Posttraumatic Stress Disorder and DementiaPosttraumatic Stress Disorder and Dementia

In 1984, Churchland¹ contended that the Cartesian mind-body dualism is refuted by the observation that damage to specific parts of the physical brain produces observable changes in specific mental processes. There can now be no doubt about this fact among behavioral scientists. However, the converse proposition (ie, that mental processes can produce brain damage) is less clear. There is no question that psychological events can change the brain. Neural plasticity is now understood to be the structural basis of learning. Stressful experiences mediated by release of glucocorticoid stress hormones have been shown to produce atrophy of the hippocampus in animals.² However, the atrophic effect is not ubiquitous because stress and glucocorticoids also lead to hypertrophy of another brain area, the amygdala.³ It could be spurious to refer to a brain that has atrophied in some areas but hypertrophied in other areas (presumably as an adaptive response) as damaged.