The abuse of a sedative-laced vape liquid called “zombie cigarettes” has been increasing among youths in southern Japan, with investigative authorities stepping up vigilance against its potential spread nationwide.By the end of September, 10 people, mostly in their teens and 20s, had been arrested in Okinawa prefecture for possessing etomidate. In May, the Japanese government designated the substance, which is known to depress cerebellar neuronal activity essential for body coordination, as a...