A meta-analysis of the response to chronic L-dopa in patients with schizophrenia: therapeutic and heuristic implications.

Rationale: While it is generally believed that administration of the dopamine precursor levodopa ( L-dopa) exacerbates symptoms of schizophrenia, numerous reports suggest that adjunctive L-dopa may be beneficial. This body of literature has not been critically reviewed.

Objectives: On the basis of published studies, to determine whether L-dopa administered concomitantly with antipsychotic drugs provides a beneficial response in patients with schizophrenia.