By TERRY SEJNOWSKI
Is there anything good about insomnia? Could there possibly be any upside to a long, torturous sleepless night?
To answer the question, let’s look at another condition entirely.
Postpartum depression affects between 5 percent and 25 percent of new mothers. Symptoms — including sadness, fatigue, appetite changes, crying, anxiety and irritability — usually occur in the first few months after child birth. There is a simple way to alleviate postpartum depression in just a few hours: sleep deprivation.
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. 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. Sleep deprivation used as a treatment for depression is efficacious and robust: it works quickly, is relatively easy to administer, inexpensive, relatively safe and it also alleviates other types of clinical depression. Sleep deprivation can elevate your mood even if you are not depressed, and can induce euphoria. This throws a new light on insomnia.
This remarkable result is not well known outside a small circle of sleep researchers for three good reasons. First, sleep deprivation is not as convenient as taking a pill. Second, prolonged sleep deprivation is not exactly a desirable state; it leads to cognitive defects, such as reduced working memory and impaired decision making. Finally, depression recurs after the mother, inevitably, succumbs to sleep, even for a short nap. Nonetheless this is an incredibly important observation; it shows that depression can be rapidly reversed and suggests that something is happening in the sleeping brain to bring on episodes of depression. All this offers hope that studying sleep deprivation may lead to new, unique and rapid treatments for depression.
Scans suggest that something happening in the sleeping brain can bring on episodes of depression.
Neuroscientists have been trying to solve this puzzle. The first hint of what may be happening during sleep came from J. Christian Gillin, a former colleague of mine at the University of California at San Diego and the San Diego Veterans Affairs Medical Center. Using imaging, he found that a small area of the cerebral cortex in the front of the brain — the anterior cingulate cortex — which was consistently overactive in depressed patients, quieted to normal levels of activity after the patients were deprived of sleep. And when the patients were allowed to sleep, the activity in this area returned to the elevated levels.