Dopaminergic D₁ Receptor Stimulation Affects Effort and Risk Preferences

Activation of D₁ receptors has been related to successful goal-directed behavior, but it remains unclear whether D₁ receptor activation causally tips the balance of weighing costs and benefits in humans. Here, we tested the impact of pharmacologically stimulated D₁ receptors on sensitivity to risk, delay, and effort costs in economic choice and investigated whether D₁ receptor stimulation would bias preferences toward options with increased costs in a cost-specific manner.

In a randomized, double-blind, placebo-controlled, parallel-group phase 1 study, 120 healthy young volunteers received either placebo or 1 of 3 doses (6 mg, 15 mg, or 30 mg) of a novel, selective D₁ agonist (PF-06412562). After drug administration, participants performed decision tasks measuring their preferences for risky, delayed, and effortful outcomes.

Higher doses of the D₁ agonist increased the willingness to exert physical effort for reward as well as reduced the preference for risky outcomes. We observed no effects on preferences for delayed rewards.

The current results provide evidence that D₁ receptor stimulation causally affects core aspects of cost-benefit decision making in humans.