Glucose-induced increase in memory performance in patients with schizophrenia

Previous investigations have found that increasing circulating glucose avai lability can increase memory performance in rodents, healthy humans, and in dividuals with dementia of the Alzheimer's type. In this study, patients wi th schizophrenia, healthy control subjects, and controls with bipolar affec tive disorder were tested using double-blind treatment with either 50 g anh ydrous dextrose plus 4 mg sodium saccharin (for "taste") or 23.7 mg sacchar in alone, followed by cognitive testing on a complex battery, At this gluco se dose, verbal memory performance on a paragraph recall task was increased during the glucose condition relative to the saccharin condition in the pa tients with schizophrenia; this effect was not detected in either the psych iatric or normal controls. The results provide preliminary support for the hypothesis that memory performance can be improved in patients with schizop hrenia by increasing circulating glucose availability and suggest the impor tance of further evaluation of therapeutic manipulations of glucose availab ility.