A biochemical basis for psychotic symptoms in patients with brain dysfunction.

Thirteen brain dysfunctional patients with psychosis were compared to 11 brain dysfunctional patients without psychosis by EEG, CT scan and neuropsychological test abnormalities, and abnormalities in serine metabolism. None of the tests of conventional measures of brain pathology and pathophysiology significantly differentiated between the psychotic and nonpsychotic patients; only the last measure which has previously been shown to be a biochemical vulnerability factor for psychosis, was significantly different in the two groups. This study suggests that the brain pathology and pathophysiology per se are not significant factors that make such patients psychotic, but these patients are vulnerable to psychosis because of a biochemical abnormality.