Identity disturbance (ID) has been identified as a transdiagnostic contributor to psychiatric symptoms and seems to be comprised of both interpersonal and self-oriented mechanisms. This study developed the identity self-focus experimental task, incorporating personalized adjectives, reflection, and varying conditions by source (Self or Other) of identity adjectives, to better understand the relation between ID and affectivity. University students ( N=97) completed a positive mood induction followed by the experimental manipulation— during which they continuously rated their positive affect. Results implicated specific facets of ID in higher negative and lower positive affect, and ID predicted difficulty regulating positive emotions. Higher ID was also associated with difficulty maintaining consistent positive affect for those in the Self condition and was associated with poorer emotion regulation for those in the Other condition. Findings suggests that ID is implicated in an unhelpful cognitive and affective style, especially for those with high levels of ID. While evidence-based treatments either do not or only indirectly address identity functioning issues, results suggest that measurement of ID and targeted intervention to strengthen identity may support emotional health outcomes of therapeutic treatments.