Actually, it is purely biochemical and hormonal in nature. I have had PMS for years. But lately it has been fairly well controlled by antidepressants, and then splatted into non-existence by mood stabilisers. Now, I am reducing my dose of one antidepressant to see what happens. Funnily enough, when you come off an antidepressant, you might feel depressed during that time of the month when you've always been unstable. It's not surprising.
However, the nightmares and subsequent severe anxiety attacks are not helping my ability to get out of bed. The apathy and indecisiveness are not helping my getting anything useful done with the day. And the attacks of random tearfulness and existentialism are not helping my recovery. When you are sad and wobbly with no external trigger, your brain manufactures lots of possible Reasons why you feel that bad. And then you have to go round attacking them with Logical Thinking along the lines of "No, that is not true. These feelings are not real. It is just bad brain chemistry.". This is quite tiring, especially if you are already tired from not getting enough sleep due to the nightmares.
Also, I am stuck at a level of 150 mg a day of Efexor, because if I'm unable to keep up appearances at this dose then I certainly can't go lower. Even though I want to come off the stuff as soon as possible so we can see how able to cope I really am, and whether I need more of the mood stabiliser.
The really strange thing is that I feel awful - horrible, and wretched - and really not able to cope or think or function. Yet according to Richard, who has been observing me for more than a decade, even at my most irrational lately it has been nothing compared to what I used to be like, pre-meds and therapy. That's... quite a scary thought. How on earth did he ever put up with me?