BackgroundBipolar disorder type I (BD-I) is associated with emotion dysregulation. However, experimentally controlled studies of emotion regulation (ER), particularly those examining the brain correlates of the putative deficits, are scarce and their results inconsistent.MethodNineteen euthymic BD-I patients and 17 healthy controls (HC) underwent functional magnetic resonance imaging while performing a visual ER 2 × 2 factorial task, with instruction (Look or Decrease) and valence (Negative or Neutral) as within-subject factors. Emotional ratings were collected after each picture presentation to assess regulation success.ResultsBD-I patients were successful at downregulating their emotions, although to a lesser degree than HC. Both groups engaged brain regions previously implicated in ER; however, unlike HC, patients engaged some of those regions, particularly the ventrolateral prefrontal cortex (VLPFC) in the Negative Look and Neutral Decrease conditions. Moreover, patients failed to show the reduced amygdala activation in the Negative Decrease condition observed in HC.ConclusionOur findings suggest that BD-I patients are able to downregulate their emotions when instructed to do so. However, they also appear to engage their ER network, particularly the VLPFC, even when not required to do so. These findings may help explain their often-reported difficulty in regulating emotions in everyday life despite their attempts to do so.