David M. Clark

A cognitive model of posttraumatic stress disorder.

Posttraumatic stress disorder (PTSD) is a common reaction to traumatic events. Many people recover in the ensuing months, but in a significant subgroup the symptoms persist, often for years. A cognitive model of persistence of PTSD is proposed. It is suggested that PTSD becomes persistent when individuals process the trauma in a way that leads to a sense of serious, current threat. The sense of threat arises as a consequence of: (1) excessively negative appraisals of the trauma and/or its sequelae and (2) a disturbance of autobiographical memory characterised by poor elaboration and contextualization, strong associative memory and strong perceptual priming. Change in the negative appraisals and the trauma memory are prevented by a series of problematic behavioural and cognitive strategies. The model is consistent with the main clinical features of PTSD, helps explain several apparently puzzling phenomena and provides a framework for treatment by identifying three key targets for change. Recent studies have provided preliminary support for several aspects of the model.

The Posttraumatic Cognitions Inventory (PTCI): Development and validation

This article describes the development and validation of a new measure of trauma-related thoughts and beliefs, the Posttraumatic Cognitions Inventory (PTCI), whose items were derived from clinical observations and current theories of post-trauma psychopathology. The PTCI was administered to 601 volunteers, 392 of whom had experienced a traumatic event and 170 of whom had moderate to severe posttraumatic stress disorder (PTSD). Principal-components analysis yielded 3 factors: Negative Cognitions About Self. Negative Cognitions About the World, and Self-Blame. The 3 factors showed excellent internal consistency and good test-retest reliability; correlated moderately to strongly with measures of PTSD severity, depression, and general anxiety: and discriminated well between traumatized individuals with and without PTSD. The PTCI compared favorably with other measures of trauma-related cognitions, especially in its superior ability to discriminate between traumatized individuals with and without PTSD.

Cognitive Therapy Versus Fluoxetine in Generalized Social Phobia: A Randomized Placebo-Controlled Trial

Sixty patients meeting Diagnostic and Statistical Manual of Mental Disorders (4th ed.: American Psychiatric Association, 1994) criteria for generalized social phobia were assigned to cognitive therapy (CT), fluoxetine plus self-exposure (FLU + SE), or placebo plus self-exposure (PLA + SE). At posttreatment (16 weeks), the medication blind was broken. CT and FLU + SE patients then entered a 3-month booster phase. Assessments were at pretreatment, midtreatment, posttreatment, end of booster phase, and 12-month follow-up. Significant improvements were observed on most measures in all 3 treatments. On measures of social phobia, CT was superior to FLU + SE and PLA + SE at midtreatment and at posttreatment. FLU + SE and PLA + SE did not differ. CT remained superior to FLU + SE at the end of the booster period and at 12-month follow-up. On general mood measures, there were few differences between the treatments

A prospective investigation of the role of cognitive factors in persistent Posttraumatic Stress Disorder (PTSD) after physical or sexual assault

The effectiveness of psychological treatments for PTSD is likely to be enhanced by improved understanding of the factors involved in maintaining the disorder. Ehlers and Clark [A cognitive model of persistent posttraumatic stem disorder Behav. Res. Ther. 38 (2000) 319-345] recently proposed a cognitive model of maintenance. The current study aimed to investigate several cognitive factors highlighted in Ehlers and Clarks model using a prospective design. Fifty-seven victims of physical or sexual assault participated in the study. Cognitive factors were assessed within 4 months of assault and victims were followed-up 6 and 9 months after the assault. Cognitive variables which significantly predicted PTSD severity at both follow-ups were: cognitive processing style during assault (mental defeat, mental confusion, detachment); appraisal of assault sequelae (appraisal of symptoms, perceived negative responses of others, permanent change); negative beliefs about self and world; and maladaptive control strategies (avoidance/safety seeking). Relationships between early appraisals, control strategies, and processing styles and subsequent PTSD severity remained significant after statistically controlling for gender and perceived assault severity. These findings support the cognitive model of PTSD proposed by Ehlers and Clark and suggest that effective treatment will need to address these cognitive factors.

Cognitive therapy versus exposure and applied relaxation in social phobia: a randomized controlled trial.

A new cognitive therapy (CT) program was compared with an established behavioral treatment. Sixty-two patients meeting Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) criteria for social phobia were randomly assigned to CT, exposure plus applied relaxation (EXP = AR), or wait-list (WAIT). CT and EXP = AR were superior to WAIT on all measures. On measures of social phobia, CT led to greater improvement than did EXP = AR. Percentages of patients who no longer met diagnostic criteria for social phobia at posttreatment-wait were as follows: 84% in CT, 42% in EXP = AR, and 0% in WAIT. At the 1-year follow-up, differences in outcome persisted. In addition, patients in EXP = AR were more likely to have sought additional treatment. Therapist effects were small and nonsignificant. CT appears to be superior to EXP = AR in the treatment of social phobia.

