But after the group leaves people who fail save versus [insert what suits best in the system you use] are apathic for next 2d6 months. They barely take care of their basic needs. Children won't play, farmers don't work, taverns are closed and bards don't sing.
This mass apathy might have horrible consequences for villages as lords and the church don't get their share anymore. Only few produce food or take care of maintaining the village. At least two months most of the village is unfunctional mess of people who stop living. After two months some of the people will get back to tracks but many stay in their aphatic state for several months.