When I worked and lived among the homeless in my young adulthood, I did learn that street alcoholism was always sourced in mental illlness, and later in life learned that vulnerability is greatly magnified by social isolation, disrupted sleep, seasonal affected disorder, and diet.
Getting a good nights sleep is a science which takes some study, I won’t go into that here. You could spend years figuring out how to sleep, and it would be worth the effort.
90% of church and AA is the social isolation relief. AA may run some people the wrong way, and it does carry a stigma.
I would prescribe searching for something that deeply interests the boy that has a social element. Any crazy thing will do. If it means buying him equipment or support, do it. Part of depression is being over inhibited to invest in our passions.
Speaking now as a person saved in the Evangelical sense, I would assert that God is not a fragile thing that must be defended by clinging to your specific faith, but rather God is a universal reality that can be discovered by many paths.
Specific insecure faith, can become a barrier to the young, an unintentional counter witness. There are many spiritual teachers in your town. Look for an opportunity to introduce your son to them, in case he clicks wth one and God has provided this for you. Visiting different churches is fun.
While never disavowing my Christianity, it was Shambala Buddhism which cured the misery of my 20’s. They are a sex crazed bunch, but no more so than any secular college experience.
Young people today are responding positively to the science based spirituality of Thomas Warren Campbell, a physicist connected to The Monroe Institute and the military remote viewing community.
If you are in the North or rainy coast, look for an opportunity to introduce your son to better weather. Many a life has been saved by a move to the sun belt.
Read up on mental illness and diet. As much as possible introduce him to home prepared foods that are plant centered and fresh. Seafood is correlated to positive emotions.
Regarding addiction, each person acquires an escape sequence from overwhelming emotions. For myself, my escape sequence was travel, workaholism, music, and religion. I had a healthy fear of chemistry and psychiatry.
So when my mind finally settled in my late twenties, I had a lot of education and strange experiences under my belt, with no addictions and no record of mental illness on my resume. All this to say, you can help your son construct an escape sequence other than the bottle.
Final note, many a person is kept in balance by a dog or two.
