Psychomotor agitation: poorly defined and badly measured

Background: Psychomotor agitation is commonly associated with various psychiatric disorders. This article reviews the definition and measurement of agitation over the past 100 years. Methods: Definitions and descriptions of agitation were taken from dictionaries of etymology, medicine and psychiatry, and from psychiatric textbooks. A systematic MEDLINE (1965-1996) search of 'psychomotor', 'agitation', and 'restlessness' was conducted. This was augmented by a search for other relevant references cited in the articles identified by MEDLINE. Results: The definition of psychomotor agitation has varied in ambiguous and contradictory ways, both over time and in contemporary writings. Tools developed to measure agitation are either too unreliable, or else reflect this conflict of definition and are not comparable. Conclusions: A preferred definition of agitation is proposed which takes into account both theoretical and empirical data. This has implications for further research into psychomotor agitation in classification of and treatment response in affective disorders, old age psychiatry and the evaluation of putative anti-agitation drugs. (C) 1999 Elsevier Science B.V. All rights reserved.