Stereotypic movement disorder

Hey ladies has anyone son or daughter cousin nephew niece Etc been diagnosed with stereotypic movement disorder? My stepsons 12 and just got diagnosed a year ago my boyfriend said he's write a paragraph for the guy was older and said he enjoyed doing it when he was little do you think that's true or do you think he's lying just to not bring them to another doctor?

He usually does it when he plays a PlayStation which me and my boyfriend always argue about him playing due to him doing it so much that he almost can't even enjoy playing. He plays Minecraft Lego Batman Lego adventure Star Wars my boyfriend has recently been starting to play with him on the PlayStation and been letting him play Zombies which is whatever but where I live its summer and I think they should be outside more and he should be drawn away from the electronics to release some of his energy being he does have ADHD any advice on what to do do you think. do you think he shouldn't

Thanks for your help in advance one concern stepmom