What could be the possibilities of what's wrong with me?

Just one other possibility. I'm assuming you've seen your GP about this and been examined, including full blood tests. Sudden mental changes can sometimes be the result of physical illness, so you should always start with a general check-up. It looks as if you're still in the right age range to be susceptible to infectious mononucleosis (glandular fever). This can sometimes cause what seem to be psychiatric symptoms in the aftermath, especially among young people. There's also the possibility of some kind of neurological condition.

I'm sure you'll end up getting the help you need. Don't despair.

Alternatively, is your arthritis part of a more generalised auto-immune syndrome? Flare-ups of some of these conditions can cause extreme fatigue, occasionally with similar mental symptoms to the ones you're describing.

I've had a recent experience with the latter myself. I have Sjogren's syndrome, an auto-immune condition which usually includes joint problems in its ragbag of symptoms.

I recently had a nasty flare-up of the condition as a result of a reaction to a powerful probiotic prescribed by my doctor, and was shocked by some of the symptoms I got. As well as severe joint, muscle and tendon pains, I suffered extreme fatigue - the worst I've ever experienced during a flare-up. At the height of this, I started getting weird mental symptoms too. Depersonalisation - the feeling I was someone else or was watching my own actions - and feelings of unreality. Or maybe even a kind of hyper-reality that's hard to describe. Seeming to see everything in heightened colour and detail - e.g. looking at a tree and seeing all the veins on all the leaves. Sounds great but it was a scary experience. Other days I seemed to lose touch with reality altogether. One day I got lost coming home from the office, ended up sitting on a park bench crying because I couldn't remember how to get home!

After a week or so of this it dawned on me it might be a reaction to the probiotic. I stopped it and quickly recovered.

Regardless of whether or not you're taking Plaquenil I really think you should see your GP and get some blood tests. If you are on Plaquenil, consider stopping it.

Why don't you try starting a new thread headed something like "Side-effects of hydroxychloroquine?" in one or more of the forums where people are likely to be taking it? Quite a lot of chat about it on the Sjogren's board, but I'm sure you'd also find references to it under arthritis, lupus, possibly scleroderma and auto-immune.

But you should still see your GP if you haven't recently. As already mentioned, flare-ups of auto-immune conditions can in themselves occasionally cause strange mental symptoms.

Merlin, my original suggestion still stands. Get yourself checked out by your GP if you haven't already. I mean blood tests and a basic neuro examination, as some of your symptoms might just be down to a neurological problem. But remember you're not obliged to actually take everything that's prescribed! Fortunately, the law requires pharmacists to leave the notices in packs of medication these days. (Unbelievably, when I was a young woman, these were actually removed so as not to "worry" the patient!) Read the notice before starting, google the med thoroughly and, if you decide to go ahead with it, start on the smallest possible dose.

When you get to see the psychiatrist, tell him your medical history and also mention you were taking hydroxychloroquine.

I'm not saying this is necessarily fraud on the part of the drug companies, though I suspect there is sometimes a rush to get to market before the competition. It's mainly that the first 10 or 20 years on the market inevitably act as a sort of extended trial of any drug, once millions of people start taking it.

That's why, when starting a drug that's new to you, it's a good idea to seek out a population of people who've already taken it, via forums like this one, for example. Within the bounds of common sense, of course - obviously if you had a severe infection you'd start taking the prescribed antibiotic immediately. I'm referring mainly to pain-killers, anti-inflammatories and psycho-active drugs prescribed for minor psychiatric conditions like anxiety - often, in the latter case, by GPs who know very little about their side- and withdrawal effects. Oh and statins too... but don't get me started on that one!

Betsy, you might be wondering why I broke my own rule when rushing headlong onto a full dose of the probiotic I took recently. And that would be a good question! I'm normally very cautious, beginning with a tiny dose even when starting on a new OTC supplement. I think I was lulled into a false sense of security by the fact that my current GP, who I trust implicitly and who openly expresses his distrust of Big Pharma at every available opportunity, recommended it so warmly. That lesson has now been learned!