catastrophic reaction [Gk, katastrophe, sudden downturn; L, re, again, agere, to act] , 1. the uncoordinated response to a drastic shock or a sudden threatening condition, as often occurs in the victims of car crashes and disasters. 2. an intense, spontaneous, aggressive, and confused outburst from a patient with severe dementia in response to something that is perceived as immensely frustrating. Violence is a potential.
