What happened to Dana in Ghostbusters?

In the original "Ghostbusters" film, Dana Barrett, played by Sigourney Weaver, becomes possessed by a demonic entity called Zuul after encountering supernatural phenomena in her apartment. This possession leads her to become a key figure in the Ghostbusters' battle against the ancient entity, Gozer. The Ghostbusters ultimately rescue her from this fate, restoring her to her normal self by defeating Gozer and breaking the possession. Dana's character serves as both a romantic interest for Peter Venkman and a central figure in the film's supernatural conflict.