The ability to adaptively exert control over negative emotions is associated with beneficial mental health outcomes. Less is known about the associated emotional sequelae surrounding controllable versus uncontrollable positive emotional experiences. The ability to harness positive emotions is of particular importance in populations involving disrupted positive emotion functioning. In the present study, participants engaged in a relived memory task in which they recalled either a controllable or uncontrol- lable past positive emotional experience in counterbalanced order, while concurrent experiential and autonomic responses were measured. Participants included adults with bipolar I disorder (BD; n = 32), major depression (MDD; n = 32), and or nonpsychiatric controls (CTLs; n = 31). Across all participants, reliving a controllable positive emotion experience was associated with exhibited increased respiratory sinus arrhythmia, an autonomic marker of regulatory control. Interestingly, only the MDD group reported increased positive emotion and decreased cardiovascular arousal when reliving an event involving uncontrollable positive emotion, compared to the BD and CTL groups. No other group differences emerged. These findings suggest that although controllable positive emotion experiences may be adaptive for most, individuals with a history of restricted affect and depressed mood may actually derive more pleasure from times of unharnessed happiness.