I think it will be proper to say that gambling dont makes us sleepy, if not we are already playing same game for hours And of course when we are winning we cant sleep, because greed forces us to win more and more, or ty to win back what was lost. Imho gambling give such emotions, that keep person awake for long time. I dont know what is secreted in our brain, but that makes us continue gambling non-stop, and we would stop only if our body feels really exhausted.