Which of the following is NOT one of the broad categories used to classify syncope according to underlying etiology?

In the classification of syncope, the primary categories typically used to categorize the underlying etiology include reflex or neural-mediated causes, orthostatic hypotension, and cardiogenic causes. Reflex or neural-mediated syncope occurs due to a transient malfunction in the autonomic nervous system, leading to vasodilation and bradycardia. Orthostatic hypotension results from a failure to adequately regulate blood pressure when changing posture, often leading to a drop in blood flow to the brain. Cardiogenic syncope is related to heart conditions that impair blood flow, such as arrhythmias or structural heart disease.

Psychogenic causes of syncope are not classified as broad categories of underlying etiology in the traditional framework. While psychogenic causes can lead to episodes that may resemble syncope, such as non-epileptic seizures or fits due to panic attacks, these are generally considered outside the best-established medical categories used for classifying syncope. Therefore, psychogenic mechanisms do not belong in the same classification scheme as the primary medical causes, making it the correct choice as the option that does not fit.