When numerous studies began to suggest that those suffering from the debilitating affects of postpartum depression were helped by sleep deprivation, many women were skeptical.
Postpartum depression affects between 5 and 25 percent of new mothers with symptoms that include sadness, fatigue, anxiety and irritability.
But now, nearly a decade later, new research that is grounded in those controversial sleep studies is providing new insight into the sleep-depression connection.
Sleep deprivation -- for all its ill effects, both physical and psychological -- can trigger a temporary mood shift, and now scientists say understanding how sleep and sleeplessness work might lead them to better treatments for depression.
A 2001 study of women with postpartum depression at the University of San Diego found that after losing just one night's sleep, new mothers' moods significantly improved.
Researchers reported that a sleepless night had antidepressant effects that were "efficacious and rapid." Sleep deprivation, they concluded, was also easy to administer, inexpensive and relatively safe.
"If a depressed mother stays up all night, or even the last half of the night, it is likely that by morning the depression will lift," said Terry Sejnowski, director of the Computational Neurobiology Laboratory at the Salk Institute for Biological Studies.
"Although this sounds too good to be true, it has been well documented in over 1,700 patients in more than 75 published papers during the last 40 years," he said.
"Neuroscience is just beginning to figure out the basic mechanisms of sleep," he said. "In our lifetime, we will have a much better handle on what exactly is going on and how to fix it. But right now, we are in the early stage of discovery and I can't promise a magic pill. But we have the tools to get the answers."
Postpartum depression experts say they have seen the phenomenon.
"A full night of sleep deprivation can snap someone out of depression, but a partial night isn?t very good," said Kathleen Kendall-Tackett, a health psychologist in the pediatric department at Texas Tech University School of Medicine. "And that is basically what new moms are getting."
She said most experts believe that postpartum depression is not physiologically any different from other forms of depression. It just has different stressors.
These sleep studies will "absolutely help women," according to Kendall-Tackett.
More than 20 million Americans suffer from mood disorders, about 9.5 percent of the population of 18 and older, according to the National Institute of Mental Health (NIMH). Major depressive disorders affect 14 million, and are the leading cause of disability for ages 15-to-44.
However, sleep deprivation only brings a temporary lift in mood, and mothers with postpartum depression often return to the blues even after a short nap. But that, suggests Sejnowski, means depression might one day be reversed just as rapidly.
No medical professional seriously believes that forced insomnia might be a long-term cure for depression, but the correlation between sleep and mood may one day yield answers.
"Unfortunately, we have a really primitive understanding of what happens when you go to sleep," Sejnowski said. "But we are beginning to do neurological studies in an area that has been really neglected."
The links between sleep and mood seem to contradict these theories and are still not well understood.