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Biomedical subjects

David M Clark

Publications and source records attributed to David M Clark.

27 records · Page 2Linked to original sources

Internal versus external attention in social anxiety: an investigation using a novel paradigm.

Several cognitive models propose that social anxiety is associated with increased self-focused attention. Indirect evidence for this hypothesis has been provided by questionnaire studies, and by cognitive psychology paradigms that have demonstrated reduced processing of external information during feared social-evaluative situations. However, no studies have simultaneously measured on-line attention to internal and external events. A probe detection task that aimed to measure the balance of attention between internal and external stimuli was developed. High and low socially anxious individuals were instructed to detect two probes. The external probe was superimposed on pictures of faces (happy, neutral, angry) or household objects that were presented on a VDU. The 'internal' probe was a pulse to the finger which participants were led to believe represented significant changes in their physiology. Compared to low speech anxious individuals, high speech anxious individuals showed an internal attentional bias, that was specific to conditions of social-evaluative threat.

Adult↗

Self-images play a causal role in social phobia.

Patients with social phobia often experience negative self-images in social situations. The current study investigated whether negative self-images have a causal role in maintaining social phobia. Patients with social phobia participated twice in a conversation with a stranger, once whilst holding their usual negative self-image in mind and once whilst holding a less negative (control) self-image in mind, with order counterbalanced across participants. Compared to the control image condition, when participants held the negative image in mind they experienced greater anxiety, rated their anxiety symptoms as being more visible, and rated their performance as poorer. An assessor who did not know which image was being held also rated participants' anxiety as more evident and their behaviour as less positive when the negative image was being held in mind. Finally, when participant and assessor ratings were compared, participants underestimated their performance and overestimated the visibility of their anxiety to a significantly greater extent in the negative imagery condition. Taken together, these results support the hypothesis that negative self-imagery has a causal role in maintaining social phobia.

Adult↗

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%.

Adult↗

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

Adult↗

Information processing in social phobia.

Cognitive theories suggest that information processing biases play a central role in the development and maintenance of emotional disorders. The present article reviews recent studies of information processing biases in social phobia and considers the significance of the findings for understanding the persistence of the condition. Taken together, the studies suggest that social phobia is characterized by biases in the following: interpretation of external social events; detection of negative responses from other people; the balance of attention between external and self-processing; the use of internal information to make inferences about how one appears to others; recall of negative information about one's perceived, observable self; and by a variety of problematic anticipatory and post-event types of processing. If such biases play a role in maintaining social anxiety, experimental manipulation of the biases should modulate anxiety responses. Several recent studies have confirmed this prediction, but further research is required. Methodological limitations of existing information processing studies are highlighted. Finally, possible neurobiological correlates are discussed and suggestions are made for future attempts to link neurobiology and cognitive psychology.

Attention↗

Cognitive processing, memory, and the development of PTSD symptoms: two experimental analogue studies.

Memory deficits are implicated in the development of posttraumatic stress disorder (PTSD). Intentional recall of trauma memories is frequently disorganised or incomplete, whilst involuntary memory fragments are easily triggered by perceptual cues. Ehlers and Clark (Behaviour Research and Therapy 38 (2000) 319-345) propose that a predominance of data-driven processing (i.e., processing sensory impressions) during the trauma contributes to the development of this memory pattern, and therefore, predicts PTSD symptoms after trauma. Two experimental studies examined these hypotheses. Student volunteers viewed a distressing videotape as an analogue for a traumatic event. In Study 1, cognitive processing was manipulated; in Study 2, extreme scorers on a processing screening questionnaire were pre-selected. The results indicated that data-driven processing is associated with the development of PTSD-like memories and analogue symptoms.

Adult↗

Community based cognitive therapy in the treatment of posttraumatic stress disorder following the Omagh bomb.

Studies in academic research centres with selected patients have shown that several cognitive behaviour therapies are effective in the treatment of PTSD following traumas affecting individuals or small groups. Little information is available on the extent to which these positive findings will generalize to more routine clinical settings with less selected patients or to a trauma that affects a whole community. The present study addresses these generalization issues. A consecutive series of 91 patients with PTSD resulting from a car bomb which exploded in the centre of Omagh, Northern Ireland in August 1998 were treated with cognitive therapy, along lines advocated by Ehlers and Clark (2000). There were no major exclusion criteria and 53% of patients had an additional axis I disorder (comorbidity). Therapists were NHS staff with heavy caseloads and modest prior training in CBT for PTSD. A brief training in specialist procedures for PTSD was provided. Patients received an average of eight treatment sessions. Significant and substantial improvements in PTSD were observed. Degree of improvement was comparable to that in previously reported research trials. Comorbidity was not associated with poorer outcome, perhaps because comorbid patients were given more sessions of treatment (average 10 vs 5 sessions). Patients who were physically injured improved less than those who were not physically injured. Overall, the results indicate that the positive findings obtained in research settings generalize well to a frontline, non-selective service.

Adolescent↗

Anticipatory processing in social anxiety: two pilot studies.

Two studies investigating the cognitive processes associated with anticipatory social anxiety are reported. Study 1 used a semi-structured interview to compare high and low socially anxious individuals ( [Formula: see text] per group) in terms of their reported mental processes during periods of anticipatory social anxiety. Study 2 investigated the anxiety inducing effects of the mental processes that were shown to be characteristic of high socially anxious individuals in Study 1. Prior to giving a speech, high and low socially anxious individuals ( [Formula: see text] per group) either engaged in these processes or performed a distraction task. The results of Study 1 were broadly consistent with Clark and Wells' (In: R.G. Heimberg, M. Liebowitz, D.A. Hope, F.R. Schneier (Eds.), Social phobia: Diagnosis, Assessment and Treatment (pp. 69-93). New York: Guilford Press, 1995) hypotheses about the nature of anticipatory processing in social anxiety. Study 2 showed that, compared to distraction, engaging in the mental processes characteristic of high socially anxious individuals was associated with sustained elevations of anticipatory anxiety in both high and low socially anxious individuals, and led to higher levels of peak anxiety during the speech. The findings suggest that high and low socially anxious individuals show systematic differences in their mental processes prior to a stressful social event, and are consistent with the suggestion that these differences play an important role in sustaining anticipatory anxiety.

Adolescent↗