Suicidal ideation and suicidal behavior according to the C-SSRS in a European cohort of Huntington's disease gene expansion carriers

Background Huntington's disease (HD) gene expansion carriers are at an increased risk of suicide, but so far, no studies have investigated the full spectrum of suicidality, including suicidal ideation, suicidal behavior and self-injurious behavior. Methods We included 1451 HD gene expansion carriers (age 48.4 years (SD 14.0), 54.8% female) of the REGISTRY study of the European Huntington's Disease Network. Lifetime suicidal ideation and suicidal behavior were assessed with the Columbia-Suicidal Severity Rating Scale. Motor symptoms and disease stage were assessed using subscales of the Unified Huntington's Disease Rating Scale, and depressed mood and irritability were assessed by the Problem Behaviors Assessment. Results Lifetime passive suicidal ideation was reported by 21.2%. Participants in stage II showed the highest prevalence rate of suicidal ideation, while participants in stage IV/V showed the highest prevalence of suicidal behavior. A lifetime suicide attempt was reported by 6.5% of the HD gene expansion carriers. In multivariate regression analyses, both suicidal ideation and suicidal behavior were associated with a depressed mood, and to a lesser extend to irritability. Limitations Results may have been affected by denial or recall bias and no conclusions can be made about the temporal and causal relationships with depressed mood and irritability because of the cross-sectional analyses. Conclusions Given the high prevalence of suicidal ideation and suicidal behavior in all stages of HD, it is important to screen HD gene expansion carriers for suicidal ideation and suicidal behavior on a regular basis in clinical practice.