Apparently, blogging may do the body good:

Self-medication may be the reason the blogosphere has taken off. Scientists (and writers) have long known about the therapeutic benefits of writing about personal experiences, thoughts and feelings. But besides serving as a stress-coping mechanism, expressive writing produces many physiological benefits. Research shows that it improves memory and sleep, boosts immune cell activity and reduces viral load in AIDS patients, and even speeds healing after surgery. A study in the February issue of the Oncologist reports that cancer patients who engaged in expressive writing just before treatment felt markedly better, mentally and physically, as compared with patients who did not.
Scientists now hope to explore the neurological underpinnings at play, especially considering the explosion of blogs. According to Alice Flaherty, a neuroscientist at Harvard University and Massachusetts General Hospital, the placebo theory of suffering is one window through which to view blogging. As social creatures, humans have a range of pain-related behaviors, such as complaining, which acts as a “placebo for getting satisfied,” Flaherty says. Blogging about stressful experiences might work similarly. …
The frontal and temporal lobes, which govern speech—no dedicated writing center is hardwired in the brain—may also figure in. For example, lesions in Wernicke’s area, located in the left temporal lobe, result in excessive speech and loss of language comprehension. People with Wernicke’s aphasia speak in gibberish and often write constantly. In light of these traits, Flaherty speculates that some activity in this area could foster the urge to blog.

Although I’d prefer gently to ignore the potential link between gibberish and the urge to blog, I can’t let slide the reference to sleep: When it comes to blogging, I suspect that any somnolent effects are negated (and then some) by the compulsion.