Determining the capability of individuals with mental retardation to give informed consent.

Interviews were conducted for individuals without mental retardation and with mild or moderate mental retardation in order to determine their capability to provide informed consent to hypothetical treatment vignettes. Protocols were developed to permit structured interviews, and standardized scoring procedures were devised to provide reliable determinations. Use of these procedures resulted in highly reliable ratings across different clinicians, and the likelihood of being determined capable to provide consent was positively related to level of intellectual functioning. Results point to the need to educate individuals with mental retardation about treatment situations and to balance protection from harm with self-determination.