insomnia
"I always fall asleep reasonably quickly but wake briefly at the end of each sleep cycle (which get shorter as the night progresses) until about 2am when I remain awake for about 2 to 3 hours. With Belsomra I still wake at the end of each cycle but quickly fall asleep again throughout the whole night.
It took some trial and error to get the right dose. A 20mg tablet worked but left me sleepy the next day. 10mg (half a tablet) works well for a whole night without next day sleepiness and 5mg was ineffective."