Developments in Brief : Lack of Sleep May Be a Dream Come True for the Depressed, Doctor Says

A bad night’s sleep is turning out to be good therapy for some patients with depression, according to Dr. David Sack of the National Institute of Mental Health.

Studies are leading to new information about depression and its relationship to the body’s natural rhythms--called circadian rhythms--which are intimately involved in sleep-wake cycles.

Researchers suspect that there are two separate biological clocks, or pacemakers: One controlling wakefulness and activity, and the other, hormone secretions and the part of sleep in which dreaming occurs. The pacemaker that controls wakefulness is thought to be out of kilter in depressed patients.

When depressed patients are deprived of sleep, the biological clocks are apparently aligned again and the symptoms of depression--loss of energy, diminished interest, impaired concentration, slowed motor activity and feelings of hopelessness, apathy and sadness--appear lifted.

In his laboratory, Sack deprives people of sleep at different times during the sleep cycle and then records physical, chemical and emotional changes. Although depressed patients are in a better mood the next day, other people are just plain tired. Sack says that for some reason a second night extended the positive effects by several days, weeks or, in some cases, months.