Measuring interpersonal problems in people with mental retardation.

Despite interpersonal problems being commonplace in the clinical presentations of people with mental retardation, previous efforts to index interpersonal difficulties have tended to unsatisfactorily rely on external ratings. The Inventory of Interpersonal Problems-32 is a psychometrically robust self-report measure of interpersonal problems in adult populations. We found that this instrument retained many of its psychometric properties when used with a sample of 255 respondents with mild mental retardation. Results indicate four usable subscales alongside the full-scale when employed with this population. The subscales produced generally satisfactory internal and test-retest reliabilities and sound concurrent and internal-external criterion-related validities. Results are discussed with reference to further development of the measure in relation to people with mental retardation.