Science Fact: Sleep deprivation is generally thought to be a bad thing, but it can actually make you happier! This surprising fact has been known for years by physicians who treat Major Depressive Disorder, commonly known as clinical depression.
In the last few years, people who study depression have been using functional magnetic resonance imaging (fMRI), an imaging technique that measures blood flow as an indicator of brain activity. A number of clues are coming together than may permit more effective treatment of depression without using drugs, or using much smaller doses of drugs. And the research results also suggest how we can add to, or subtract from, our own happiness – although why anyone would want to be less happy is a mystery!
Modern attempts to understand the brain treat it as a series of networks, each performing a certain function and located in specific areas of the brain. Three networks whose interactions are important in depression are:
– cognitive control (making conscious decisions)
– default mode (“wakeful rest”) and
– affective (feelings and emotions)
These three networks connect through an area called the dorsal nexus, a small part of the brain located on both sides of the head above the ears. Researchers at Washington University found that the linkage through the dorsal nexus was unusually strong in patients with clinical depression, as if the depression is facilitated or even caused by “too much connectivity” in the brain.
It is known that sleep deprivation temporarily helps those who have clinical depression, although the reasons for this effect are unclear. Therefore, a group of researchers at the University of Rochester and New York University recently studied the effect of sleep deprivation on a group of non-depressed volunteers. fMRI showed that lack of sleep changed the brain activity routed through the dorsal nexus, strengthening some connections and weakening others. In particular the cognitive network, in which we exercise conscious control, was strengthened and the affective network, in which we are at the mercy of our emotions, was weakened. This shift from emotional dominance to rational dominance may explain why depression was decreased and “put in its place” by sleep deprivation.
These studies point to a possible mechanism by which sleep deprivation helps depressed patients. They also emphasize that you can significantly shift the flow of neural activity by voluntary changes in your day-to-day activities.
Science Speculation: What are the practical implications of this work?
First, for those who suffer from clinical depression: Not just sleep deprivation but more generally, manipulating the sleep-wake cycle, is a powerful treatment for depression. 60% of patients experience “profound and rapid” improvement. When sleep cycle adjustment is used alone, the effect wears off in a day or two; however, when it is combined with other therapies, it can provide longer-term relief. The other therapies may involve drugs (although at a lower dose than when used alone), or non-drug treatments such as bright lights or regularly shifting the sleep-wake cycle (“phase advance procedures”). Other supplementary treatments such as music therapy could have a similar synergistic effect. Thus a patient suffering depression may not have to commit himself to a life of psychoactive drugs: life-style changes have a measurable, substantial affect on the functioning of the brain, and may partially or totally replace drug-only therapies.
For those who are not clinically depressed but who sometimes experience feelings of sadness or emptiness, this research adds to our understanding of how our minds work. A temporarily sad person may experience some relief by adjusting his sleep cycle. I’m not suggesting self-diagnosis and self-treatment of an illness; rather, I’m saying that if you’re healthy, pay attention to the way your mood is affected by the time you go to bed and the time you wake up. You might learn ways to adjust your schedule to improve your overall happiness.
However, the brain is a mysterious organ: one study of sleep deprivation in healthy individuals suggests that sleep deprivation will make you happier if you are an “evening person” (“evening chronotype”), but may make you less happy if you are a “morning person”. So there is no “magic bullet” – each person needs to decide what personal habits best work for them.
Does occasional sleep deprivation make you happier or less happy? Does this seem to correlate with whether you’re a night owl?
Drawing Credit: uroesch, on openclipart.org