). The superiority of RP over CNs was constant over the three dose categories. In both the RP and the CN groups, the maximum decrea se in psychopathology was achieved with the lowest dose range. A worsening of akathisia was less frequent in subjects receiving RP than in those recei ving CNs (p = 0.02). In conclusion, this study showed that, compared with C Ns, RP is beneficial in the treatment of patients with chronic schizophreni a and that some of these benefits may appear only after longer-term treatme nt.