First of all i dont really thing not going out to meet friends leads to depression, most of us are raised in a restricted area by strict parents. It only becomes a problem when u allow it to become a problem so you are gonna have to tell him to find things to do at home uk like helping out with chores ,studying (it doesnt have to be school stuff he can also read some fictions), listen to songs,sleep,organize his bedroom,trying to build a better relation ship with his parents by talking and generally being helpful with what they do around the house and many many other things. I mean cmon he doesnt have to go out and meet friends to be a healthy person he can do infinite productive things at home alone.