Intrusive Thoughts in Clinical Disorders: Theory, Research, and Treatment
In his new book, David Clark has put together an analysis of different psychiatric conditions on the basis of a shared feature, unwanted intrusive thoughts. Utilizing the contributions of researchers in Canada, the United Kingdom, and the United States, he provides an update of how cognitive psychology currently views the etiology and treatment of mood, anxiety, and psychotic disorders, by looking at the phenomenon of intrusive thoughts. Chapters of the book are devoted to the phenomenon of intrusive thoughts in depression, posttraumatic stress disorder, generalized anxiety disorder, psychosis, insomnia, and sexual offending behaviors. The book opens with a review of normal and abnormal cognition and with the editor's definition of intrusive thoughts. It closes with a summary of how the phenomenon of intrusive thoughts can further our understanding of psychiatric illness and treatment and with a caution about the limitations of the research in this area.
Dr. Clark defines intrusive thoughts as distinct thoughts, images, or impulses that enter conscious awareness on a recurrent basis, are difficult to control, and interfere with ongoing cognitive and behavioral activity. The first chapter of the book deals with intrusive thoughts of individuals with no mental illness. According to the book, research on nonclinical populations reports the occurrence of intrusive thoughts among 80 to 90 percent of those sampled. The clinical populations that experience intrusive thoughts differ from the nonclinical in the degree of distress associated with the thoughts and the amount of energy devoted to dealing with them. The book forces the reader to think about the factors that control consciousness and about how little science knows about how thoughts are generated and experienced.
The chapters of the book are devoted to specific clinical conditions and include extensive research data. The chapters devoted to obsessive-compulsive disorder (OCD), depression, insomnia, and anxiety give cognitive explanations for these disorders and use central constructs such as appraisal, metacognition, and thought suppression. Appraisal is the process by which an individual assigns a negative meaning to a particular intrusive thought. Metacognition is the phenomenon of thinking about and explaining one's own thoughts. Thought suppression is a cognitive process by which an individual tries to shut out intrusive thoughts, which most often leads to a counterproductive increase in distressing thoughts. For example, as the book explains, OCD may involve an intrusive thought about homicide that becomes appraised by an individual to signify that he or she is immoral and needs to suppress such thoughts. These constructs are valuable to mental health professionals who treat individuals with these disorders, and they constitute a useful framework for understanding current cognitive therapies.
Cognitive theories in psychotic disorders and in sexual disorders are also presented in the book. Therapists will welcome new approaches to working with psychotic individuals, although it is not clear that the book fully acknowledges the complexities of psychotherapy with this population. Cognitive-behavioral therapy has become a treatment modality for patients with paraphilic disorders who commit sex offenses. The book reflects the importance of treating factors that may lead to relapse. However, the complexity and heterogeneity of sexual disorders merits more space than the book devotes to this area.
David Clark has succeeded in putting together a comprehensive summary of cognitive theory on intrusive thoughts, with information that will be useful to researcher and clinician alike. It is compelling in its ability to stimulate the reader to think about how the thoughts that underlie disorders are shaped and controlled. Researchers will appreciate the descriptions of research tools and methods. Clinicians will benefit from the ample attention paid to the clinical applications of current theory. However, this book appears to be most suited for those with specific research and practice interests in cognitive psychology and therapy and not to the therapist who is looking for a more general guide to cognitive-behavioral therapies.
