P. De Silva

Abnormal and normal obsessions

Abstract Three related, exploratory studies were carried out in order to ascertain the occurrence and nature of normal obsessions, and to relate them to abnormal obsessions. The subjects included 8 obsessional patients, and up to 124 non-clinical subjects. Broadly, the findings were that normal obsessions are a common experience and they resemble the form of abnormal obsessions. They also show some notable similarities of content. However normal and abnormal obsessions differ in several respects, including frequency, duration, intensity and consequences, among others. With repeated practice, the frequency, duration and discomfort of obsessions are observed to decrease. Overall, the findings are considered to be consistent with the noxious stimulus cum habituation theory.

The spontaneous decay of compulsive urges

Abstract An experiment was carried out on eleven obsessional patients who complained of compulsive checking rituals. Exposure to a provoking situation produced marked anxiety/discomfort and strong urges to check. With minor exceptions, execution of the appropriate ritual was followed by marked decreases in anxiety/discomfort and urges. The results were interpreted as being consistent with an anxiety/discomfort reduction hypothesis. The spontaneous decay of anxiety/discomfort and urges was observed during a 3-hr response-prevention period. The greatest part of the discomfort and compulsive urges dissipated within an hour. Discomfort scores and urges ran a closely parallel course. Few resurgences of discomfort or urges were observed during the 3-hr observation period, and there was little sign of displacement checking activity.

Does escape behaviour strengthen agoraphobic avoidance? A preliminary study

Abstract Two groups of agoraphobic patients were treated with one of two forms of exposure-based therapy. In one group, the patients stayed in the target situation until their self-rated anxiety dropped by half (Endurance condition). In the other, the patients were required to leave the fear situation when their anxiety reached a high pre-set level, without waiting for anxiety to drop (Escape condition). The patients in both groups improved, in contrast to those in a Waiting-list control group. There were no significant differences between the two treated groups. The results are discussed in terms of Mowrers theory of fear and avoidance from which it can be predicted that patients in an ‘escape condition’ should not improve. Contrary to a Mowrerian prediction, patients who were taught to escape when still fearful, did not show increased avoidance behaviour.

Phobias and preparedness: replication and extension

Abstract Phobias of a clinical population in Sri Lanka (N = 88) were rated for their biological preparedness. As in previous studies of preparedness, the vast majority of the phobias were rated as highly prepared. No relationship was found between preparedness and whether the onset was sudden or gradual.

Is exposure a necessary condition for fear-reduction?

Abstract In most of the effective techniques for reducing fear, exposure to the fear-provoking stimulus is a prominent feature. It is argued that in many circumstances, engaged exposure to the fear stimuli is a sufficient condition for fear-reduction, but there is no good reason for supposing that such exposure is a necessary condition for fear-reduction. Seven examples of fear-reduction apparently taking place in the absence of exposure are used to illustrate the argument. Some theoretical and practical consequences of the argument are introduced.

Human food aversions: nature and acquisition.

Abstract This paper reports a two-stage investigation of human food aversions. A questionnaire survey was carried out with a sample of normal adults, followed by an interview study of a sub-sample of the positive respondents. Data on frequency, strength, avoidance, modality, content, duration, age of acquisition, mode of acquisition, and generalization are reported. Observations are made on the similarities between those aversions that fit the definition of conditioned food aversions, and those that do not. Implications for future research are discussed, and the need for the study of the whole range of human food aversions is emphasized.

Obsessive-compulsive disorder : theory, research and treatment

About the Editors. List of Contributors. Preface. Acknowledgements. Section I - The Nature of OCD. Chapter 1 - The Classification and Diagnosis of OCD (A. Krochmalik and R. Menzies). Chapter 2 - The Phenomenology of OCD (P. de Silva). Section II - Theoretical Accounts of OCD. Chapter 3 - Neuropsychological Models of OCD (I. Frampton). Chapter 4 - Cognitive-behavioural Theory of OCD (P. Salkovskis and J. McGuire). Chapter 5 - Repetitive and Iterative Thinking in Psychopathology: Anxiety-inducing Consequences and a Mood-As-Input Mechanism (G. Davey, et al.). Chapter 6 - Personality and Individual Differences in OCD (A. Macdonald). Section III - Clinical Presentations and Subtypes of OCD. Chapter 7 - Obsessive-compulsive Washing (M. Jones and A. Krochmalik). Chapter 8 - Compulsive Checking (S. Rachman). Chapter 9 - Compulsive Hoarding (R. Frost and T. Hartl). Chapter 10 - Primary Obsessional Slowness (S. Rachman). Chapter 11 - Obsessions, Ruminations and Covert Compulsions (P. de Silva). Ch apter 12 - Atypical Presentations (D. Einstein and R. Menzies). Chapter 13 - The Obsessive-compulsive Spectrum and Body Dysmophic Disorder (D. Veale). Section IV - Approaches to Assessment and Treatment in OCD. Chapter 14 - Assessment Procedures (T. St. Clare). Chapter 15 - Exposure and Response Prevention for OCD (M. Kyrios). Chapter 16 - Cognitive Therapy for OCD (M. Marks). Chapter 17 - Pharmacological and Neurosurgical Treatment of OCD (M. McDonough). OCD in Children and Adolescents (R. Shafran). Chapter 19 - The Management of Treatment-resistant Cases and other Difficult Clients (M. Bruch and A. Prioglio). Section V - Professional Issues. Chapter 20 - Training, Resources and Service Provision (L. Harris and R. Menzies). References. Author Index. Subject Index.

The modification of human food aversions: a preliminary study.

Food aversions in normal adult humans are quite common, but they rarely present a clinical problem. The present report describes the modification of food aversions in a series of adults. The strategy used was simple in vivo graded exposure, with modelling and verbal reinforcement. The success of the strategy suggests that human food aversions are modifiable with relatively simple techniques.