Abstract
This paper describes findings from a comprehensive review of instruments for assessing psychpathology and behaviour problems in people with mental retardation (Aman, 1991). The review was commissioned by the U.S. National Institute of Mental Health, and it encompassed a standard set of psychometric criteria to assess relevant instruments. Existing evaluation tools are characterized in terms of (a) types of raters used, (b) age groups encompased, (c) methods of development, (d) number of domains included, and (e) levels of mental retardation covered. An attempt is made to describe the structure of maladaptive behaviour by examining five instruments that were derived by factor analysis or were subsequently factor analyzed. The state of the field is examined with respect to the volume and diversity of recent work and by comparison with instruments developed for assessing normal IQ children. Several instruments are recommended for use with children and adults for purposes of screening, assessing broad behavioural dimensions, and detecting psychiatric disorders. Finally, a number of issues pertinent to instrument development are identified for future research and the need to study the very nature of psychopathology in this population is stressed.