Cognitions are attitudes or assumptions schemata are attitudes or assumptions. Cognitions are verbal or pictorial events in ones stream of consciousness. Cognitions are based on schemata developed from previous experiences. Cognitive therapy is an active, directive, time-limited, structured approached used to treat a variety of psychiatric disorders. It is based on the underlying theoretical principle that how people feel and behave is largely determined by the way in which they think about the world and their place in the world. It involves work by Aaron Beck and Albert Ellis. Cognitive therapists helps clients to change the way they think and therefore reduce symptoms. Clients' are taught to callenge their own negative thinking to substitute positive thoguhts.