The Treatment of Psychotic Depression in a 64-Year-Old Patient With Carcinoid Syndrome

Serotonin-producing tumours are a subset of neuroendocrine tumours which, when active, can lead to carcinoid syndrome caused by the secretion of vasoactive substances such as serotonin, histamine, and bradykinins. In addition to the common symptoms of flushing, diarrhoea, abdominal pain, and carcinoid heart disease, carcinoid syndrome is also known to cause psychiatric symptoms of depression as well as anxiety and, very rarely, psychotic symptoms. The treatment of the neuropsychiatric manifestations of the disease is also complicated by the concurrent use of somatostatin analogues, which also affect total circulating serotonin levels, a neurotransmitter implicated in the aforementioned psychiatric disorders. In this case report, we will discuss the management of psychotic depression in a 64-year-old female patient with a metastatic carcinoid tumour and our rationale for the use of vortioxetine in her treatment.