The value of an object or state is not simply reflected in the brain as an intrinsic property of that object but dynamically constructed by integration of its constituents within complex interrelated homeostatic, motivational, and social contexts. The desired objects are often not available for immediate use requiring an effortful action or sets of actions to acquire them. Such a value-based or reward-seeking action is executed with a vigor proportional to how much the desired object is wanted and often involves applying specific decision-making strategy or policy. After obtaining, the consumption of or interaction with the rewarding object can result in a hedonic or pleasurable experience that by itself functions as a reinforcer for the repetition of the same executed action. Impairment in any of these process (value construction, value-based decision-making, or action execution) can result in challenging and often difficult-to-treat neuropsychiatric symptoms such as apathy, amotivation, impulsivity, compulsivity, or anhedonia. By taking a Systems Neuroscience approach at the brain large-scale network level, we aim to explore the circuit-based neurocomputational mechanisms of aberrant valuation and value-based decision-making in psychiatric conditions in which those processes are known to be impacted such as obsessive-compulsive disorder, major depressive disorder, and anorexia nervosa, with the ultimate aim of developing novel and more effective treatments.