The natural history of psychiatric syndromes associated with Huntington's disease (HD) remains unclear, and longitudinal studies of symptoms such as depression, apathy, and irritability are required to better understand the progression and role of these syndromes and their effect on disability. Self-administered scales such as the Beck Depression Inventory (BDI) may be useful to document changes in symptoms over time, but the validity of self-report may be questionable with the inevitable progression of cognitive deficits. An alternative to the patient's self-report would be assessments by the caregiver. The authors assessed interrater agreement between patient self-assessment and caregiver assessment of patients status for the presence of depressed mood using the BDI and apathy and irritability using an apathy and irritability scale. Agreement between these scales across strata of cognitive status was also examined. Interrater agreement varied from moderate to good for the BDI, depending on patient cognitive status. Agreement for the apathy scores was low for patients with poor cognition and fair in patients with better cognition. Irritability scale agreement was fair at best and was the worst in patients with the most intact cognition. Caregiver assessment of patients' moods and apathy may be an acceptable alternative to patient self-report as patients' cognitive status worsens.