We report the case of a 55-year-old female with a history of type-1 DM since the age of 11, and severe ocular and renal vascular complications thereof. While on the waiting list for pancreatic islet cell transplantation, she developed a manic episode that proved recalcitrant to a treatment with gabapentin, lorazepam and quetiapine. Moreover, her mental state affected adversely her already compromised glycemic control, requiring her psychiatric hospitalization. Her psychotropic medication was almost discontinued and replaced by oxcarbazepine (OXC) up to 1800 mg/day for 10 days.