The inverse relationship between social support and depression has been robust to a wide variety of conceptual replications with college, community, and clinical samples. However, there is inadequate understanding of the mechanisms by which social support protects against depression. In this paper, we define a subtype of social support, adaptive inferential feedback, which is more precise than the general concept of social support. We elaborate two possible mechanisms for the beneficial effect of adaptive inferential feedback on depression by incorporating this type of social support into a specific etiological model of depression, the Hopelessness Theory of depression. Empirical tests are conducted for the two hypothesized mechanisms by which adaptive inferential feedback protects against depression as well as the full expanded Hopelessness Theory proposed herein. Our results supported both the specific mechanisms proposed as well as the full expanded hopelessness theory. We found that adaptive inferential feedback predicts more positive inferences for stressful events and a more positive inferential style prospectively. It also interacts with cognitive risk and stress to predict future hopelessness and depressive symptoms as well as concurrent diagnoses of hopelessness depression over and above the contributions of stress, cognitive risk, and general social support which are known predictors of depressive symptoms and disorders. Thus, this newly defined subtype of social support may be an important contributor in the etiology of hopelessness depression.