A quick reference guide to defeating Obsessive Compulsive Disorder (OCD) using Exposure and Response Prevention (ERP), a type of Cognitive Behavioural Therapy (CBT) that is recommended by the United Kingdom's National Institute for Health and Care Excellence (NICE) in their guidelines for treating OCD. Catherine is a Physiotherapist by background and also has over 15 years’ experience of living with Obsessive Compulsive Disorder (OCD). In 2017, Catherine’s OCD became so incapacitating to her daily life that she was kindly admitted to the inpatient unit at the National OCD/BDD Service run by South West London and St Georges Mental Health NHS Trust. This is a service provided for those with the most severe or enduring OCD in the United Kingdom and is led by Dr Lynne Drummond, an expert in the field of OCD. The book was initially written as an aide memoir for Catherine to remember the evidence-based techniques she was taught during her time at the National OCD/BDD Service which she found helped to improve her OCD symptoms. However, in doing this, Catherine realised that these may also benefit others in their fight against OCD, and so this book has been produced. Catherine would like to share her experiences of the strategies that benefitted her with others affected by OCD, including sufferers, their families, friends and carers, and also with healthcare professionals who may be working with, or who are in training to work with, people who have OCD. Hopefully the book will help to ensure that those affected by OCD are given appropriate advice and tools to help them to defeat their OCD. Catherine has also been a member of the charity OCD-UK for a number of years and has attended numerous conferences hosted by the charity, which include sessions led by well respected experts in OCD, such as Professor Paul Salkovskis. The book has been specifically designed to be a pocket sized reference guide that is accessible to as many readers as possible and can be kept in a pocket or bag for easy and quick access when information is required. The book also has wire binding to enable it to be kept open on useful pages as desired by the reader for quick access. Importantly, the book has been printed on waterproof paper to enable it to be wiped with an antibacterial wipe if this is required in order for OCD sufferers to access it... the book will show you how you can overcome this! This also enables the book to be more durable and help to protect it against some damage, including tears. Catherine would like to wish readers all the best in overcoming their OCD symptoms, or in helping others to overcome their symptoms. She would also like to provide encouragement and optimism that OCD symptoms can improve by using Exposure and Response Prevention (ERP), a type of Cognitive Behavioural Therapy (CBT) recommended by the United Kingdom’s National Institute for Health and Care Excellence (NICE) in their guidelines for treating OCD.