The prevalence of tardive dyskinesia after a nine month naturalistic randomized trial comparing olanzapine with conventional treatment for schizophrenia and related disorders

Aims of the study To assess the impact of olanzapine versus conventional neuroleptic therapy among subjects with schizophrenia on ratings of tardive dyskinesia (TD). Method The naturalistic study was conducted in three psychiatric hospitals in Brazil. Patients had a diagnosis of schizophrenia and related disorders (DSMIV) and with a BPRS score > 24. Patients were evaluated by means of the PANSS scale for symptomatology (Kay et al. 1986), the Clinical Global Impression, The UKU side effect rating scale (Lingjaerde et al. 1987), and the Tardive Dyskinesia AIMS scale (Guy et al. 1976). Patients were seen by the treating physician routinely while hospitalized and then monthly on an out-patient basis. All scale assessments were repeated after 9 months of discharge. Result The sample was comprised of 190 patients (99 in the olanzapine and 91 in the standard treatment), with a completion rate of 88.2 % for olanzapine and 84.9 % for the conventional treatment (p = 0.385, n. s.). The mean change from baseline in the PANSS total score favored olanzapine regarding negative symptoms (2.3, 95% C.I. 0.6-4.1, p