Abstract The incidence of mental health disorders is significantly higher in individuals with a rare disease, compared to the general population. This letter considers the possible reasons for this in terms of the many ways in which a rare disease impacts on an individual’s life, and how these impacts can be strongly related to factors which predispose to mental health difficulties. Furthermore, issues surrounding mental health can also play a significant role in the process of diagnosing a rare disease. The unusual nature of such diseases intrinsically predisposes an individual to obtain an inaccurate diagnosis of a psychosomatic disorder, a diagnosis which can often be further complicated by the presence of genuine psychiatric symptoms. This letter argues that these common experiences of rare disease patients have impacts upon the way in which their psychiatric care should be offered and managed, and that sensitivity and understanding surrounding these issues should be considered a necessary part of effective care for rare disease patients.