I haved marijuana since I was 17, I am now 29. Being schizophrenic (targetted) the professional opinion is that pot will cause the illness or cause it to be worse, also, it will effect with their 'treatment' (mind control, soul control, spiritual destruction).
When I use marijuana, my consciousness becomes excited, and often, I will go for a walk or throw some punches, exercise, or some such. Most often, I go on long winded tirades here on the internet. It accelerates my mind and I can stay up for two or three days in a row with sufficient product on hand. When I first started using pot, it was with other people and this was a downside to the pot experience. Stereotypes and irrational behavior were the result of social use of pot, also, brainwashing by certain biker types.
Marijuana puts you in a receptive state of mind, if you are with other people. If you are by yourself, creative ideas and radical information will compile themselves out of your raw memory. Since my whole adult life has been hindered by neuroleptic treatment, my experience with marijuana has been diminished and it requires significantly more of the drug to activate the effects, precisely due to the fact the neuroleptic stops dopamine in the brain.
I just know that when I first started and was by myself while using, I isolated myself in the outhouse and had many satanic fantasies. In your case, that is likely not what is happening, just due to the conditions of your life. Yet, the knowledge which I now possess is influenced by the radical experience of marijuana.
However!!! Whether or not marijuana demolishes astral abilities I can not say, certainly, the vile and sickening neuroleptic certainly does have many negative effects. I just know that marijuana enhances imagination, and is a useful aid to constructive thought ( though those thoughts will have to be reevaluated and reorganized later on in sobriety). It is a useful, relaxing, and enjoyable drug. I find that it helps me focus, and I get what I want from the experience. I will hold the opinion that marijuana is not the drug to use to achieve astral experiences, because you focus more on 'feeling high' than 'becoming astral/spiritual'.