Neuroleptic withdrawal in treatment-resistant patients with schizophrenia: tardive dyskinesia is not associated with supersensitive psychosis.

The objective of this retrospective study was to determine whether tardive dyskinesia (TD) represents a risk factor for supersensitive psychosis (SS) by assessing the effect of medication withdrawal on ratings of psychopathology for 30 days following discontinuation of antipsychotic medication in patients with and without TD. The subjects were 101 treatment-resistant patients with schizophrenia who had been admitted to the inpatient service of Neuroscience Research Hospital (NRH), National Institute of Mental Health, between 1982 and 1994 to undergo studies involving discontinuation of antipsychotic medication. Patients were rated independently on a daily basis on the 22-item Psychiatric Symptom Assessment Scale (PSAS), an extended version of the Brief Psychiatric Rating Scale (BPRS). The overall frequency of TD was 35.6%. Tardive dyskinesia patients were older (p < 0.0006) and had suffered from schizophrenia for a longer time (p < 0.003) than No-TD patients. Repeated measure ANOVA revealed a "time" effect for all subgroups studied. The interaction TD x time, however, was not statistically significant for any of the clusters. Within-group analysis revealed significant differences against baseline for measures of positive symptoms, negative symptoms and abnormal involuntary movements in the No-TD group 3 and 4 weeks after antipsychotic withdrawal. In the TD group, however, the changes were observed only at 4 weeks following antipsychotic discontinuation in just two of the positive symptoms cluster. Between-group analyses revealed that, at baseline, the Mannerisms cluster (abnormal involuntary movements) was significantly higher in the TD group (p < 0.05). No significant differences were observed between any of the remaining clusters at baseline or at different times following drug withdrawal. In conclusion, the relationship between SS and TD could not be confirmed in a cohort of patients with treatment-resistant schizophrenia. In the present study, patients with no TD seemed to deteriorate faster than patients with TD in terms of psychopathology and abnormal involuntary movements. It is possible that both group of patients may undergo supersensitive receptor changes, and that these changes may be more pronounced but potentially reversible in the group without TD.