Our youngest child is 18 months old and came to us already treated, so children can show symptoms early.
The looks of the disorder are different across age and gender.
We wouldn't interfere with infants or toddlers unless their behavior interfered with functioning, for example, if they were really aggressive. Most can do fine until ... they're around other children.
Some work beautifully for some children but not for others. We don't know what works for what child ahead of time. There are lots of things to try, including non-medication treatment.
Some day, it might be possible to prevent (ADHD), but that requires genetic research, which now is in its infancy. Now, we can prevent the worsening of conditions with effective intervention, but we cannot prevent the condition.
Anxiety disorders, depression can cause the same appearance of the same symptoms (as ADHD), but you have a whole different reason for these, so treatment is dramatically different.
Medication will help reduce some symptoms, but taking medication over time won't eliminate them. We can't say if you take this drug for five years, (the problem) will go away. We can't predict what will happen.
I don't think you can make a child have ADHD. A child is born with a predisposition, and the environment will make or break that predisposition.
The frontal lobe of the brain, which controls these behaviors, matures until age 21. As children mature, some symptoms get better -- though they don't grow out of ADHD, as used to be believed, and half need treatment into adulthood.
