He began with 40 depressed patients who had been successfully lifted from their depression by a night without sleep.

ECONOMIST: People, like all living things, are four dimensional

Noticing the circadian pattern of Charles B's depression, Dr Wehr asked him to get through a night without sleeping, and then to increase his nightly sleep only gradually, so that for almost a week he was awake during those crucial early-morning hours.

ECONOMIST: People, like all living things, are four dimensional

For starters, your doc may have you visit a sleep specialist to rule out sleep apnea, a common breathing disorder that wakes sufferers several times a night, sometimes without them even knowing it.

CNN: When to take a sleeping pill