Pretty sure he was talking about homeopathy.. which I agree with him on.. It's a dangerous practise which holds no benefits outside of placebo.
I looked up what homeopaths use to treat "depression" (I put in inverted comma's as they don't seem to have quite grasped that momentary upset and depression are two very separate things)
www.netdoctor.co.uk/diseases/depression/homeopathy_000066.htm
I suggest you ask your homeopath what it is they give you and see if your depression may, in some part, be due to a certain mineral or vitamin deficiency found in things listed in that link.
That would be all well in good if they didn't put the "essence" of it into a tank of water, then taking a drop out of that tank and putting into another tank of water, and so on, with the belief that this makes it stronger!? (they can do this up to 400x) to effectively sell people nothing but sugar pills (by the final treatment, most of the time, there wouldn't be a molecule left of the "healing product", making it; Water)..
They then try to sell this idea that water has a memory, which is how it passes on it's healing qualities (still not explaining why more dilution = better).. This is simply bollocks and has been proven to be bollocks. The final product in homeopathic strengthening of medicine is water.. Good ol H2O.
Did you know they did this to "strengthen" their medicine? Did you know that there is not a single atom left from the original product in the final product? I doubt they even bother with the original product.. they know it's just going to be lost and they're gonna end up selling water soaked sugar pills.
How much do they cost these days?
Ask your homeopath where they studied medicine, or even biology.. Quacks.