An active inference approach to interpersonal differences in depression

Depression is characterized by different distortions in interpersonal experience and behavior, ranging from social withdrawal to overt hostility. However, clinical psychological research has largely neglected the need for an integrative framework to operationalize these different phenomena and their dynamic change more accurately in depression. In this article, we draw on active inference theory, a comprehensive theory of perception, action, and learning, to provide a formal model explaining how variations in patients' internal belief-systems lead to differences in social experience and behavior. In this context, we assume that individuals cannot directly grasp the characteristics of their social environment. Instead, they must infer them indirectly from ambiguous social observations, which they themselves generate and alter through their actions. Differences in interpersonal experience and behavior arise from the interplay of patients’ prior expectations, their propensity to infer particular social states from certain observations, and their beliefs in their ability to influence these situations through specific actions. We then use concrete examples to demonstrate how future research can take our approach to identify systematic differences in interpersonal experiences and behaviors among depressed patients (or patient subgroups) and to investigate their changes in response to new social experiences. We also discuss potential applications of our approach in diagnosing and treating depression. This work is a move towards understanding the interpersonal aspects of depression in more detail, recognizing their importance in etiology, diagnosis, and treatment.