The human fear-circuitry and fear-induced fainting in healthy individuals--the paleolithic-threat hypothesis.

The Paleolithic-Threat hypothesis reviewed here posits that habitual efferent fainting can be traced back to fear-induced allelic polymorphisms that were selected into some genomes of anatomically, mitochondrially, and neurally modern humans (Homo sapiens sapiens) in the Mid-Paleolithic because of the survival advantage they conferred during periods of inescapable threat. We posit that during Mid-Paleolithic warfare an encounter with "a stranger holding a sharp object" was consistently associated with threat to life. A heritable hardwired or firm-wired (prepotentiated) predisposition to abruptly increase vagal tone and collapse flaccidly rather than freeze or attempt to flee or fight in response to an approaching sharp object, a minor injury, or the sight of blood, may have evolved as an alternative stress-induced fear-circuitry response.

Depression, anxiety and neuropsychological test scores of candidates for coronary artery bypass graft surgery.

The effect of depression and anxiety upon neuropsychological test scores of candidates for coronary artery bypass graft (CABG) surgery was examined. Sixty patients were administered the Beck Depression Inventory II and the State-Trait Anxiety Inventory, along with a battery of neuropsychological tests. Regression analyses were conducted in which the neuropsychological test scores were predicted using age, education, depression, anxiety, and combined depression-anxiety scores.