THE ROLE OF SEROTONIN IN SCHIZOPHRENIA

The hypothesis that the LSD psychosis and by inference schizophrenic p sychoses are related to dysfunctions in central serotonergic systems, formulated by Woolley and Shaw in the early 1950s was the first testab le theory of modern biological psychiatry. Initially, it did not get t he scientific attention it deserved. First, because LSD fell into disr epute and was to all intents and purposes banned from human experiment ation. Secondly, the antipsychotics were discovered in the same period , and it became clear that these compounds block dopaminergic transmis sion and hence for many years thereafter the dopaminergic system occup ied center stage in biological schizophrenia research. Presently, inte rest in the relation between serotonin and schizophrenia has been revi ved, due to the development of serotonin-blocking agents that appear t o exert therapeutic effects in schizophrenia. In this paper the eviden ce for and against a link between serotonergic defects and schizophren ia psychopathology is critically discussed. The conclusion to be reach ed is threefold. (1) Interruption of certain serotonergic circuits rep resents an antipsychotic principle. (2) Tentative evidence suggests th e involvement of serotonergic dysfunctions in the pathogenesis of schi zophrenic psychoses. (3) It is not yet known whether serotonergic lesi ons contribute directly to the occurrence of schizophrenic psychopatho logy or via alterations in the dopaminergic system.