Although the suppression of thoughts may seem to be an effective solution, this strategy can lead to an exacerbation of the very thought that one is attempting to suppress. This ironic effect is the most obvious unwanted outcome of suppression and has now been investigated empirically for more than two decades. However, the fact that suppression is an effortful process implies that, even when suppression does not lead to an ironic rebound of the unwanted thought, it puts an insidious cognitive load on the individual attempting to suppress. Moreover, whether or not suppression leads to an exacerbation of the unwanted thought, it is rarely successful, and hence adds to the individual's distress. In this article we describe the phenomenon of suppression and consider how it might complicate a range of emotional disorders. Taken together, studies on thought suppression in psychopathology present a more nuanced picture now than was emerging in the early years of its investigation. Some evidence is consistent with the idea that the counterproductive effects of suppression are causally implicated in the disorder, but for the most part a more parsimonious conclusion is that thought suppression acts as a complication of the disorder. In certain disorders, suppression complicates the disorder by leading to an ironic rebound of the unwanted thoughts. In all disorders, the cost of undertaking suppression is a persistent cognitive load, which, in turn undermines the ability to suppress, and hence sets off a cycle of failed expectations and distress.
Hidden Complications 1Much to his annoyance, a thought popped into his mind. It was very clear and very distinct, and he had now come to recognize these thoughts for what they were. His instinct was to resist them. They were the preordained promptings from the dark and locked off parts of his mind. He sat still and ignored the thought furiously. It nagged at him. He ignored it. It nagged at him. He ignored it. It nagged at him. He gave in to it. Douglas Adams, The Restaurant at the End of the Universe (1980, p. 172) Sometimes science fiction can remind us of science fact. In the case of this fantasy novel by Douglas Adams, the fact of which we are reminded is the insistent and inevitable return of an unwanted thought. Thoughts we put out of mind seem to come back with a vengeance that makes us wonder whether we may have gone mad. Now as it happens, the hypothesis that recurrent unwanted intrusive thoughts might be associated with psychopathology has occurred to many psychologists over the years (Clark, 2005;Rachman & De Silva, 1978). This paper reviews research on how the suppression of such unwanted thoughts is related to psychological disorder.The experience of mental disorder is often associated with painful thoughts and feelings and thus will commonly motivate suppression as a reaction (Najmi & Wegner, in press;Wegner, 1989). Most early research on intrusive and obsessive thoughts operated under the assumption that suppression is always reactive in this way, and so ...