In the United States, 1.5 million people abuse cocaine leading to a host of negative health and economic consequences, yet no FDA approved treatment exists. To develop effective treatments, the following must be considered: 1) do potential medications ameliorate brain disruptions associated with cocaine use? 2) are multiple, targeted treatments necessary? To meet these goals, innovative multi-modal neuroimaging will be used to determine whether rebalancing the serotonergic (5-HT) system reduces cocaine cue reactivity, impulsivity, and normalizes related neurochemistry and brain connectivity.