LAUSR

I appreciate Dr. Aziz's thoughtful comment and agree that confounding by indication is an important issue to consider in this analysis.1 Weighting cases based on this method would be more useful if the frequency and severity of depression and suicidal ideation were known when tetrabenazine (TBZ) was prescribed. However, in this cross-sectional analysis, TBZ users were on therapy for 2.58 years at the baseline visit, making it difficult to determine if depression or suicidality factored into the decision to initiate therapy.2 Nevertheless, we performed the same analyses described in the article after applying inverse probability of treatment weighting, using propensity scores that were calculated based on whether a participant had a personal history of depression.1 TBZ use was associated with a decreased risk of depression (odds ratio [OR] 0.81, p = 0.001) and suicidality (OR 0.70, p = 0.002) among all participants, as well as those with only a personal history of depression (OR 0.75, p < 0.0001, and OR 0.64, p < 0.0001, respectively). There were no significant differences among participants without a personal history of depression. These findings only support the conclusion that TBZ may be safely used to suppress chorea in patients with Huntington disease who have a history of depression or suicidality, but should not be interpreted as being beneficial for depressive symptoms.