Time-Dependent Effect of Hydrocortisone Administration on Intertemporal Choice

Abstract

Intertemporal choices, involving decisions which trade off outcomes at different points in time, are often made under stress. Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, resulting in the release of corticosteroids. Recent studies provide evidence that corticosteroids can induce rapid non-genomic effects followed by slower genomic effects that are thought to modulate cognitive function in opposite and complementary ways. It remains unknown, however, how corticosteroids affect intertemporal choice. To target time-dependent effects of cortisol on intertemporal choice, we randomly assigned healthy men to one of three possible groups: 1) receiving 10 mg hydrocortisone 195 minutes (slow cort) or 2) 15 minutes (rapid cort), or 3) placebo at both times, before measuring intertemporal choice by offering subjects decisions between small rewards available sooner vs. large rewards available later, in a double-blind design. We demonstrate a time-dependent effect of cortisol administration on intertemporal choice: when tested 15 minutes after hydrocortisone administration, subjects showed a strongly increased preference for the small, soon reward over the larger, delayed reward. In contrast, this effect was not found when testing occurred 195 minutes after hydrocortisone administration. Together, these results suggest that the physiological effects of acute, but not delayed, stress may increase temporal discounting.