Improving Therapeutic Learning in Depression: Proof of Concept

Investigators will study the efficacy of DCS for augmenting therapeutic learning relevant for the treatment of depression (i.e., outside the extinction learning where DCS has been shown to have success). Specifically, the study investigates the role of DCS in enhancing declarative memory in depressed individuals, as evaluated by standardized tests and the retention of cognitive therapy session material. Investigators will also study an active comparison agent, modafinil, which appears to offer cognitive enhancing effects among both sleep-deprived and non-sleep-deprived individuals, but also appears to have drug-state (e.g., mood and side) effects that are not characteristic of DCS augmentation. Therefore, drug-context effects may affect memory retention over time. Hence, the study will evaluate memory enhancement effects both during the period of drug action as well as one week later when no drug is taken. Overall, investigators will examine cognitive function and memory performance over 4 study sessions in 96 men and women with major depression, who, in a double-blind fashion, will be randomly assigned to either: (1) 250mg DCS, (2) 100mg modafinil, or (3) placebo administered on Study Weeks 2 and 3. The memory tests include both items unique to a given study week and memory tasks that are repeated over time that allow assessment of memory and retention effects across one-week periods.