Can you tell me if a girl takes risperdal, will her breasts become larger?

Maybe: Risperdal primarily works by blocking dopamine. Dopamine happens to work in a negative feedback loop with prolactin. That means, as the Dopamine level goes down, prolactin levels can rise -- sometimes to levels where breast tissue can start to evolve and even produce milk, even in males! The GOOD news is it is all completely reversible. Once med is removed, loop resets itself, tissues go back. : )