Immune System Gene Linked to Hyperactivity, ADHD and Autism Researchers have identified a link between the immune system and hyperactive behaviors, highlighting the role of the STAT1 gene in regulating behavior. STAT1, a key regulator in immune responses, appears to influence brain development and function, particularly in dopamine neurons responsible for learning, memory, and motivation. In mouse studies, prolonged activation of STAT1 during embryonic development led to hyperactivity, fewer neurons, and reduced neural activity in critical brain regions. The findings suggest that disruptions in STAT1 signaling may contribute to neurodevelopmental disorders like autism and ADHD. Researchers are now exploring whether the STAT1 pathway could be targeted for future therapies.