Clinical Research Studies

Mood disorders are characterized by a tendency to subjectively evaluate objectively positive outcomes in a negative light. A fundamental feature of nearly all standard models of decision-making is the idea that the subjective value of any choice option is shaped by a psychological and neurobiological variable called the reference point. The reference point serves as an internal benchmark against which values of all possible future events are weighed. Whether any given activity is viewed as an improvement or decrement in the quality of life is determined by whether that activity yields an outcome evaluated as better or worse than the reference point. Using behavioral decision-making tasks informed by an understanding of how human expectations are set, the investigators propose to test the hypothesis that affective mood impacts the decision-making reference point—the computational instantiation of our expectations—and thus drives shifts in subjective value that mark mood pathologies like major depressive disorder (MDD). The core hypothesis of this study is that the affective changes associated with MDD can be largely captured as a pathological over-setting of the neurobiological reference point, such that nearly all activities appear as undesirable outcomes that lie well below the pathologically high reference point mark.