Carbamazepine as an adjunct of antipsychotic therapy.

The effect of low-dose haloperidol combined with the anticonvulsant carbamazepine was investigated in a 5-week placebo-controlled, double-blind study in acute schizophrenic patients. Weekly ratings showed a clinically pronounced and statistically significant improvement in both the carbamazepine and placebo groups. However, the patients on carbamazepine needed less neuroleptic and anticholinergic medication and experienced fewer side effects compared to the patients on placebo. Moreover, patients in the carbamazepine group showed a clear deterioration after discontinuation of carbamazepine (but maintenance of neuroleptic medication), while the placebo group did not change after discontinuation of placebo. Concomitant treatment with carbamazepine in psychotic patients may help to reduce neuroleptic dosages and unwanted side effects.