Intentional Insulin Overdose and Depression in Subjects with and Without Diabetes Mellitus: A Commentary

Insulin is an essential medication for people with type 1 diabetes mellitus and for some people with type 2 diabetes. Interestingly, insulin abuse has been reported as a mode of suicide, not only among people with diabetes, but also among their relatives, and among medical and paramedical personnel who have access to insulin. The aim of the present commentary was to raise awareness of potential depression-related intentional insulin overdose and its complications, as well as of the diagnosis and treatment of this entity. Insulin overdose may lead to severe and prolonged hypoglycemia, hypoglycemic coma, and death. Moreover, hypokalemia, hypomagnesemia, hypophosphatemia, and elevated liver enzymes are common. Insulin overdose should be suspected among people with diabetes in case of unexplained prolonged hypoglycemia and among people without diabetes who exhibit hypoglycemia and may have access to diabetic medications. The ratio of insulin to C-peptide helps distinguish exogenous insulin administration from endogenous secretion. The cornerstone of therapy is prompt administration of concentrated glucose infusions for days with simultaneous oral intake, when possible, and intense glucose monitoring to prevent hypoglycemia. Moreover, monitoring of serum electrolyte levels is recommended. Finally, psychiatric evaluation aiming at early identification of depression and suicidality is of paramount importance.