Risk factors of suicidal ideation in Huntington's disease: literature review and data from Enroll-HD.

Suicide is a leading cause of death in Huntington's disease (HD), following pneumonia. Up to one-fifth of individuals with HD report suicidal ideation. Identifying the risk factors of suicidal ideation in this clinical population is thus pivotal. Here, we review the literature on prevalence rates and risk factors of suicidal ideation in premanifest and manifest patients and re-evaluate them using the largest currently existing clinical dataset from the ongoing observational study "Enroll-HD" (N = 5709). Large scale studies yielded important insights regarding suicidal ideation in HD. However, estimated prevalence rates vary among studies and risk factors are still poorly understood. According to the Enroll-HD data, pre- and manifest disease stages are associated with current (5.8-10%) and a history of suicidal ideation (18.6-30.9%). Throughout the course of HD, a history of suicidal ideation and the presence of depressive symptoms were strongly associated with current suicidal ideation. However, while for premanifest individuals, socio-demographics and activities of daily living appear to be important, in manifest patients, suicidal ideation is more closely linked to anxiety, irritability, psychosis, and apathy. These results highlight the importance of treating depressive symptoms in patients with HD and addressing potential suicidal ideation during clinical monitoring. The relevance of risk factors may differ among premanifest and manifest patients.