Given evidence of divergent cortisol patterns in ASD vs. ADHD (i.e. enhanced cortisol responses to stress in ASD53, and attenuated cortisol profiles in ADHD54, 55), it would follow that an OXTR variant leading to increased cortisol activity would be disadvantageous in ASD, but potentially advantageous in ADHD. The gene discussed is OXTR; the disease is attention deficit-hyperactivity disorder.