Well, medically they tend to start with a sleep study to pinpoint when in the cycle it happens.

It's sounding a ot like the umbrella answer, but melatonin miiiight help. It would have to be extended release, though. The idea is taking something that would keep pushing your brain into sleep mode so that you have a deeper sleep cycle.

Talk to your doctor, of course - especially since you'd need the sleep study if the melatonin or OTC sleep aids don't work.