At last he heard of a doctor named Thomas Wehr, and went to him for help.

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

No other sort of pharmacy had worked for Charles B, who was desperate by the time he found Dr Wehr.

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

Dr Wehr, besides being a practising psychiatrist, is chief of the section on biological rhythms at America's National Institute of Mental Health.

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

Dr Wehr suspects that the effect may have to do with a surge, during the wee hours, of certain hormones associated with the thyroid.

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

Wandell and Wehr say their change-agent days are far from finished.

WSJ: Driving Change Without Rocking the Boat

"We have made a lot of progress, " Mr. Wehr says.

WSJ: Driving Change Without Rocking the Boat

As it happened, Dr Wehr's research had led him to explore the ways in which manipulating sleep can help some people ride the body's rhythms upward and out of depression.

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