I've suffered from depression, and have relapsed into it a couple of times already and I'm only 23. It all started out when I was getting stomach pains, eating made me feel ill etc. Kept going forwards and backwards with GPs/consultants, until one day I was able to see my normal GP who had been off for a very long time. As soon as he saw me and all the notes he was able to tell it was depression.
The awareness was the main factor that helped me recover from it, but until that happens it's hard to realise that it's actually your mind causing these issues within your body which aren't really there. I'm still on Citalopram now, but that's for severe anxiety which stemmed from depression, I've been through CBT but it's been part of me since around when I was 19 so it's extremely hard to shift. I know what's going on, I know the body process of anxiety/panic attacks, but as of yet it's hard to find the actual trigger. It comes on at any time, it's a massive pain in the arse, neither are nice to go through, but anxiety is bloody awful.