These data support the idea that depression, anxiety, fatigue, and even psychosis are important symptoms of PHPT and may lead to an early diagnosis in patients otherwise asymptomatic, and further trials are necessary to pinpoint the prevalence and severity of the pathogenic connection with high PTH and/or calcium, in addition to finding more evidence for which sub-group of patients is at a higher risk for such ailments and if PHPT management should be adjusted under these circumstances. The gene discussed is PTH; the disease is major depressive disorder.