"Way back in  a German psychiatrist reported that sleep deprivation had a weird side effect It made some depressed people feel better. Scientists have been studying sleep deprivation and depression ever since.  A University of Pennsylvania research team has brought the data up to the present with a new metaanalysis  a study that pools data from other peoples studies  of the last  years of work on the topic. Related stories    Undiagnosed sleep apnea caused  NYC train crashes. Could you have sleep apnea too http  Their work confirmed that sleep deprivation  anything from three to four hours of sleep followed by  to  hours awake to no sleep for  straight hours  is indeed a powerful antidote to depression. In the  studies they analyzed  percent to  percent reported feeling less depressed. That sounds great but theres a huge problem  For more than  percent of patients the antidepressant effects are lost as soon as they get a good nights rest. Repeated exposure to sleep deprivation has had mixed results. The study the first metaanalysis of this topic in nearly  years was published this week in the Journal of Clinical Psychiatry. Philip Gehrman a Penn clinical psychologist who was senior author said the study proves that rapid treatment of depression is possible. But more research is needed to figure out why sleep deprivation works. His team is now conducting its own study. Hes not hoping to use sleep deprivation as a treatment but thinks that pinpointing what it does to the brain will help doctors develop other more sustained treatments.  Penn Medicine  Philip Gehrman is a clinical psychologist at the Penn Sleep Center.  Gehrman had hoped the metaanalysis would help figure out which depressed people are most likely to respond to sleep deprivation and whether the type of deprivation made a difference. It seemed like no matter how you sliced the pie the results were the same he said. Most of the studies did not have control groups so its hard to know how big the placebo effect was.  However Gehrman said the response to sleep deprivation is rapid and dramatic.  While there is a strong placebo effect in other types of depression treatments such as medication or talk therapy the response is usually much slower.  Gehrman is attracted to the topic because its so counterintuitive. This whole phenomenon is the complete opposite of what anyone would expect he said. Why would losing sleep be in any way helpful for depression People without depression feel worse when they dont get enough sleep.  Those with depression often suffer from sleep problems that make depression worse. Insomnia is the most common but some sleep too much. Treating their sleep problems often improves depression symptoms. Experts theorize that sleep deprivation may reset the circadian clock. But it is rarely used for treatment because it wears off so fast. I know of about three clinics worldwide that routinely use it Gehrman said. There are some studies showing that it can be helpful when combined with light or antidepressant medication treatment. Gehrmans team is now using brain imaging techniques to identify which brain circuits change in response to lack of sleep.  The hope is to then use neurostimulation such as transcranial magnetic stimulation to activate those circuits in a more fruitful way. Hes recruiting adults with moderate to severe depression who are willing to go  hours without sleep for science.  The study requires them to spend five days in a research lab. Theyll be paid  for participating."