Suicidal behavior in prodromal Huntington disease

Abstract

Background: Several studies have suggested a greater risk of suicide in Huntington disease (HD); however, unique risk factors for suicide in HD are not established.

Objective: We sought to determine risk factors for suicidal behavior, defined as suicide or attempted suicide, in prodromal HD.

Methods: From the prospective PREDICT-HD cohort, we identified 735 cases with HD gene expansion but no manifest symptoms of HD and 194 non-gene-expanded controls. In survival analysis, a number of potential risk factors for suicidal behavior were assessed, including symptoms of depression, hopelessness, substance abuse, marital status, gender, and psychiatric history.

Results: During a mean of 3.7 years of prospective follow-up, 12 cases (1.6%) attempted suicide and 1 completed suicide (0.1%). No suicides were observed among controls. In univariate Cox proportional hazards regression models, a history of suicide attempts (HR 8.5, 95% CI 2.8-26.1, p < 0.0002) and a Beck Depression Inventory II score >13 (HR 7.2, 95% CI 2.3-22.0, p < 0.0006) were associated with suicidal behavior. These risk factors had independent effects in multivariate models. A history of incarceration in the past 2 years was also associated (HR 12.5, 95% CI 2.7-56.6, p < 0.002), though uncommon. No further risk factors were identified.

Conclusion: A history of suicide attempts and the presence of depression are strongly predictive of suicidal behavior in prodromal HD. As these risk factors are among the most robust risk factors for suicide, established suicide risk factors appear applicable to those with prodromal HD.