Intravenous Glucose Tolerance Test in Depression

REPORTS on glucose utilization in depressive illness, as measured by the intravenous glucose tolerance test (GTT), are in conflict. In 1958 pryce^1,2 reported that depressed patients had lower glucose utilization rates (k) than normal subjects. This lowered k was not related to loss of body weight, and it did not change significantly following successful treatment with electroconvulsive therapy (ECT). Herzberg et al in 1968³ reported, however, no clear association between depression and lowered oral or intravenous GTT. These authors reported no significant change in glucose utilization rate following recovery whether ECT, tryptophan, or no somatic treatment was employed. They attributed previously reported positive findings of the GTT in depression to either malnutrition or inactivity. Pryce's data were more consistent with the report by Van Praag and Leijnse in 1965^{4 6} where decreased glucose utilization, as measured by forearm arteriovenous glucose difference, was associated with depressive illness.