If you stimulate seizures in an animal every day, the seizures eventually become automatic; the animal will go on having them once a day even if you withdraw the stimulation. In much the same way, the brain that has gone into depression a few times will continue to return to depression over and over. This suggests that depression, even if it is occasioned by external tragedy, ultimately changes the structure, as well as the biochemistry, of the brain.
( Andrew Solomon )
[ The Noonday Demon ]
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