Cognitive processes in social phobia

Social phobics, anxious controls and non-patient controls took part in a brief videotaped conversation with a stooge in order to investigate the cognitive model of social phobia. Thoughts, behaviour, and attention during the conversation were assessed. Compared to the control groups, social phobics had more negative self-evaluative thoughts, performed less well, and systematically underestimated their performance. There were no differences in attention between the three groups. Content analysis of thought sampling data from the conversation, and from three hypothetical situations, revealed that few of the negative thoughts reported by social phobics explicitly mentioned evaluation by other people. This suggests that social phobics may not closely monitor other peoples responses in social situations and hence that their thoughts are not data driven. The results are discussed in relation to the cognitive model of social phobia and suggestions are made for improvements in the treatment of social phobia.

Posttraumatic stress disorder following assault: the role of cognitive processing, trauma memory, and appraisals

Two studies of assault victims examined the roles of (a) disorganized trauma memories in the development of posttraumatic stress disorder (PTSD), (b) peritraumatic cognitive processing in the development of problematic memories and PTSD, and (c) ongoing dissociation and negative appraisals of memories in maintaining symptomatology. In the cross-sectional study (n = 81), comparisons of current, past, and no-PTSD groups suggested that peritraumatic cognitive processing is related to the development of disorganized memories and PTSD. Ongoing dissociation and negative appraisals served to maintain PTSD symptoms. The prospective study (n = 73) replicated these findings longitudinally. Cognitive and memory assessments completed within 12-weeks postassault predicted 6-month symptoms. Assault severity measures explained 22% of symptom variance; measures of cognitive processing, memory disorganization, and appraisals increased prediction accuracy to 71%.

Improving access to psychological therapy: Initial evaluation of two UK demonstration sites

Recently the UK Government announced an unprecedented, large-scale initiative for Improving Access to Psychological Therapies (IAPT) for depression and anxiety disorders. Prior to this development, the Department of Health established two pilot projects that aimed to collect valuable information to inform the national roll-out. Doncaster and Newham received additional funds to rapidly increase the availability of CBT-related interventions and to deploy them in new clinical services, operating on stepped-care principles, when appropriate. This article reports an evaluation of the new services (termed ‘demonstration sites’) during their first thirteen months of operation. A session-by-session outcome monitoring system achieved unusually high levels of pre to post-treatment data completeness. Large numbers of patients were treated, with low-intensity interventions (such as guided self-help) being particularly helpful for achieving high throughput. Clinical outcomes were broadly in line with expectation. 55–56% of patients who had attended at least twice (including the assessment interview) were classified as recovered when they left the services and 5% had improved their employment status. Treatment gains were largely maintained at 10 month follow-up. Opening the services to self-referral appeared to facilitate access for some groups that tend to be underrepresented in general practice referrals. Outcomes were comparable for the different ethnic groups who access the services. Issues for the further development of IAPT are discussed.

Anxiety disorders: why they persist and how to treat them.

Anxiety disorders are characterised by distorted beliefs about the dangerousness of certain situations and/or internal stimuli. Why do such beliefs persist? Six processes (safety-seeking behaviours, attentional deployment, spontaneous imagery, emotional reasoning, memory processes and the nature of the threat representation) that could maintain anxiety-related negative beliefs are outlined and their empirical status is reviewed. Ways in which knowledge about maintenance processes has been used to develop focussed cognitive therapy programmes are described and evaluations of the effectiveness of such programmes are summarized. Finally, ways of identifying the effective ingredients in cognitive therapy programmes are discussed.

Social phobia: The role of in-situation safety behaviors in maintaining anxiety and negative beliefs

One of the puzzles surrounding social phobia is that patients with this problem are often exposed to phobic situations without showing a marked reduction in their fears. It is possible that individuals with social phobia engage in behaviors in the feared situation that are intended to avert feared catastrophes but that also prevent disconfirmation of their fears. This hypothesis was tested in a single case series of eight socially phobic patients. All patients received one session of exposure alone and one session of exposure plus decrease in “safety” behaviors in a counterbalanced within-subject design. Exposure plus decreased safety behaviors was significantly better than exposure alone in reducing within-situation anxiety and belief in the feared catastrophe. Other factors that may moderate exposure effects are also discussed.