A Case of Cushing Syndrome Misdiagnosed as Treatment-Resistant Depression

Cushing’s syndrome is a systemic disease resulting from chronic exposure to cortisol excess, occurring at a rate of 0.7 to 2.4 per million per year.1,2 An abundance of glucocorticoid receptors found in the central nervous system makes the brain susceptible to states of glucocorticoid excess.1 Depression is the most common neuropsychiatric manifestation of Cushing’s syndrome, present in 50%-80% of patients with active disease, with suicidal ideation reported at a rate of 17%.1 Neuropsychiatric symptoms can precede the onset of Cushing’s syndrome,3 making diagnosis challenging.