Homeopathy is wonderful for treating depression. It's effective and also safe and inexpensive. A consultation with a homeopath is necessary so that the most correct remedy can be chosen for your friend. Homeopathy is preferable to anti-depressants which have been shown to have serious side effects. Studies also show that anti-depressants only work by placebo.
If you google homeopathy Depression you will find a lot of information about it and also case records of people who have used it successfully.