Soutschek A, Gvozdanovic G, Kozak R, et al. - Researchers examined how pharmacologically stimulated D₁ receptors influence sensitivity to risk, delay, and effort costs in economic choice. Further, they investigated whether D₁ receptor stimulation would bias preferences toward options with increased costs in a cost-specific manner. They conducted a randomized, double-blind, placebo-controlled, parallel-group phase 1 study including 120 healthy young volunteers and administered them either placebo or 1 of 3 doses (6 mg, 15 mg, or 30 mg) of a novel, selective D₁ agonist (PF-06412562). The willingness to exert physical effort for reward increased and the preference for risky outcomes decreased in correlation to the receipt of higher doses of the D₁ agonist. No effects on preferences for delayed rewards were observed. Findings thereby support the causal effects of D₁ receptor stimulation on core aspects of cost-benefit decision making in humans.