The precise role of cognitive processes is yet to be determined. It is not clear whether faulty cognitions are a cause of psychopathology or a consequence of it.
Sometimes these negative cognitions are, in fact, a more accurate view of the world: depressive realism.
Cognitive theories lend themselves to testing. When experimental subjects are manipulated into adopting unpleasant assumptions or thoughts, they become more anxious and depressed (Rimm & Litvak, 1969).