Behavioural variant frontotemporal dementia (bvFTD) is characterized by an absence of obvious cognitive impairment and presence of symptoms such as disinhibition, social inappropriateness, personality changes, hyper-sexuality, and hyper-orality. Affected individuals do not feel concerned enough about their actions to be deterred from violating social norms, and their antisocial behaviours are most likely caused by the neurodegenerative processes in the frontal and anterior temporal lobes. BvFTD patients present a challenge for the traditional notion of autonomy and the medical and criminal justice (...) systems. Antisocial behaviour is often the earliest recognized manifestation of bvFTD. Given that the symptoms are not specific and that atrophy of the frontal lobes is only observable with structural neuroimaging in the later stages of the disease, it is hard to ascertain their autonomy. Recently proposed re-conceptualizations of autonomy (Dworkin’s, Jaworska’s, and Dubljević’s) can, however, be sufficiently redefined to provide explicit rules and offer nuanced guidance in such cases. A combination of notions of autonomy gives the most nuanced guidance with three modifications: 1) including socio-moral judgement in the notion of “normal cognitive competence,” 2) excluding in-principle un-endorsable ideals from the notion of “capacity to value,” and 3) redefining ideal-typical degrees of compulsion (mild, severe, and total). (shrink)