Where wild minds come to rest
I'll try to resume what has been said in the long phonecall I had concerning treatment for MDD. A lot of things were said but maybe not in that order, anyhow, here's a resume.
The root of the cause, at least in my personal case (and I think it's right) would be a heightened sensitivity, probably processing physical sensations and the outer world differently. Also, in my case I am someone with a high baseline, existential anxiety, I don't feel at ease with the world. When children daydream or pretend-play it's a way to "practice" with all that input, but the mecanism becomes a defence strategy, some sort of layer of distance between the self and being in the world. When children become able to think logically and rationally that also becomes a favoured mecanism of creating distance, especially from emotions, as it allows to put a damper on everything by rationalising. They said it's often seen that DDers are actually refraining from feeling their own emotions, and prefer to feel "other people's" (=their avatars') or think about it.
I liked how they didn't put the daydreaming in a bad perspective. For them, the essence of human life is taking the things that happen to us and weaving them into significance, some story of our own, our personalities, except that daydreamer's have taken this capacity to a pinnacle, and they can integrate and create several environments, personalities, constantly experiencing the plasticity of what "experienced life" is itself.
Unfortunately, coupled with a continuous "overwhelm" from the world (because the senses are too strong or coping mecanisms are put in place badly), and some sort of baseline anxiety (can come from the childhood upbringing, situation you're in, or simply being wired in a high-strung way) the need can become compulsive. That compulsivity is rarely as full blown as in schizophrenia or OCD, because you realise you are still in a daydream and not in real life, but there is an element of need to it, a difficulty to break away and go back to daily life. I personally have some "gray areas" of compulsivity, checking doors and windows a lot, self-medicating with alcohol and sugar, with procrastination, being unable to sleep because I'm in a daydream, not feeling hunger when I DD, etc.
Now after all the theoretical framework in which this happens, there are some solutions.
They said another coping mecanism can be relearnt but that those are typically the hardest therapies and it's more or less one year of intensive, partially in-patient therapy. They said given that I still have some flexibility (different worlds and sometimes the capacity to break away from it) they don't think it's the best option.
Medication-wise, stimulants are dangerous because they increase the baseline anxiety, even if the overwhelm can feel lessened because you actually do things. They didn't put much credit into anti-depressants. Anti-anxiety medication might work, however, it is often pretty addictive. They would go down the road of a very low level of some atypical anti-psychotics to be able to control the compulsion to dream while not hindering the capacity and allowing for clearer thoughts. I wasn't really open to that, and I must admit I'm not a fan of medication in the first place.
They said the other options were to step outside of the over-intellectualisation which is another of my defense strategies, so no talk-therapy on its own, and turn to things like meditation and yoga. They said it would probably cause a lot of emotions to "get loosened" and that it was really important that I actually make the effort to work though those things, without judging them or trying to analyze them into some sort of grand life lesson.
Sorry for the long post. So basically, now, I'm on a one-month trial period of meditation at least 15 minutes 5 days a week (to be increased) and yoga 2x a week. If I can't seem to make it work they recommend medication, especially since, in my case, my capacity to work and be productive is on the brink of collapsing.