One of the main causes and reasons for sleep paralysis is that the brain is not moving smoothly between the stages of sleep. Very rarely is the sleep paralysis linked to any psychiatric problems.

yes, but as i see your only awake in your nightmare...that also causes sleep paralysis ..

Sleep paralysis can come while sleep deprived or during periods of high stress. You may not experience sleep paralysis anymore because you are getting more needed sleep or no longer in a period of high stress. Sleep paralysis is the inability to move your body when falling asleep or while waking up. The sensation can be very scary. While 1/3rd of ALL people have experienced sleep paralysis at one time or another in their life, it usually goes away. Individuals who experience sleep paralysis consistently and frequently may have a sleep disorder called narcolepsy.

Yes, you can induce sleep paralysis by relaxing. Here's how to: http://www.youtube.com/watch?v=Tb8eGsu_nX4

Sleep-Paralysis - 2004 was released on:

Australia: 1 May 2004

USA: 28 March 2006