Association of orexin/hypocretin receptor gene (HCRTR1) with reward sensitivity, and interaction with gender.

•Orexins are involved in the regulation of both reward and stress response.•The HCRTR1 rs2271933 G > A genotype is associated with aggressiveness.•The more aggressive A/A homozygote males have high reward sensitivity.•Insatiability by reward, not openness to rewards is associated with aggressiveness.•Only in the A/A homozygotes aggressiveness is associated with openness to rewards.