Meaning and purpose in Huntington’s disease: a longitudinal study of its impact on quality of life

Objective: Previous work in Huntington’s disease (HD) has shown that a sense of meaning and purpose (M&P) is positively associated with positive affect and well-being (PAW); however, it was unknown whether HD-validated patient-reported outcomes (PROs) influence this association and how M&P impacts PROs in the future. Our study was designed to examine if HD-validated PROs moderate the relationship between M&P and PAW and to evaluate if baseline M&P predicts 12- and 24-month changes in HD-validated PROs. Methods: This was a longitudinal, multicenter study to develop several PROs (e.g., specific for the physical, emotional, cognitive, and social domains) for people with HD (HDQLIFE). The sample consisted of 322 people with HD (n = 50 prodromal, n = 171 early-stage manifest, and n = 101 late-stage manifest HD). A single, multivariate linear mixed-effects model was performed with PAW as the outcome predicted by main effects for M&P and several moderators (i.e., an HD-validated PRO) and interactions between M&P and a given PRO. Linear-mixed models were also used to assess if baseline M&P predicted HD-validated PROs at 12 and 24 months. Results: Higher M&P was positively associated with higher PAW regardless of the magnitude of symptom burden, as represented by HD-validated PROs, and independent of disease stage. In our primary analysis, baseline M&P predicted increased PAW and decreased depression, anxiety, anger, emotional/behavioral disruptions, and cognitive decline at 12 and 24 months across all disease stages. Interpretation: These findings parallel those seen in the oncology population and have implications for adapting and developing psychotherapeutic and palliative HD interventions.