What happens in an organization when communication is limited?

communication controls, motivates, provides release, and facilitates decision making. What happens in an organization when communication is limited? How does downward and upward communication affect the functions mentioned above?What happens in an organization when communication is limited?
Often times it is not practice in a corporation so treachery can take place and to keep everybody on edge. It is a purposeful technique. It is this: "The Mushroom Syndrome" or keep them in the dark and feed them horse ****.