A SELECTIVE REVIEW OF POSSIBLE NEUROLOGICAL ETIOLOGIES OF SCHIZOPHRENIA

Attempts to research the biological correlates and etiology of schizophrenia have suffered from a lack of clear diagnostic differentiation. Proposed classifications of acute/chronic, paranoid/nonparanoid, and negative symptom/positive symptom lack sufficient discrimination between subgroups. Recent research on biochemical neurotransmission, particularly in the activity of dopamine and neuropeptides, in conjunction with neuropathological research into structural abnormalities, has led to a 2-syndrome hypothesis. The viral theory has recently been rejuvenated in light of the discovery of genetically transmitted retroviruses and confirmation of the season of birth effect in the Northern Hemisphere. Unfortunately, problems of neuroleptic drugs effects, the role of secondary symptoms, significant overlap between groups, and inconsistent results continue to confound comprehensive interpretation. © 1991.