I purchased the necklace
 for my son (he will be 4yrs old in June) hoping that it would help him a
 little. He was having issues with all three domains: Inattention, 
hyperactivity, and impulsivity. Let me tell you, I didn't realize how 
bad he had gotten until we had the necklace. We've only had the necklace
 for 2 and a half weeks, but it's like night and day. He obeys and 
follows through with most tasks, we have less issues with his 
hyperactivity (but some of that is normal for his age) and he is doing 
so much better with controlling his impulses. My mom was super skeptical
 about it, but even she says it's helping.