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Risk taking is an integral part of learning and development, particularly during adolescence the prevalence of risky behaviors peak. It is hypothesized that the tendency to take risks is related to pubertal maturation, where there is interplay between gonadal hormones, the neural mechanisms that underlie affective (e.g., reward) processing, and risky behavior. To test this hypothesis, fifty healthy adolescents (aged 10-16 years; 33 girls, 17 boys) at different stages of puberty performed a gambling task while lying in the MRI scanner, and provided saliva samples for hormone assessment. Gonadal hormone levels were correlated with the neural response to receiving a monetary reward. Results showed that testosterone level correlated positively with activation in the striatum for both boys and girls, suggesting that individual differences in hormones at puberty are related to the way adolescents respond to reward, which can ultimately affect risk-taking behavior.

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Neurobiological models suggest that adolescents are driven by an overactive ventral striatum (VS) response to rewards that may lead to an adolescent increase in risk-taking behavior. However, empirical studies showed mixed findings of adolescents' brain response to rewards. In this study, we aimed to elucidate the relationship between reward-related brain activation and risky decision-making. In addition, we examined effects of age, puberty, and individuals' reward sensitivity. We collected two datasets: Experiment 1 reports cross-sectional brain data from 75 participants (ages 10-25) who played a risky decision task. Experiment 2 presents a longitudinal extension in which a subset of these adolescents (n = 33) was measured again 2 years later. Results showed that (1) a reward-related network including VS and medial PFC was consistently activated over time, (2) the propensity to choose the risky option was related to increased reward-related activation in VS and medial PFC, and (3) longitudinal comparisons indicated that self-reported reward sensitivity was specifically related to VS activation over time. Together, these results advance our insights in the brain circuitry underlying reward processing across adolescence.