Objective: With Huntington disease (HD), a fatal neurodegenerative disease where the prevalence of suicidal thoughts and behavior (STB) remains elevated as compared to other neurological disorders, it is unknown whether STB and health-related quality of life (HRQoL) affect plans for the end of life or more broadly, advance care planning (ACP). Conversely, it is unknown whether ACP would provoke future changes to STB and HRQoL. Therefore, we sought to evaluate whether STB and HRQoL patient-reported outcomes (PROs) contribute to ACP and whether ACP relates to changes in STB and HRQoL at 24 months., Methods: HD-validated clinician- and patient-assessments (i.e., HRQoL PROs) were obtained at baseline enrollment, 12 and 24 months through our multi-center study (HDQLIFE™) throughout the United States among people with premanifest, early-stage, and late-stage manifest HD. We used linear mixed-effects models to determine the relationships between STB and HRQoL at baseline and HDQLIFE End of Life Planning at follow-up. Separate linear mixed-effects models were used to assess the relationship between HDQLIFE End of Life Planning at baseline, and HRQoL and STB at 12 and 24 months. False discovery rate adjustments were used to account for multiple comparisons., Results: At baseline enrollment, STB and HRQoL were not related to HDQLIFE End of Life Planning at 12 or 24 months. Similarly, at baseline, HDQLIFE End of Life Planning demonstrated no association with STB or HRQoL at 12 or 24 months., Interpretation: STB and HRQoL PROs do not significantly affect patient engagement with ACP. Most importantly, engaging in ACP does not cause untoward effects on HRQoL or STB for this rare neurodegenerative disease where the lifetime prevalence of STB approaches 30%., Competing Interests: L.L.S. receives financial support as a paid consultant from the HDSA, American Film Institute, University of Texas Houston (McGovern School), and Tikvah for Parkinson; he has received research support from the Memorial Sloan Kettering Meaning Centered Psychotherapy (MCP) National Cancer Institute (NCI) R25 Training, and Northwestern Physician Scientist Training program. J.P.T. owns stocks in Procter and Gamble and General Electric, and has received research funding through the University of Michigan with Complexa Inc., Retrophin Inc., and Goldfinch Bio, and the University of Michigan with Vertex Pharmaceuticals and Pfizer Inc. D.B. has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Speaker: Teva Pharmaceuticals, Acorda Therapeutics, Neurocrine Biosciences, Adamas Pharmaceuticals Consulting: Biogen Pharmaceuticals, Amgen Pharmaceuticals, Acadia Pharmaceuticals, Genentech, Inc., GE Healthcare, Gerson Lehrman Group, Guidepoint, L.E.K. C., and has received personal compensation in an editorial capacity for Editor: Annals of Clinical and Translational Neurology. B.M.K. received research grant support from the National Institute of Aging (NIA), National Institute of Nursing Research, and Patient-Centered Outcomes Research Institute; he has received speaker honoraria from the Parkinson's Foundation. H.G.P. receives funding from the NIH (CA197730; AG049666; MH121886; NR018693; CA218313). M.N. has received personal compensation in the range of $5,000–$9,999 for serving as a Consultant for Voyager. M.N. has received personal compensation in the range of $500–$4,999 for serving as a Consultant for Roche. M.N. has received personal compensation in the range of $5,000–$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche. M.N. has received personal compensation in the range of $500–$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Uniqure. An immediate family member of M.N. has received stock or an ownership interest from Fresca. The institution of M.N. has received research support from HDSA. The institution of M.N. has received research support from Parkinson Foundation. M.N. has received research support from Parkinson Foundation. The institution of M.N. has received research support from Neuraly. M.N. has received personal compensation in the range of $500–$4,999 for serving as a speaker with American Academy of Neurology (AAN). S.F. has received personal compensation in the range of $500–$4,999 for serving as a Consultant for Oscine Therapeutics. S.F. has received personal compensation in the range of $500–$4,999 for serving as a Consultant for uniQure. S.F. has received personal compensation in the range of $500–$4,999 for serving as a Consultant for MCG Health. The institution of S.F. has received research support from HDSA. The institution of S.F. has received research support from Michael J Fox Foundation. The institution of S.F. has received research support from Roche/Genentech. The institution of Dr. Frank has received research support from CHDI Foundation. The institution of S.F. has received research support from Huntington Study Group (HSG). The institution of S.F. has received research support from Triplet Therapeutics. J{has received research funding from the NIH (NS075321, NS103957, NS107281, NS092865, U10NS077384, NS097437, U54NS116025, U19 NS110456, AG050263, AG-64937, NS097799, NS075527, ES029524, NS109487, R61 AT010753 [NCATS, NINDS, NIA], RO1NS118146, R01AG065214), Department of Defense (W81XWH-217-1-0393), Michael J Fox Foundation, Barnes-Jewish Hospital Foundation (Elliot Stein Family Fund and Parkinson disease research fund), American Parkinson Disease Association (APDA) Advanced Research Center at Washington University, Greater St. Louis Chapter of the APDA, Paula and Rodger Riney Fund, Jo Oertli Fund, HDSA, Murphy Fund, and CHDI; has received honoraria from CHDI, Huntington Disease Study Group, Parkinson Study Group, Beth Israel Hospital (Harvard group), University of Pennsylvania, and Stanford University; is co-director for the Dystonia Coalition, which has received the majority of its support through the NIH (grants NS116025, NS065701 from the NINDS and TR 001456 from the Office of Rare Diseases Research at the NCATS); serves as Director of Medical and Scientific Advisory Committee of the Dystonia Medical Research Foundation, Chair of the Scientific Advisory Committee of the Parkinson Study Group, Chair of the Interim Executive Membership Committee of the HSG, Chair of the Nominating Committee of the HSG; Chair of the Standards Committee of the HSG, member of the Scientific Advisory Board of the APDA, Chair of the Scientific and Publication Committee for ENROLL-HD, and member of the Education Committee of the HSG; and has provided medical legal consultation to Wood, Cooper and Peterson, LLC, and Simmons and Simmons LLP. P.D. reports receiving funding from Vaccinex, Inc., Neurocrine Biosciences Inc., and UniQure, for his role as Site Investigator for clinical trials in Huntington Disease. D.C. reports consultant fees from AbbVie, Bristol Myers Squibb (BMS), Exelixis, Merck, Novartis, and Pfizer; reports licensing fees from FACIT.org; research grants (institutional) from AbbVie, Astellas, Aveo, BMS, GlaxoSmithKline, Merck, Novartis, and Pfizer; and is an officer of FACIT.org. N.E.C. reports research grants from the NIH, the Neilsen Foundation, and CHDI, as well as a contract from Teva Pharmaceuticals. She is also supported by research funding from the Alzheimer's Association, the Food and Drug Administration (FDA), as well as the Department of Health and Human Services—Centers for Medicare and Medicaid Services. She receives honoraria for her role on the CHDI scientific advisory board and is a consultant on the Traumatic Brain Injury (TBI) Congressionally mandated study., (© Leonard L. Sokol et al., 2023; Published by Mary Ann Liebert, Inc.)