BackgroundSuicidal thoughts and behaviors (STBs) are common among adolescent girls and increase risk for suicide death. Emotion regulation difficulties are linked with STBs, particularly in response to targeted social rejection. However, neural correlates of this link have not been investigated and may identify novel targets for interventions. Here, we examined neural correlates of emotion regulation before and after an experimentally delivered targeted social rejection in adolescent girls with STBs and girls without STBs (i.e., control participants). MethodsGirls (N = 138; age range, 9–15 years; mean [SD] age = 11.6 [1.79] years) completed a functional neuroimaging emotion regulation task. In the middle of the task, participants were socially rejected by an unfamiliar confederate whom the participants had elected to meet. Participants also completed a multimethod STB assessment. ResultsBefore rejection, girls with a history of STBs, compared with control participants, showed greater activation in the right superior frontal gyrus when passively viewing negative stimuli, and girls with suicidal behavior (SB) versus those without SB showed less activation in the right frontal pole during emotion regulation attempts. Following the rejection, girls with STBs, compared with control participants, showed greater activation in the right inferior frontal gyrus during emotion regulation. ConclusionsBefore social rejection, girls with SB versus without SB may not activate brain regions implicated in emotion regulation, suggesting a vulnerability to poor regulation at their baseline emotional state. After social rejection, girls with any history of STBs showed altered activation in a brain region strongly associated with inhibition and emotion regulation success, possibly reflecting increased effort at inhibiting emotional responses during regulation following stress exposure.