Assessing Mental Health Difficulties of Persons With Huntington's Disease: Does Informant Presence Make a Difference?

METHODS:Data for four subsamples from ENROLL-HD were examined: manifest for HD (N=4,109), premanifest (N=1,790), genotype negative (N=1,041), and family members with no genetic risk (N=974). Assessment interviews with and without an informant present were identified, and the subsamples were compared on three subscales of the short-form Problem Behaviors Assessment: affect, apathy, and irritability. Differences in scores between participant-only and informant-present interviews were examined via multiple regression, controlling for demographic, disease-related, and individual confounds.

RESULTS:Significant differences in apathy and irritability scores were found between participant-only and informant-present conditions for the premanifest, manifest, and genotype-negative subsamples. Affect subscale scores were not influenced by informant presence. When the analysis controlled for confounds, informant presence significantly increased irritability scores in the manifest, and genotype-negative groups and significantly increased apathy scores in the manifest group. CONCLUSIONS:Apathy may have been systemically underreported in participant-only interviews, which supports previous findings that persons with HD underreport mental health symptoms. When an informant was present, irritability scores were higher for both HD and non-HD individuals, suggesting that underreporting via self-report may be attributable to non-HD factors. Informant contributions to apathy assessments may be particularly important for persons with HD. Clinicians should note potential underreporting regarding irritability and affect, which was not remediated by informant presence.