I've always found the question about 'Inability to enjoy previously enjoyed activities' a difficult one, when filed under mood or in a psych evaluation.
I once documented to another M.E group about how the questionnaires I was ask to fill in could paint a misleading picture of patient health, and provide favourable statistics to those who set out with a psych agenda.
Several of the questions that hinted at not being able to do or enjoy certain things overlapped with the same sort of answer you might give based on physical health.
Obviously I'm not denying that there is a symptomatic depression that goes along with M.E (I would personally describe it as a perpetual bereavement), but my answer to such questions is much more measured than a yes/no response.
Take for instance, do I have the ability to enjoy playing a game of soccer? From a mental perspective, absolutely. If I was able to get up and run about and suffer no ill effects, well, I might actually faint from the relief and endorphins. Of course, if I answer that question in a positive way, it could be used to perceive some inaccuracy in my statements about my physical symptoms too.
It just seems like something that can be used against you from both sides. Some of the forms from the NHS date back to early 80s as well, it's not hugely inspiring stuff.
Anyway I digress, it is a good list, it's just that one question often bugs me.