We report a case of an episode of major depressive disorder in a patient with a history of major depressive disorder who was stable and was recently started on exenatide for treatment of diabetes mellitus. The case raises the possibility of a link between exenatide and depressive symptoms. The case also highlights the need to be aware of the possibility of inducing depression with this drug and using caution when prescribing this drug to a geriatric patient.
This 70 year-old woman with a 35 year history of major depressive disorder had been stable on her regimen of fluoxetine 20 mg per day for over 10 years. She presented for admission to a psychiatric inpatient unit for worsening depressive symptoms including insomnia, anhedonia, apathy and passive suicidal ideation. Her current episode of depression began one year earlier, when she was started on exenatide 5 mg twice daily subcutaneously for treatment of her diabetes mellitus by her endocrinologist. One month after starting the exenatide, she began to feel more depressed. She was seen by her psychiatrist who switched her from fluoxetine to venlafaxine XR up to dose of 150 mg per day with no effect. After 3 months on the exenatide, she was taken off the medication. At that point, her depression gradually lifted and she felt back to her baseline within two weeks of being off the exenatide. She was maintained on the venlafaxine 150 mg per day with no depressive symptoms for 6 months. However, 1 month prior to her admission to the hospital, she was restarted on exenatide by her medical doctor. Within a week of restarting the medication, she started feeling depressed again with the symptoms mentioned above. She was admitted to the hospital and the exenatide was discontinued in consultation with her medical doctor. There were no other changes in her medication regimen and all blood work was normal. Within 1 week of stopping the