Tangentiality - Wandering from the topic and never returning to it or providing the information requested.

Specific thought disorders include derailment, poverty of speech, tangentiality, illogicality, perseveration, neologism, and thought blocking.

Ferry, S.C.; Weinberger, S.: Curvature, tangentiality, and controlled topology.

Disorganised thinking includes tangentiality, circumstantiality and a proneness to loose associations between elements of thought which results in speech that often makes limited sense with multiple apparent irrelevancies.

According to the St. Louis system for the diagnosis of schizophrenia, tangentiality is significantly associated with a low IQ prior to diagnosis (AU Parnas et al 2007).

Tangentiality as a medical symptom is a physical symptom observed in speech that tends to occur in situations where a person is experiencing high anxiety, as a manifestation of the psychosis known as schizophrenia, in dementia or in states of delirium.