If ADHD is genetic, why hasn’t evolution ‘removed’ it?

This question actually comes up a lot in research discussions, and it is not nerdy at all. From an evolutionary standpoint, ADHD traits make sense. Evolution does not select for modern success or comfort. It selects for survival and reproduction. Traits linked to ADHD, such as novelty seeking, rapid responsiveness, high energy, risk tolerance, creativity, and scanning for change, would have been advantageous in unpredictable or dangerous environments. These traits support exploration, hunting, migration, innovation, and quick reaction to threat. ADHD is also not caused by a single gene. It reflects many genes that influence dopamine regulation and attention. These genes exist on a spectrum across the population. In moderate expression, they may enhance adaptability and problem solving. Even in higher expression, traits can be beneficial in the right context. Because these genes are not universally harmful, they are not selected out. What has changed is the environment. Modern life demands sustained focus, delayed reward, paperwork, time abstraction, and sitting still for long periods. These are historically new pressures. Traits that once fit well now clash with rigid systems, making differences look like deficits. Clinically, ADHD is understood as a context dependent condition. The traits persist because they are part of normal human variation, not because evolution failed. They become impairing when environments narrow what kinds of brains are allowed to function well.