Around 3-5% of children have ADHD, which has three main types - inattentive, hyperactive, and combined. Symptoms include excessive talking, fidgeting, interrupting others, and difficulty waiting turns. Boys are more likely to have ADHD than girls. While there is no known cause, research links it to less activity in brain regions controlling impulses. Treatments include behavior modification and medications like Ritalin. Parent resources include books, support groups, and online communities.