DIRT [Danger Ideation Reduction Therapy] for Obsessive Compulsive Checkers: A Comprehensive Guide to Treatment

Lisa D. Vaccaro, Mairwen K. Jones, Ross G. Menzies, and Tamsen St Clare

University of Sydney



DIRT for Checkers is a unique new evidence-based treatment program designed to specifically reduce expectancies of danger or threat in those with Obsessive Compulsive Disorder (OCD) with predominant checking concerns. Unlike many traditional OCD treatments, DIRT is based on the rationale that the therapist should provide as much factual information as possible to decrease the expectancy that harmful events such as the fear of fire, damage, theft, harm to others and other physical losses will follow any failure to check and thus reduce the high dropout rate seen in conventional OCD exposure and response prevention programs. DIRT consists of six discrete treatment components aimed at reducing the number of intrusive thoughts experienced and concurrently allowing the client to successfully change the remaining thoughts and beliefs. The treatment includes attentional focusing, cognitive restructuring, double-checking experiments, corrective information, filmed interviews, probability of catastrophe task. The book includes a resource CD with patient handouts and a DVD of interviews.

DIRT has been shown to be a highly successful treatment package for OCD, able to shift even the most intractable of cases. Randomised control studies have established that DIRT represents a viable alternative to the standard behavioural approach. In addition, DIRT appears to have several potential advantages over behavioural and pharmacological treatments:

  • Unlike in an Exposure and Response Prevention (ERP) program, clients who undergo the DIRT regime are not asked to confront anxiety-provoking (feared) stimuli. This is particularly important since many sufferers either refuse exposure treatment or drop out before completion because of its anxiety-provoking effects.
  • Unlike medication used in the treatment of OCD, DIRT achieves its success without the complication of physical side effects. 
  • DIRT is a highly structured treatment package involving films, information sheets and worksheets which are relatively inexpensive to package and administer.
  • DIRT appears to require relatively few sessions for its therapeutic effect. Substantial reductions in OCD symptomatology have been achieved in as few as six clinical hours.
  • DIRT may prove beneficial for intractable patients who have failed with standard treatments, and for those who exhibit poor insight.

Some DIRT research references:

Drummond, L.M. & Kolb, P. (2008). Obsessive-compulsive contamination fears and anorexia nervosa: The application of the new psycho-educational treatment of Danger Ideation Reduction Therapy (DIRT), Behaviour Change, 25, 44-50.

Govender, S., Drummond, L. M., Menzies, R. G.(2006) Danger Ideation Reduction Therapy for the Treatment of Severe, Chronic and Resistant Obsessive-Compulsive Disorder. Behavioural and Cognitive Psychotherapy. 34(4), 477-480.

Hambridge, J. & Loewenthal, M. (2003). Treating Obsessive Compulsive Disorder: A New Role for Infectious Diseases Physicians? International Journal of Infectious Diseases, 7, 152-155.

Jones, M. K., & Menzies, R. G. (1997a). Danger Ideation Reduction Therapy (DIRT): preliminary findings with three obsessive-compulsive washers. Behaviour Research and Therapy, 35, 955-960.

Jones, M. K., & Menzies, R. G. (1997b). The cognitive mediation of obsessive-compulsive handwashing. Behaviour Research and Therapy, 35, 843-850.

Jones, M. K., & Menzies, R. G. (1998a). Danger Ideation Reduction Therapy (DIRT) for obsessive-compulsive washers. A controlled trial. Behaviour Research and Therapy, 36, 959-970.

Jones, M. K., & Menzies, R. G. (1998b). The role of perceived danger in the mediation of obsessive-compulsive washing. Depression and Anxiety, 8, 121-125.

Krochmalik, A., Jones, M. K., & Menzies, R. G. (2001). Danger Ideation Reduction Therapy (DIRT) for treatment-resistant compulsive washing. Behaviour Research and Therapy, 39, 897- 912.

Krochmalik, A., Jones, M. K., Menzies, R. G., & Kirkby, K. (2004). The Superiority of Danger Ideation Reduction Therapy (DIRT) over Exposure and Response Prevention (ERP) in Treating Compulsive Washing. Behaviour Change, 21, 251-268.

O’Brien, M., Jones M.K, & Menzies, R.G. (2004). Danger Ideation Reduction Therapy (DIRT) for Intractable, Adolescent Compulsive Washing: A Case Study. Behaviour Change, 21, 57–65.

St Clare, T. (2004). Danger Ideation Reduction Therapy (DIRT) for Atypical Obsessive-Compulsive Disorder: A Case Study. Behaviour Change, 21, 186-196.          

