anxiety
"I was experiencing nightmares and terrors due to post traumatic stress disorder. They had me wired to the point of insomnia. I knew they weren't real, but the memory in the dream had been real so I was entirely overwhelmed every night with anxiety about going to sleep. I would take 50mg of trazodone every night and within 20 minutes no anxiety and within another 10 min I was dozing off. The only thing was I did have harder time waking in the morning mild hangover, but nothing a spot of coffee and shower did not remedy.  I get a full nights sleep now without waking in the middle of the night in a cold sweat or screaming."