Background The suicide risk in Huntington's disease (HD) is 4–8 times higher compared to the general population, and the prevalence of suicidality (suicidal thoughts and attempts) in HD is also increased. Several previous studies reported depressed mood as an important association of suicidality in HD.

Aims This study investigates clinical associations and predictors of suicidality in a large European cohort of HD mutation carriers.

Methods Presence of suicidality in the preceding month was assessed in 2106 mutation carriers from 15 European countries, all participating in the European Huntington Disease Network (EHDN) REGISTRY study. Mutation carriers were considered suicidal if the total score on the item “suicidal ideation” of the Unified Huntington's Disease Rating Scale (UHDRS) was >1point. Associations of suicidality were analysed using multivariate logistic regression analysis. Of the 1937 participants free of suicidality at baseline, 945 had one or more follow-up measurements. Cox regression analysis was used to determine predictors of suicidality.

Results At baseline, 169 (8%) mutation carriers were considered suicidal. Cross-sectionally, the presence of anxiety (OR=2.1), aggression (OR=2.4), a suicide attempt in the past (OR=4.0) and a depressed mood (OR=13.7) were independently associated to suicidality. During follow-up, 45 (5.5%) mutation carriers became suicidal. The presence of a depressed mood (OR=2.0; 95% CI 1.0 to 3.8) and use of benzodiazepines (OR=2.4; 95% CI 1.2 to 4.9) at baseline were independent predictors of suicidality at follow-up.

Conclusions Suicidality prevalence is increased in HD mutation carriers. Assessment of depressed mood, which is an important association and predictor of suicidality, can help to identify mutation carriers with an increased suicidality risk.