Well, not the ADs themselves - I know they take about 8 hours to make me sleepy. More, now that I am getting decent rested sleep, is it possible that my body is desperately trying to catch up?
The last few nights, my normal bedtime of about 11ish has gone from 10.20pm, to 9.30pm to 9pm last night I am still wiped out today.
It isn't a lethargy type sleeping thing, it is a complete cannot stay upright thing.