I wouldn’t recommend smoking ganja. It will just flat out dump him in an insidious depressive spiral and will be extremely difficult for him to claw out from. Marijuana exacerbates depression and anxiety in prone individuals especially with these modern hard sprayed strains. I come from the chronic strains of the early 2ks (og kush, grand daddy purps, train wreck, sour diesel, ak-47, northern lights, purple haze, LA confidential, blueberry, skunk, chocolate thai, white widow, cat piss, afghani kush etc etc). I am beyond smoked out. Now I can’t handle all this new smoke.
Dude needs to exercise get the blood flowing to the brain, sleep 7-8 hours tops and eat homemade cooked meals/h2o. If that doesn’t hack it then either check T levels or go to cognitive behavioral therapy/meds.