Neural predictors of treatment outcome through emotion regulation in internalizing disorders: a narrative review.

Internalizing disorders such as depressive and anxiety disorders are prevalent, disabling, and characterized by difficulty managing emotions particularly in the context of negative information. Despite the availability of empirically supported treatments, response to these treatments remains heterogeneous. Accruing data indicate neural predictors of treatment response have the potential to contribute to precision medicine to improve treatment outcomes. This review evaluates functional magnetic resonance imaging studies that examined explicit (e.g., effortful) and implicit (e.g., automatic) emotion regulation involving negative stimuli and treatment response. Results showed treatments mostly consisted of cognitive behavioral therapy, exposure therapy, and/or pharmacotherapy. Explicit regulation findings were predominantly based on cognitive reappraisal, which showed pre-treatment activity in medial and lateral prefrontal cortices frequently served as predictors of treatment response. Regarding directionality, greater symptom improvement was generally associated with lower baseline activity in these regions. Results suggest patients with less baseline explicit regulation capacity may benefit more from treatment. For implicit regulation, most studies utilized emotional interference tasks. Predictors frequently involved prefrontal cortical regions and anterior cingulate cortex; here, the direction was largely that of more baseline activity predicting greater symptom improvement. Findings suggest treatment may leverage greater pre-existing implicit regulatory capacity. While baseline activity in other regions during explicit and implicit regulation were reported, including regions central to emotion processing (e.g., amygdala), results were less consistent. Despite these insights, substantial gaps in the literature were observed. For explicit regulation, studies predominantly focused on cognitive reappraisal, an adaptive regulation approach. Furthermore, the majority of studies consisted of major depressive disorder, anxiety disorders, and posttraumatic stress disorder with insufficient representation of other internalizing disorders. Findings underscore the relevance of neural predictors of treatment outcome through emotion regulation in internalizing disorders. However, further study is needed to determine their contribution in precision medicine.