The impact of neural emotion reactivity and regulation on the association between depression and suicide ideation in high-risk adults

Depression is closely related to suicidal ideation (SI); however, it is unclear who is most vulnerable to SI within the context of depression. Research suggests that individual differences in emotion reactivity and regulation may be potential moderators of the link between depression and SI. Therefore, the current study tested this hypothesis using objective markers of emotion reactivity and volitional cognitive regulation capacity during functional magnetic resonance imaging (fMRI). Adults (n = 91) with active SI completed validated self-report measures of current depressive symptoms and SI severity. Participants completed an fMRI task designed to probe neural response to aversive stimuli and during cognitive reappraisal – a form of volitional emotion regulation. Activation of the amygdala during aversive emotion reactivity was measured. Activation of ventrolateral, dorsolateral, and dorsomedial prefrontal cortex (vlPFC, dlPFC, and dmPFC) during cognitive reappraisal were also measured. A series of hierarchical linear regressions testing the unique and interactive effects of depression symptoms and neural activation on severity of SI were conducted. Analyses revealed a depression x amygdala activation interaction. The positive association between depression and SI severity was more robust in the context of high amygdala reactivity than low amygdala reactivity. Analyses also indicated there was no PFC activity (neural cognitive reappraisal) by depression interaction. Psychoactive medications were allowed and all participants endorsed suicidal intent. Strategies aimed at targeting exaggerated emotion reactivity within the context of depression may be beneficial.