Not saying this applies to anyone here-
To add one more possible cause of disturbed/interrupted sleep- too much alcohol can easily do that. Though one glass of something actually helps some folks get to sleep and sleep well, too much can really mess up your ability to get restful deep REM sleep. It causes restlessness, weird and unpleasant dreams, waking up multiple times during the night and not being able to get back to sleep. Needless to say, those who drink too much regularly often feel strongly that their sleep problem is due to something else.