As a kid coming fresh out of a similar phase at 18, now 22 I might be able to provide some insight from my self reflection. First off if your kid is medicated

As a kid coming fresh out of a similar phase at 18, now 22 I might be able to provide some insight from my self reflection. First off if your kid is medicated especially with high dose ADHD medication it is likely way over prescribed, and to deal with the literal mental overclocking storm the best way is to have an environment and stimuli you have complete control over, IE a computer in a room. Secondly as somebody else mentioned the child has likely been emotionally neglected, not only by their parents but by their peers. Its very hard to fit in these days and with social media it is overly apparent when you do not. Looking back the best thing that helped me claw my way out of the funk caused by this is most importantly that I wanted to, and secondly that my parents cared enough to try and involve me in social programs. One of the blessings of being young is that when you are forced into situations by your parents such as clubs or social circles, you have no need to justify being there. It sucks at first but it really helps. Also if theyre obese A health coach would be a great first step. If the young adult is defiant and very hard headed, forcing them to get a job will likely not work, but if theyre just soft getting them a job where they work with others is a great way to foster social intelligence. TLDR: If theyre from a rough and emotionally neglected background, be tender and encourage growth. If theyre from an easygoing and supportive background, be harsh and force them to grow.