Lithium prevents adaptation of brain dopamine systems to haloperidol in schizophrenic patients.

To evaluate the effect of lithium treatment on haloperidol-induced changes of brain dopamine systems, cerebrospinal fluid homovanillic acid (HVA) was assessed in nine patients during a sequential treatment protocol with placebo, lithium, lithium plus acute haloperidol, and lithium plus chronic haloperidol. None of the patients developed tolerance to the rise in HVA during treatment with haloperidol and lithium. Concurrent treatment with lithium appears to prevent the development of tolerance in dopamine metabolism during chronic haloperidol treatment. These data provide the first evidence in man that lithium may prevent neuroleptic-induced functional supersensitivity of brain dopamine systems.