I get about 5-6 hours of sleep Sunday night to Thursday night, and on Friday and Saturday it varies by a fairly large amount. The season plays a large role for me - the sun comes up at about 3-4am during the sumer in Edinburgh, and shines through into my flat. In the winter, it doesn't come up until around 9-10am, I think.

I generally go to bed between midnight and 2am.

I did once suffer from insomnia, around July last year. I had to go to the doctor to get some knockout pills, which helped a fair amount. It lasted roughly two weeks, maybe a bit longer.