[New Era in Neurodegenerative Disease: Therapeutic Advances and Social and Ethical Challenges]

Recent advances in molecular genetics and cellular modeling have begun to transform the landscape of neurodegenerative diseases, long regarded as "incurable and poorly understood." The identification of causative genes and disease-associated proteins, together with analytical technologies such as induced pluripotent stem (iPS) cell-based platforms, has deepened our understanding of disease mechanisms and clarified therapeutic targets. In parallel, emerging targeted therapies-including nucleic acid-based treatments and therapeutic antibodies-have demonstrated levels of clinical benefit previously considered unrealistic, such as slowing disease progression or reducing relapse rates. These developments signal the arrival of a new era in the treatment of intractable neurological disorders. At the same time, these advances raise a wide range of issues, including challenges related to the implementation and long-term sustainability of such treatments, national-level debate regarding drug pricing and healthcare expenditure, and ethical concerns associated with the broader use of genetic testing. This article summarizes these recent therapeutic developments and the accompanying social and ethical issues that warrant careful attention in this evolving era.