I've certainly heard of dietary changes getting rid of depression, but it's usually pretty radical (vegan, gluten-free, all-local - all stuff that takes a lot of extra time, costs more, and/or takes a lot of getting used to). Herbal supplements can be helpful, especially if you can't afford to go to a doctor (I'm in the USA and see that often) but if you can, make sure to tell EVERY doctor EVERY medicine or supplement you use. And don't assume that they talk to each other! Your diabetes doctor or your arthritis doctor might send copies of your records to your psychiatrist, but that doesn't mean they're getting read. It's a good idea to keep a list of the medicines and supplements you take regularly in your wallet for quick reference.

St. John's Wort is often said to "neutralize" other medicines, but it's not quite that simple. It speeds up the cytochrome P450 enzyme pathway, which is the way many medicines are metabolized, and can cause the medicine to zoom right through your system so fast that it doesn't get absorbed properly. Here's a table that lists a bunch of things that affect and are affected by P450.

Love, Columbine