Can Feeling Too Good Be Bad? Positive Emotion Persistence (PEP) in Bipolar Disorder

Positive emotions are vital to attaining important goals, nurturing social bonds, and promoting cognitive flexibility. However, one question remains relatively unaddressed: Can positive emotions also be a source of dysfunction and negative outcomes? An ideal point of entry to understand how positive emotion can go awry is bipolar disorder, a psychiatric disorder marked by abnormally elevated positive emotion. In this review I provide an overview of recent experimental evidence from individuals at risk for, and diagnosed with, bipolar disorder. I present a novel account of positive-emotion disturbance, referred to as positive emotion persistence (PEP), and consider potential mechanisms. The central thesis guiding PEP is that persistent activation of positive emotion across contexts and not solely in response to positive or rewarding stimuli is a marker of emotion dysfunction in bipolar disorder. I discuss implications for the study of bipolar disorder and positive emotion generally.