PREVIOUS reports from this laboratory1-3 have described in patients with severe depression an alteration in glucose metabolism which is characterized by resistance to both endogenous and exogenous insulin. This form of insulin resistance appears unlike that of any previously described medical illness and it disappears when the depression is successfully treated with amitriptyline (Elanil). In the course of these studies it was observed that after successful treatment of depression with amitriptyline, the manic-depressive patients demonstrated prolonged hypoglycemia in response to exogenous insulin. At the time of the test four of these six patients demonstrated manic symptoms. This suggested that, in contrast to the insulin resistance of severe depression, mania may be associated with an increased sensitivity to insulin.
To examine the possibility that increased insulin sensitivity and other alterations in glucose metabolism are associated with mania, we administered the standard intravenous glucose tolerance test (GTT) and insulin tolerance test
Heninger GR, Mueller PS. Carbohydrate Metabolism in ManiaBefore and After Lithium Carbonate Treatment. Arch Gen Psychiatry. 1970;23(4):310-319. doi:10.1001/archpsyc.1970.01750040022004