A friend asked me if I thought Sleep Paralysis or the Night Hag experience was greater or worse for people doing the Great Work.
Starting with the basic cosmology, I believe the world as we know it is filled with spirits that we can't see. Angels, fallen angels, elementals, and all the spirits of the dead that stick around this side of heaven, you know the drill.
When we have strong emotions, we put off a certain kind of "energy" that can be sensed in a room or even a house. Some of the spirits we wade through every day can absorb nutrition from these strong emotions, the kind usually triggered by the amygdala.
In order for the hags to be ble to feed off someone, they've got to be going through some kind of emotional duress or stress that has their amygdala working over time. Whatever the clonazepam does in the brain seems to patch this leak up in most people.
The wandering hag spirit gets the scent of the leak and goes in for a free meal. Like a lamprey, the spirit attaches itself to the leak, and I believe it has something like the anesthetic saliva of a mosquito. this triggers that "I can't move" effect in the brain, and if we wake up during the attack, we can't do anything about it.
As a magician pursues the Work, they're patching up the holes, and learning new ways to deal with life that slowly eliminate the creation of any new leaks. So there's less to feed on. We aren't putting out a banquet every night for every wandering spirit.
However, in the early stages, and especially during a Tiphareth Initiation, there's usually a lot of pain involved. The "Gethsemane" experience, I like to call it. Crowley talks about the pain of a Tiphareth initiation in Liber XCV, "The Wake World."
"This Sixth House is called the Treasure House of Gold; it's a most mysterious place as ever you were in. First there's a tiny, tiny, tiny doorway, you must crawl through on your hands and knees; and even then I scraped ever such a lot of skin off my back; then you have to be nailed on a red board with four arms, with a great gold circle in the middle, and that hurts you dreadfully. Then they make you swear the most solemn things you ever heard of, how you would be faithful to the Fairy Prince, and live for nothing but to know him better and better. So the nails stopped hurting, because, of course, I saw that I was really being married, and this was part of it, and I was as glad as glad;"
So until you get to the married part, if you haven't done the Work in the previous spheres, you may have more hag experiences as the skin is scraped on your back.
Also, as you progress in the Work, you begin to interact with the spirits more, and you get a few that hang around you. They tend to scare away the more aggressive spirits, wake you up before anything can happen, or just beat the shit out of the hungry ghosts that dare to infiltrate your sphere. Depends on the familiars you attract and work with.