Are you on any meds (not just psychiatric)? It could just be a parasomnia caused by your medicines. Maybe have a sleep study? I know the body can use intense dreams/images to get you to wake if you are having physical problems (say with breathing) and/or have taken a sleeping med and need to wake (to go to the bathroom or something :-)

Parasomnias: Nightmares, Night Terrors, Confusional Arousals and More