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About the Author

Lisa Vaccaro is currently a candidate for a Doctor of Philosophy (PhD) at the University of Sydney. She completed undergraduate and began postgraduate studies at Macquarie University - awarded a Bachelor of Arts (Psychology) in 1998 and a Postgraduate Diploma in Psychology in 1999. Under direction of the late Professor of Surgery - Christopher J. Martin - Lisa was employed to assist the development and conducting of world-class clinical research trials. She was also involved in the establishment of BOPS (Barrett's Oesophagus Patient Support) - an information based patient support group. Lisa is currently involved in numerous research projects into the nature and treatment of obsessive-compulsive disorder.

Dr Mairwen Jones is currently Senior Lecturer in Psychology in the Faculty of Health Sciences, The University of Sydney. Dr Jones completed a Bachelor of Arts with first class honours in psychology in 1992 at the University of Sydney. She was awarded the Australian Psychological Society Prize for first in the year and the Dick Thompson Prize for First Placed Student in Psychology Honours. In 1993 she was awarded an Australian Postgraduate Research Award for her doctoral project. Mairwen has been Acting Director of the Anxiety Disorders Clinic and Clinical Consultant to the clinic at the University of Sydney and is currently Clinic Head. She is Chair of the Faculty's Mental Health Research Team. and has been a chief investigator on a number of successful competitive grants which have funded research into the nature and treatment of obsessive-compulsive disorder. Her research has been published in journals and book chapters and has been presented at numerous prestigious international and local events. She is an author of Danger Ideation Reduction Therapy (DIRT) for obsessive-compulsive washers: A comprehensive guide to treatment. Finally, her research has been of local and international interest in the media and she has conducted more than 20 radio and/or newspaper interviews in recent years.

Associate Professor Ross G. Menzies has been providing CBT for OCD, phobias, anxiety and depression in the inner-west of Sydney for over 15 years. He is currently Associate Professor of Psychology in the Discipline of Behavioural and Community Health Sciences at the University of Sydney. In 1991, he was appointed founding Director of the Anxiety Disorders Clinic, Faculty of Health Sciences, University of Sydney. He is an Advisory Board Member of the Sydney Anxiety Disorders Practice and is the Clinical Director of Anxpsych, an organisation bringing anxiety management skills to the corporate sector. He is the Head and Director of the Anxiety and Stress Research Group, the University of Sydney, and the editor of Australia's national CBT scientific journal, Behaviour Change. Professor Menzies holds several other honorary appointments and is the senior clinical supervisor for many psychologists and departments across Sydney. He has been the overseas expert trainer in cognitive behaviour therapy at the National University of Singapore and is the co-editor of the 2003 International Handbook on OCD for the prestigious Wiley Series in clinical psychology. In addition to his work on OCD in adulthood, he has considerable experience with child and adolescent forms of the disorder. He is the Clinical Patron of the Tasmanian Support Network for Child and Adolescent OCD. He is an active researcher with numerous national competitive grants. He has produced over 100 international journal manuscripts, books and book chapters and is regularly invited to speak at conferences and leading universities and institutions around the world. He is an author of Danger Ideation Reduction Therapy (DIRT) for obsessive-compulsive washers: A comprehensive guide to treatment. He continues to attract patients from across metropolitan Sydney, rural NSW, interstate and from overseas, with many individuals and families travelling thousands of kilometres to receive treatment at his private practice.


Tamsen St Clare obtained her honours degree in Psychology and her Masters degree in Clinical Psychology from the University of Sydney. She is currently working as a Clinical Psychologist in private practice. She is formerly Senior Clinical Psychologist and Head of the Sydney West Area Health Service's Anxiety Treatment and Research Unit, and Clinical Director of the University of Sydney Anxiety Disorders Clinic. She is a member of the Anxiety Disorders Advisory Committee of the NSW Mental Health Association. Tamsen has published several peer-reviewed journal articles on obsessive compulsive disorder, and has extensive clinical experience with the DIRT package, having utilised it in research, public health, and private practice settings. She is first author of Danger Ideation Reduction Therapy (DIRT) for obsessive-compulsive washers: A comprehensive guide to treatment.

Table of Contents

  • Chapter 1 - Introduction To DIRT
  • Chapter 2 - Treatment Rationale
  • Chapter 3 - Attentional Focusing
  • Chapter 4 - Cognitive Restructuring
  • Chapter 5 - The Double Checking Experiments
  • Chapter 6 - Corrective Information
  • Chapter 7 - Filmed Interviews
  • Chapter 8 - Probability Of Catastrophe Task
  • Chapter 9 - Ending Therapy: The Final Session