Author response: Risk factors for suicidality in Huntington disease: An analysis of the 2CARE clinical trial.

On behalf of all authors, I am appreciative of Drs. Rato and Ferreira for their observations on our article.1 We agree that the pragmatic step of excluding severe psychiatric disease in a long study introduces limitations for what conclusions can be drawn. Drs. Rato and Ferreira highlight the risk factors for suicidality at large that were also relevant in our study population, which we believe supports that surveillance for these things may be effective in lessening suicidality risk during Huntington disease (HD) clinical trials. It would perhaps be surprising or worrisome if the standard risks did not apply in the HD population here, so confirmation of this notion is valuable. The associations between chorea and the total functional capacity score of 0 in any domain have some association with risk (both p = 0.06), as well as predictive testing's association with risk for suicide attempt ( p = 0.05). These items, and perhaps others, may help make risk mitigation more sensitive if used in a composite model. This idea will require further study, development, and testing. We agree that how the structured environment of a clinical trial influences risk, including the possibility of placebo effects or unspecified participation effects, and deserves further study. Please see our discussion paragraph, “The effects of participation in HD clinical trials on suicidal risk is not clear…”1