I think if he is 18, that is considered no longer a minor, and parents cannot force him into any medical intervention, legally, or receive results because of HIPPA (unless he gives permission).

IMO the "work ethic" begins before 18. Attitude towards responsibility and saving money, earned, starts much earlier.
My son was on a work program from high school before he was 16, and worked in the local library, as his first job. Also on our vacations a substantial amount of work needs to be done, and he learned quite a lot from those chores!

Also a factor-- video games. Many many young people today are really hooked on these. That can interfere with life in general when it gets extreme!

Drugs cost money... where would he get that, if he is not working?