I've heard patients who complain of "brain fog" (and fatigue) claim a reduction in "brain fog" (and more mental clarity) when they get fewer hours of sleep (usually less than 5.5 hours).
Here I'd define brain fog as a lack of mental clarity, slow and muddled thinking, trouble stringing thoughts, drowsiness, a reduced ability to focus, a feeling of drifting off, and a reduced ability to shift attention. Delirium (without hallucination) could be a close medical term.
My questions are:
Any theories on why this may happen?
Is anyone familiar with any research regarding less brain fog with less sleep?
I've read in a paper by MacLean and Datta (2007) that sleep deprivation has been successfully used to treat depression, but not so with anxiety.
Indeed, in clinical studies, sleep deprivation has been an effective form of treatment for major depressive disorders in humans (Clark et al., 2001; Giedke et al., 2003; Gillin et al., 2001); but deprivation has shown little or negative results in patients diagnosed with anxiety disorders (Dinges et al., 1997; Labbate et al., 1998). Results from recent REM and total sleep deprivation studies in rodents demonstrate the anxiogenic effect of disrupted sleep (Silva et al., 2004; Suchecki et al., 2002a; Suchecki et al., 2002b).
Depression and delirium are two distinct things, and I'd be interested in hearing more about how sleep deprivation effects delirium -- since it seems that brain fog is not a widely used term.
Robert Ross MacLean and Subimal Datta (2007). The relationship between anxiety and sleep-wake behavior after stressor exposure in the rat. Brain Res. 2007 August 20; 1164: 72–80. Published online 2007 June 27. doi: 10.1016/j.brainres.2007.06.034
I'm going to update this as I learn more (until I get a reasonable answer), in attempt to both log and share what I'm learning on the subject.
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.
SEJNOWSKI, T. (2010, April 7). In Sleepless Nights, a Hope for Treating Depression - NYTimes.com. Opinion - Opinionator - NYTimes.com.
A study in rats suggests that individual neurons take a nap when the brain is forced to stay awake, and that the basic unit of sleep is the electrical activity of single cortical neurons.
Colwell, C. S. (2011). Neuroscience: Sleepy neurons? Nature. Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved. Retrieved from http://www.nature.com/nature/journal/v472/n7344/full/472427a.html