Treatment resistant depression or dementia: a case report

Summary: The current case describes a 78-year-old female with two previous episodes of major depression who presented with both symptoms of depression (amotivation and flattened affect) and typical symptoms of dementia (impaired memory and executive functioning). Even after a detailed clinical exam and neuropsychiatric testing, it remained difficult to definitively classify the diagnosis as either treatment-resistant depression or old-age dementia. After 8 weeks of inpatient treatment, including changing her reserpine-based antihypertensive medication, adjusting her antidepressants, and providing psychotherapy, her depressive and anxiety symptoms improved, but most of her cognitive symptoms persisted. Her symptoms did not change over 7 months of post-hospitalization follow-up. She subsequently developed advanced breast cancer and started chemotherapy; at this point her depressive and cognitive symptoms became more pronounced. We conclude that it will take two-to-three years of follow-up to determine whether the cognitive symptoms are residual to her depression or a newly emerging dementia (or both). This case shows that for elderly patients who have symptoms of both depression and dementia, detailed clinical examination and neuropsychiatric testing may need to be combined with longitudinal assessment of their responsiveness to treatment before a definitive diagnosis can be assigned.