day; once every two days; once every three days; once every week and completely drug free) and each step lasted for six months. Serum prolactin levels in each patient were monitored in each step. Survival analyses for each treatment group were performed on the number of symptom-free days from the beginning of the trial until relapse symptoms appeared.
There was no signiยฎcant dierence in survival curves between the Trial group and the Continuous group analyzed over time with the generalized Wilcoxon test (Z 1X167Y p b 0X05). However a signiยฎcant dierence was obtained with the KaplanยฑMeier test over 750 days ( p 0X05). At this time point, the relapse rate was 60.0% in the Continuous group and 89.2% in the Trial group. The Trial group exhibited signiยฎcantly greater prophylaxis than the Placebo group analyzed over time with the generalized Wilcoxon test (Z 13X473Y p 0X01). Moreover, a signiยฎcant dierence was obtained with the Kaplanยฑ Meier test over 12 days ( p 0X05), and over 24 days ( p 0X01). Consequently, the intermittent withdrawal program with sulpiride was superior to an abrupt withdrawal of neuroleptics. Gradual intermittent treatment with sulpiride is a useful strategy for discontinuation of neuroleptics in remitted schizophrenic outpatients and intermittent treatment once every 3 days maintained dopaminergic inhibition of prolactin levels.