Agreed as well. Nothing makes the day WORSE than not enough sleep; and it never feels like enough.

Edit: And, as is the style of the day, we've had links on HN/SA and others that not enough sleep hampers cognition, weight control, and stress (which are all triggers/symptoms for depression in many people). So, you need to sleep more, and less, simultaneously?

Similarly, I find my depression is fueled by lack of sleep and a strong sleep regimen(sleeping in bouts rather than settling down for 4-6 hours before getting up to go to the bathroom, etc).

Depression is a collection of symptoms—he could very well be depressed with a different underlying cause.

A rule of thumb is "can't go to sleep in evening == anxiety; wake up too early == depression". It's a very rough rule. Once disrupted sleep patterns kick in it can be hard to get them back to normal and they go all over the place.

Depression comes in a few different forms, and often people learn to live with it for so long before seeking treatment that they have different lists of symptoms.