Effects of anxiety on suicidal ideation: exploratory analysis of a paroxetine versus bupropion randomized trial

Abstract

It is unclear whether anxiety increases or decreases suicidal risk. This may contribute to the lack of guidance on which antidepressant medications are best for suicidal depressed patients who present with high anxiety. This study explored whether anxiety predicts suicidal ideation in depressed individuals treated with paroxetine or bupropion. An 8-week double-blind trial comparing controlled-release paroxetine (N=36) versus extended-release bupropion (N=38) for effect on suicidal ideation and behavior in depressed patients with suicidal ideation, past attempt, or both found an advantage for paroxetine, but anxiety effects were not investigated. This secondary analysis explored the relationship, measured at baseline and weekly, of anxiety with suicidal ideation. Anxiety severity measured weekly correlated with suicidal ideation severity irrespective of treatment (P=0.012). Patients with high baseline anxiety showed a trend toward faster reduction of suicidal ideation with paroxetine compared with bupropion treatment (standard P=0.047; bootstrap P=0.077). The latter finding, if confirmed in larger samples, could enhance choice of antidepressant medication for suicidal, depressed patients presenting with high levels of anxiety.

FIGURE 1

Beck Scale of Suicidal Ideation mean score by study week in suicidal, depressed subjects at highest quartile of baseline HDRS anxiety factor randomized to controlled-release paroxetine or extended-release bupropion¹. ¹Predicted difference in SSI score between groups = 4.36 (SE=1.71) points lower, on average, with paroxetine compared to bupropion (assumes baseline HDRS Anxiety factor at highest quartile median=7; p=0.010; bootstrapped p=0.055; based on fitted reduced model using all subjects' data). Error bars are SEM.