L-DOPA HELPS POSITIVE BUT NOT NEGATIVE FEATURES OF NEUROLEPTIC-INSENSITIVE CHRONIC-SCHIZOPHRENIA

L-dopa (Sinemet-110 in a final dose equivalent to similar to 4 g per d ay) added to maintenance chlorpromazine, produced a small antipsychoti c effect in a group of eight severely impaired male chronic schizophre nic in-patients. Negative symptoms were unaffected by L-dopa, although the improvement in psychotic behaviour and positive symptoms was rest ricted to the four patients with the most severe negative symptoms mea sured during the control treatment period. These L-dopa responders als o tended to improve slightly when the dose of chlorpromazine was halve d, an indication of their poor, or even counter-therapeutic response t o conventional neuroleptic medication given in relatively high dosage. Signs of increased dopaminergic activity (raised eye blink rate and r educed plasma prolactin) were not observed in subjects showing an anti psychotic response to L-dopa. This raises the possibility that L-dopa may exert an antipsychotic effect in neuroleptic-insensitive subjects by altering noradrenergic activity in the brain.