Incorporation of 14C-arachidonic acid into platelet phospholipids of untreated patients with schizophreniform or schizophrenic disorders.

The incorporation rate of 14C-labeled arachidonic acid (14C-AA) into membrane phospholipids was measured in a group of untreated (greater than 6 months) psychiatric patients (n = 33) and healthy controls (n = 31). Platelets from controls and from patients with schizophrenia (n = 10), schizophreniform disorder (n = 11), schizoaffective disorder (n = 6), major depression (n = 2), or an atypical psychosis (n = 4), diagnosed according to DSM-III, were incubated with 14C-AA. Platelets from patients with a schizophreniform and a schizoaffective disorder incorporated greater than 50% less 14C-AA than the platelets from controls. The incorporation rates of platelets from schizophrenic patients were slightly (18%), but not significantly, reduced compared to controls. Characterization of variables affecting arachidonic acid and phospholipid metabolism may be helpful in studies focused on the assessment of first-episode psychotic patients and in long-term outcome studies.