if he has smoked or used something most of his life he may have an addictiove personality which is hard to overcome.....better to see realith and cut your losses...however. if stress has overtaken him recently I would suggest
KavaKava for mood elevation and he may want to combine it with gaba...whicvh will mellow him out. It won't feel the same as pot but it depends on what his real interest are..looking for temp help with stress or more interested in getting high.