F069 Apathy and verbal fluency in premanifest Huntington’s disease: a cross-sectional study of the enroll-HD observational study

<h3>Background</h3> Apathy is one of the most frequently reported psychological symptoms of Huntington’s Disease (HD), and has previously been associated with cognitive, functional and motor impairment in premanifest HD. <h3>Aims</h3> The aim of the current study is to investigate if the relationship between apathy and verbal fluency is mediated by motor scores, depression and functional capacity in premanifest HD. <h3>Methods</h3> Data for the current study extracted from the Enroll-HD observational cohort study. N=859 participants who were classified as being in the pre-manifest stage of HD and having at least ‘mild’ apathy were included in mediation analysis and were aged between 18 to 79 (M= 39.71, SD± 11.67), with 42.3% male and 57.7% female. Participants completed semantic and phonemic fluency tasks, with the clinician administered Problem Behavioural Assessment-short form (PBA-s) assessing apathy. Depression was assessed using the Hospital Anxiety and Depression scale (HADs). Functional status and motor functioning were assessed using the Total Functional Capacity (TFC) and the Total Motor score (TMS) from the United Huntington’s Disease Rating scale (UHDRS). <h3>Results</h3> The indirect effect of apathy on total, semantic and phonemic fluency scores were all significant while the direct effects of apathy on total fluency, semantic and letter fluency were not significant, suggesting that in all the models tested that mediation had occurred. Evidence of sequential mediation was found in total and phonemic fluency models, but not in semantic fluency. <h3>Conclusion</h3> Apathy was indirectly associated with poorer verbal fluency through indirect and sequential mediation. Future research should explore this relationship longitudinally.