My 16 year old brother was just prescribed antidepressants

I'm worried about my brother who has been having depression. Something happened 2 years ago (he won't say) that has been bothering him. He recently started going to see a counselor who referred him to a psychiatrist who obviously prescribed an antidepressant. He has not started on it yet. He has lost about 50 pounds (he is overweight), his grades went from A's to E's and his motivation to do things has diminished (even things he likes to do like play games). I am desperately searching for some natural things he can try first but I'm so overwhelmed and frustrated because there is just too much conflicting info. My recommendations were going to be some supplements by Dr. Sandra Cabot like Depression Free (it is 5-HTP with B vitamins), Livatone Plus (for cleansing the liver), Fibertone, and some other things like probiotics, Omega-3's, digestive enzymes, amino acids (like Braggs liquid aminos) and a multivitamin/multimineral, and extra vitamin C along with fresh air, sunshine, exercise, fresh juices and whole foods. I don't know now after reading about 5-HTP and B6 not being so great and the glutamic acid issue. He does have asthma (since he was 6 months old) and is on daily Advair. He said that certain foods make him feel like crap, like pizza. I'm sure he's been on Antibiotics and he eats the standard American diet. My thinking is that he has Candida/leaky gut. What should I do??!! Do my recommendations sound ok or should I change them up a bit? Thank you!!

Nicole