MEMBRANE FATTY-ACIDS, NIACIN FLUSHING AND CLINICAL-PARAMETERS

Clinical definitions of schizophrenia are unreliable and difficult to use. The niacin flush test, which involves prostaglandin-induced vasod ilatation, offers a method of exploring essential fatty acid metabolis m in schizophrenic patients and may serve to define a subgroup of pati ents. In a multicentre study of schizophrenic patients with negative s ymptoms, we have examined the clinical accompaniments of the niacin re sponse. Patients failing to flush with niacin showed significantly red uced levels of arachidonic and docosahexaenoic acids. Conversion from non-flushing to flushing during the 6 month supplementation period was predicted by an increase in arachidonic acid levels in red blood cell membranes irrespective of nature of supplementation. In this study, p atients were selected for their negative symptoms and, therefore, it w as not surprising that further measures of negative or positive sympto ms did not predict flushing. However, an increased score for affective symptoms was significantly associated with a positive flush response. The stability of the niacin test needs to be examined in relation to the periodicity of symptoms in schizophrenia and manic depressive illn ess. New information on the anandamide system suggests that it may be associated with periodic phenomena and should be investigated in relat ion to the niacin test.