The effect of sex hormones on decision-making in healthy young women

Abstract

Risky decision-making is associated with several mental health disorders and deleterious health behaviours. As men are known to engage in riskier behaviours, the effects of testosterone on decision-making have been extensively studied. However, few studies have been conducted in women and by extension, examined female sex hormones (progesterone and estradiol). This study aimed to understand the role of sex hormones (progesterone, estradiol, and testosterone) on decision-making. Forty healthy young women provided saliva samples to assess their sex hormones before completing the Iowa Gambling Task. The goal of this decision-making task was to maximize monetary profits by drawing cards from four decks: two with large gains and larger losses (risky decks) and two with small gains and smaller losses (safe decks). For the purposes of data analysis, card draws were separated into five blocks of 20 draws each, allowing us to quantify the learning rate of the advantageous safe decks. Multilevel linear models revealed two inverse interactions: time*testosterone and time*progesterone. Specifically, lower levels of progesterone and higher levels of testosterone were independently associated with riskier decision-making. In both cases, this effect led to slower learning of the advantageous safer decks. These data suggest that the effects of testosterone on risk-taking are not unique to men. Moreover, the results suggest that progesterone also influence risk-taking. This raises important questions regarding risk-taking tendencies in women throughout the menstrual cycle (which induces endogenous hormonal variations) and in women using hormonal contraceptives (which dampen the menstrual cycle).