Affiliations: [a] Neurology Department, Vanderbilt University Medical Center, Nashville, TN, USA
| [b] Psychiatry Department, Vanderbilt Psychiatric Hospital, Nashville, TN, USA
Correspondence to: David Isaacs, MD, MPH, 1161 21 Ave S, A-0118 MCN, Nashville, TN 37232, USA. Tel.: +1 615 936 2025; E-mail: [email protected].
Note:  These authors contributed equally to this work.
Abstract: Background:Psychiatric symptoms are widely prevalent in Huntington’s disease (HD) and exert greater impact on quality of life than motor manifestations. Despite this, psychiatric symptoms are frequently underrecognized and undertreated. Lack of awareness, or anosognosia, has been observed at all stages of HD and may contribute to diminished patient self-reporting of psychiatric symptoms. Objective:We sought to evaluate the impact of anosognosia on performance of commonly used clinical rating scales for psychiatric manifestations of HD. Methods:We recruited 50 HD patients to undergo a formal psychiatrist evaluation, the Problem Behavior Assessment-Short Form (PBA-s), and validated self-report rating scales for depression, anxiety, and anger. Motor impairment, cognitive function, and total functional capacity were assessed as part of clinical exam. Patient awareness of motor, cognitive, emotional, and functional capacities was quantified using the Anosognosia Rating Scale. Convergent validity, discriminant validity, classification accuracy, and anosognosia effect was determined for each psychiatric symptom rating scale. Results:Anosognosia was identified in one-third of patients, and these patients underrated the severity of depression and anxiety when completing self-report instruments. Anosognosia did not clearly influence self-reported anger, but this result may have been confounded by the sub-optimal discriminant validity of anger rating scales. Conclusion:Anosognosia undermines reliability of self-reported depression and anxiety in HD. Self-report rating scales for depression and anxiety may have a role in screening, but results must be corroborated by provider and caregiver input when anosognosia is present. HD clinical trials utilizing patient-reported outcomes as study endpoints should routinely evaluate participants for anosognosia.