It is widely accepted that assessment of child psychopathology requires data from multiple informants, such as mothers, fathers, teachers, and the children themselves.
However, assessment of adult psychopathology seldom employs data from people who know the adults who are being assessed. Would findings for adult psychopathology be different if they included reports by people who know the adults, in addition to self-reports? To shed light on this question, a University of Vermont team examined 51,000 articles from 52 journals to find correlations between self-reports and informants’ reports regarding adult psychopathology (Achenbach, Krukowski, Dumenci, & Ivanova, 2005).
Qualifying correlations were found in 108 (0.2%) of the articles. For parallel self-report and informant-report instruments, mean cross-informant correlations were .428 for internalizing problems, .438 for externalizing problems, and .681 for substance use. (Parallel instruments provided similar content for both kinds of raters.) For nonparallel self-report and informant-report instruments, the mean cross-informant correlation for psychopathology in general was .304.
These correlations indicate that different results may often be obtained from self-reports than from reports by people who know the adults who are being assessed. Assessment of adults, as well as children, may therefore be improved by systematically obtaining multi-informant reports, especially with parallel instruments.
Reference: Achenbach, T.M., Krukowski, R.A., Dumenci, L., & Ivanova, M.Y. (2005). Assessment of adult psychopathology: Meta-analyses and implications of cross-informant correlations. Psychological Bulletin, 131, 361-382.