neurasthenia (nyŏrˌəsthēˈnēa) [key], condition characterized by general lassitude, irritability, lack of concentration, worry, and hypochondria. The term was introduced into psychiatry in 1869 by G. M. Beard, an American neurologist. Used by Freud to describe a fundamental disorder in mental functioning, the term was incorrectly applied to almost any psychoneurosis and has been largely abandoned.
More on neurasthenia from Fact Monster:
See more Encyclopedia articles on: Psychology and Psychiatry