Hello Friend, Good that you are seeking a help here. Appreciate your interest to help your friend. Medicine are just one part of any psychic treatments and they also add side effects. So in parallel he needs to follow non medicine treatments like self therapies, lifestyle changes, excersise, dietary changes etc to completely overcome depression.
Consult a counselling psychological to evaluate his condition and recommend suitable treatment plan.
Next Steps
Consult a psychologists directly or online. Feel free to reach out to me online through Practo app chat for further evaluation and counseling support.