This question is going to get mixed responses from the public. There are going to be the group of skeptics who don't believe in astral projection for a start so the answer to the above question from them is undoubtedly a firm no. As far as these skeptics are concerned there is going to be a scientific explanation for the experience. Then there will be those who have experienced astral projections and sleep paralysis and who may either believe there is a connection from what they have experienced or will be open-minded to the possibility that there could be a connection. I mean let's face it. If you have experienced astral projections you may as well be open-minded to just about any possibility since astral projections are out of this world-quite literally and for the majority who have had astral projections do believe to some certain extent that their experience was real.
I have experienced both astral projections and sleep paralysis so I feel I may be in some position to speak on the subject. I first began to experience sleep paralysis in my teens. I use to have an experience a few times a week. For most people who have experienced this you will agree with me when I say it can be a terrifying experience certainly at first anyway. You come into awareness during your sleep yet your physical body is still asleep but your mind is awake and alert. Because your physical body is still asleep it is paralyzed. This is something that occurs naturally during your sleep to stop you from acting out your dreams and injuring yourself. You can't move, you can't scream and you can't do anything but lie there wondering what the hell is going on. If you are really unlucky you may perceive that there is a menacing entity of some sort in the room coming towards you or even worst sitting on your chest squashing the air out of your lungs. This entity is never perceived as being nice by those who experience it and it can appear in many different disguises and you may actually get to see it if you get the hallucination side of this paralysis. This is where you can actually see things in the room with you during the paralysis and 9 out of 10 times what you see is not going to be pleasant. It is like experiencing the realest of real nightmares you will ever have. You feel helpless and vulnerable and scared out of your mind and your awake yet you can't move and you get the feeling that someone or something really bad is in your room with only one agenda and that is to hurt you. This entity usually wants to harm you rather than be nice and most people experience through sight or perception that they are being strangled and suffocated by the entity. You may feel like you can't breathe and you try to scream for help but no sounds come out of your mouth. Eventually your physical body wakes up usually within seconds to minutes and the experience is over leaving a sour taste in the victim's mind. A lot of people have suggested that the entity perceived is a spirit or demon who does want to hurt you and by the way they behave it wants to kill you. I have to say I am a less of a believer on it being a spirit or demon wanting to hurt people. I mean, they don't seem to be very successful do they if you think about it so what is the point? People don't die from sleep paralysis so if it is a demon or spirit wanting to hurt you it really isn't getting very far. Anyway as I say I just find it hard to believe it can be a spirit or demon. I think during an experience like sleep paralysis you experience fear and quite naturally and it may manifest as being a demon or entity though a perception, hallucination or dream image. Some people will be convinced it was a spirit because they saw it but during many of many experiences I saw a dark cloaked entity who would come up to me then put his arms around my throat and proceed to strangle the life out of me-or try to at least. I have met this chap many a times and I am still here and I believe this is the product of my own mind created by the fear of the experience. I do feel that in those altered states of consciousness we can be visited by entities I just feel that they are not going to try and harm you to that extent but that is just my opinion. Too many people experience the same thing and I just think it is more fear based.
Anyway I have had sleep paralysis where I have experienced the hallucinations that being the dark cloaked entity and without the hallucinations. During some of my last lot of sleep paralysis experiences I noticed something and that was waves of energy going through my body. Sometimes I could feel rushes of gale force winds blowing loudly around my body and on one occasion I could feel my top being moved by these strong winds. Sometimes I may hear a loud noise in my ears or head like a train is speeding past right next to my head. Now these are all signs an astral projection is about to occur. I have experienced these signs just before I have astral projected and I have experienced them during sleep paralysis and there has been times when I have astral projected from the sleep paralysis state. I came across an article once and the author suggested that around the time a sleep paralysis occurs we (astral consciousness) is either leaving or returning to our physical body from astral projection state. Sometimes we come aware and our brain panics during the moment of leaving or re-entering or when an astral projection is about to happen and our mind wakes. There is different levels of consciousness that we reach for different states. For example you are in waking consciousness now if you are reading this. There is the state of consciousness that we experience between sleep and awake and there is dreaming consciousness and astral projection consciousness and many more. In sleep paralysis it maybe that we were leaving or entering for astral projection but woke up but into waking consciousness which in theory is the ideal state of consciousness to be in for a good astral projection experience to happen however for some who don't know what is happening to them because they feel quite awake and alert like they would if fully awake during their day they will became frightened and scared because they can't move and this fear as I said may cause the perception that something is in the room. The brain panics and feels vulnerable and goes in on survival instinct and assumes that what is happening to the physical body is negative and reacts as if it is so. Our consciousness is separate from our brain. Although astral projection is a natural thing to occur during our sleep when such a thing occurs and we suddenly wake up during the process the brain will freak out naturally as you will too if you are not use to it. It is like the brain is thinking the physically body is dying because our consciousness has either left, come back or preparing to leave its physical body and the brain goes into meltdown which may affect the breathing and which then goes onto give the delusion that a being is trying to strangle you to explain the breathing difficulties that feels like is happening.
The scientific explanation is that we or our minds wake up too soon before the physical body has had a chance to wake up. Really mind and physically body should wake around the same time so as soon as you open your eyes you can get straight out of your bed. This could be due to the chemicals in the brain at that given time malfunctioning if you like.
I think both theories could be possible, maybe it could be a mixture of both the scientific and the spiritual or just one or the other but one thing is for sure sleep paralysis can lead to astral projection. It is the perfect state to be in to induce an astral projection so the next time you experience sleep paralysis try to put the fear to the back of your mind and see it as a great opportunity to have a astral projection. Also if you do become aware during a sleep paralysis staying calm is the key if you want the experience to end quicker. The more you fight it the worst it will be.