The "need" to dress does vary before and after orgasm. This is natural and due to the effect of neurotransmitters in your brain.
As you stimulate yourself your brain releases dopamine, serotonin, oxytocin and other feel good neurotransmitters. Dopamine levels peak with orgasm and then the prolactin kicks in. Prolactin is the neurotransmitters associated with the pulling away response post orgasm. For a short period after orgasm you no longer feel the dopamine influence. Then the prolactin wears away and you are back to your old cross-dressing self.
http://www.entelechyjournal.com/pull...after_sex1.htm
This all seems to suggest to me that crossdressing is a biological condition, and not just a psychological one. Your brain is interpreting cross-dressing as actual contact with a female, and responding by releasing appropriate neurotransmitters. Now most men can wear women's clothing and not get the same response. Their brains will not release the neurotransmitters, but ours do... I believe this indicates that sometime in our early brain development (synaptogenesis) we made neural connections between feminine articles and identity.
Please note: Getting aroused from dressing is not why we do the dressing. We do the dressing because we need to feel the good sensations from these neurotransmitters. Even if I never use crossdressing to arouse myself, I would still get sensations of comfort, well-being and self authentication from doing so.
