Neural responsiveness to reward and suicidal ideation in social anxiety and major depression before and after psychotherapy

Suicidality is prevalent in Social Anxiety Disorder (SAD) and Major Depressive Disorder (MDD). Limited data indicate the reward positivity (RewP), a neurophysiological index of reward responsivity, and subjective capacity for pleasure may serve as brain and behavioral assays for suicide risk though this has yet to be examined in SAD or MDD in the context of psychotherapy. Therefore, the current study tested whether suicidal ideation (SI) relates to RewP and subjective capacity for anticipatory and consummatory pleasure at baseline and whether Cognitive Behavioral Therapy (CBT) impacts these measures. Participants with SAD (n = 55) or MDD (n = 54) completed a monetary reward task (gains vs. losses) during electroencephalogram (EEG) before being randomized to CBT or supportive therapy (ST), a comparator common factors arm. EEG and SI data were collected at baseline, mid-treatment, and post-treatment; capacity for pleasure was collected at baseline and post-treatment. Baseline results showed participants with SAD or MDD were comparable in SI, RewP, and capacity for pleasure. When controlling for symptom severity, SI negatively corresponded with RewP following gains and SI positively corresponded with RewP following losses at baseline. Yet, SI did not relate to subjective capacity for pleasure. Evidence of a distinct SI-RewP association suggests RewP may serve as a transdiagnositic brain-based marker of SI. Treatment outcome revealed that among participants with SI at baseline, SI significantly decreased regardless of treatment arm; also, consummatory, but not anticipatory, pleasure increased across participants regardless of treatment arm. RewP was stable following treatment, which has been reported in other clinical trial studies.