Also found in: Dictionary, Thesaurus, Medical.
Related to involutional psychosis: involutional melancholia
involutional psychosis[‚in·və′lü·shən·əl sī′kō·səs]
A prolonged psychotic reaction occurring in late middle life, characterized by depression and paranoid ideas. Also known as involutional melancholia.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.