Time discrimination: a comparison between healthy controls, unmedicated schizophrenics, zotepine-treated schizophrenics and schizophrenics treated with conventional neuroleptics

In a cross-sectional study time discrimination performance was examined of healthy controls, unmedicated schizophrenics, zotepine-treated schizophrenics, and schizophrenics treated with conventional neuroleptics (haloperidol, fluphenacine). There were no significant differences among the groups in age and gender, the schizophrenic groups were not significantly different in BPRS-score and cumulative length of stay. The medication of the patients treated with neuroleptics was given in equipotent doses. Statistics was performed by ANOVA and subsequent Least Significant Difference (LSD) Test. In relation to the healthy controls a significant impairment of time perception of unmedicated schizophrenic patients as well as conventionelly treated schizophrenic patients could be demonstrated, but not of patients treated with zotepine. Further, unmedicated and conventionally treated patients showed a significant impairment in time estimation compared to patients treated with zotepine. The study shows an illness-related impairment among schizophrenics with a positive effect of zotepine on time discrimination performance. The receptor binding profiles of the various drugs as likely cause of these differences are discussed.