I found the opposite. It was mumsnet that helped me find out I had a massive candida problem. I'd been given a huge dose of antibiotics after a miscarriage, then about 6 months later, after gradually getting mild thrush more and more each month just before my period, I started to feel really really low. Exhausted all the time, and kind of depressed and almost removed - distant.
I thought I had a thyroid problem. I had two lots of blood tests, nothing...then finally looked up my symptoms and found out about candida. Mumsnet mentioned candida.free.co.uk and the woman running that website, def. not a quack was so helpful. I ended up changing my diet, I had been craving sugar and bread etc...and I got some Threelac, and I swear it turned around in a week. It was like a huge depressing veil had been lifted. I told my GP when I'd sorted it, thinking they might want to know, but absolutely not interested.
They do know it's a real thing with terminally ill patients...though.
I would do the spit test, and if you do have thrush at all, there is every chance you've got a bit of a problem with it. Just look at candida.free.co.uk as well...very helpful questionnaire on there. And you can phone the woman, she is not into selling you stuff you don't need.
I know it's a real thing because I had it.