OBJECTIVES: Expressed emotion (EE), or the presence of criticism/hostility/emotional overinvolvement in a family relationship, predicts poorer outcomes in bipolar disorder; however, the mechanism of this is unclear. The present study investigated whether, in a sample of young adults (aged 18-40 years) with bipolar disorder, parental criticism was associated with Behavioral Approach System (BAS) dysregulation, including emotional reactivity to negative feedback and cognitive schemas of self-criticism/perfectionism. METHOD: Twenty-two young adults with bipolar I disorder and 22 matched control participants completed an interview, questionnaires, and a computer-based task with false negative feedback; emotional reactivity to this feedback was assessed. RESULTS: Compared to control participants, clinical participants exhibited higher levels (p = 0.001) of self-criticism, and a trend towards a greater decrease in positive affect after negative feedback (p = 0.053), even when controlling for mood symptoms. Among clinical participants, perceived criticism from paternal caregivers was associated with self-criticism and perfectionism, and low perceived paternal care was associated with decrease in positive affect. CONCLUSION: Strain in parental relationships may be associated with BAS dysregulation for individuals with bipolar disorder.