Hi troubles
Your son is so blessed to have you in his corner, fighting for the kind of life you want for him and the kind of life he deserves.
While the traumatic loss of his friend would have been an obvious reason for his spiral into depression (I feel so deeply for him, given his loss), what's followed that might help explain some of the added struggles he could be facing at this stage. While he may not be open to talk therapy with a psychologist or medication and things along those lines, I'm wondering whether it could make a difference if you approach him from the perspective of 'A depressing lack of energy'. Maybe starting things with what's easiest could be the way to go, not sure.
Blood tests, to check for chemical imbalances like B12, iron, thyroid etc could be one thing. Ordering an at home sleep study (to cross sleep apnea off the list) could be another. As a 53yo gal who's put on a bit of weight over time, I can tell you sleep apnea can become a major energy zapper which can lead to depression. A depressing lack of energy that can come about for a variety of reasons, trauma included, can entail an holistic kind of detective work and recovery. If your son doesn't want to approach things from a mental perspective or a soulful one, a purely physical one could prove to be the first step on the path to recovery and reformation.
Again, he's so blessed to have you as a light and a guide in his life.
