ADHD affects about 5% of people and stems from differences in how the brain develops focus, planning, and self-regulation. It is not a matter of willpower. Helpful patterns include reminders for unfinished drafts, chunked long forms, gradual disclosure of options, and visible progress, while autoplay and infinite scroll are best avoided. ADHD often overlaps with autism, dyslexia, and anxiety, so designing for it tends to help several groups at once.