Though it’s called adult ADHD, symptoms start in early childhood and continue into adulthood.In some cases, ADHD is not recognized or diagnosed until the person is an adult. Adult ADHD symptoms may not be as clear as ADHD symptoms in children. In adults, hyperactivity may decrease, but struggles with impulsiveness, restlessness and difficulty paying attention may continue.

https://www.mayoclinic.org/diseases-conditions/adult-adhd/symptoms-causes/syc-20350878