Behavioural and biochemical effects of l-dopa in psychiatric patients

Abstract

Publisher Summary This chapter elaborates the behavioral and biochemical effects of l -dopa in psychiatric patients. Administration of the dopamine precursor, l -dopa to Parkinsonian patients has frequently precipitated psychotic reactions of various types. Patients who consented to participate were maintained on matched placebo for 5–10 days before l -dopa was administered. The first patient showed hypersexuality and compulsive masturbation without other signs suggestive of hypomania such as euphoria or hyperactivity. The second showed no objective behavioral effects and tolerated dosages of 10 g l -dopa day. Two other patients showed a combination of nausea, diaphoresis, a sense of dysphoric stimulation and anxiety. One of these developed ideas of reference. The remaining patient, who had no history of psychosis or psychiatric signs suggestive of schizophrenia, developed a paranoid schizophreniform psychosis. The precipitation of a schizophreniform psychosis by administration of l -dopa in a patient documented to be non-schizophrenic prior to receiving the drug also supports the hypothesized relationship between psychosis and central dopaminergic activity.