Learning and memory play a central role in emotional disorders, yet clinical theory has not incorporated recent advances in episodic memory literature. In Chapters 1 and 2, I present a new, transdiagnostic theory of how memory and mood interact in emotional disorders (Cohen & Kahana, 2022). Drawing upon Context Maintenance and Retrieval (CMR) models of episodic memory, I propose that memories form associations with the contexts in which they are encoded, including emotional valence and arousal. Later, encountering contextual cues retrieves their associated memories, which in turn reactivate the context that was present during encoding. I first show how our retrieved- context model accounts for findings regarding the organization of emotional memories in list-learning experiments. I then show how this model predicts clinical phenomena, including persistent negative mood after chronic stressors, intrusive memories of painful events, and the efficacy of cognitive-behavioral therapies. In Chapter 3, I validate this theory in two independent samples of individuals with clinically significant major depressive disorder (MDD), generalized anxiety disorder (GAD), and nonclinical controls. Using ecological momentary assessment, participants in both samples reported their emotional responses to one week of daily events. Computational modeling with the CMR model developed in Chapters 1-2 confirmed the presence of an "emotional context effect" in which the emotional effects of prior events lingered and influenced participants’ emotional responding to new events. A context of recent negative events blunted the positive emotion felt after a new positive event, and worsened the negative emotion felt after a new negative event. A context of recent positive events buffered against the negative emotion felt after a new negative event, and amplified the positive emotion felt after a new positive event. A faster rate of updating for negative, but not positive, emotional context correlated with heightened MDD and GAD severity. Perseverative thinking accounted for these relationships, perhaps by refreshing and reinforcing negative mental context. This work demonstrates that contextual memory processes may guide (mal)adaptive responding to new stressors and positive events in emotional disorders.