ADHD can be diagnosed as early as four years of age, though clinical experience suggests waiting until closer to school age for a more stable diagnosis.

“with ADHD um you can make a diagnosis as young as four years of age uh but again I'll just tell you from my clinical experience I rarely jump onto the diagnosis at with a four or five-year-old because they're still a moving Target although I may start interventions like behavioral interventions and parenting support um but there are a lot of four-year-olds who are pretty busy um so I generally way closer to school age although technically you can make it as young as four”