"Is it possible for ADD to become more prominent later in life than in the childhood years?"
by Larry Silver, M.D.
The behaviors of ADHD usually are apparent from early childhood. However, ADHD usually is not diagnosed until the behaviors (hyperactivity, inattention and/or impulsivity) begin to cause difficulties. For example, a child might be inattentive from age two or three but might not be identified as ADHD until the third grade when the inattention causes difficulties doing class work or homework. A hyperactive boy might be seen by his parents as being "all boy" until the child reaches first or second grade and a teacher suggests that the behavior is not in the normal range.
Some adults report that they had problems throughout their school years and beyond. However, they were not diagnosed until, as an adult, they read something that made them suspect ADHD or their child was diagnosed with ADHD and they realized what they had been living with. Therefore you are correct; it is possible for ADHD not to be recognized until later than early childhood.