Obsessive-Compulsive Disorder - A Summary

Obsessive-Compulsive Disorder (OCD) is a highly prevalent and disabling psychiatric disorder affecting close to 2% of the population. It is characterised by obsessions and compulsions. Obsessions are intrusive, distressing, recurrent thoughts or mental images that sufferers usually recognise as their own. They can take many forms, including fears around germs and contamination, accidental injury befalling loved ones, doors being left unlocked, things not being touched the right number of times or the right way, or having unacceptable thoughts.

Compulsions are repetitive behavioural or mental acts that sufferers do to suppress or neutralise the distress caused by the obsessions. This may involve excessive de-contaminating or hand-washing, asking others for reassurance, checking doors and locks, repeating actions or phrases until feels “just right”, as well as mentally saying prayers, reviewing and erasing to neutralise obsessional thoughts.

While unwanted thoughts are quite common in the non-clinical population, it moves onto a disorder when the obsessional thoughts and associated compulsions lead to significant impact on the person's everyday function, significant distress, and take up many hours per day.

In terms of classification, OCD was previously classified as an anxiety disorder but the most recent edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) has moved OCD into its own category of Obsessive-Compulsive and Related Disorders (OCRD) to reflect some distinct characteristics not seen in other anxiety disorders, as well as the overlap between OCD and several other disorders, such as skin-picking (dermatillomania) and hair-pulling (trichotillomania).

It is common for people with OCD to suffer other psychiatric disorders as well, including generalised anxiety disorder, panic disorder, ADHD, and depression. For some people, the OCD occurs first, and becomes so disabling and restricting to their life that they become depressed after.

One third of OCD cases begin before adolescence, with the other two thirds usually occurring in teenage and young adult years. The exact cause of OCD is unknown, although it is likely due to a combination of genetic and environmental factors. It often has a waxing and waning pattern, flaring during stressful times. Furthermore, the types of obsessions can also change over time. Disappointingly, many people take years to achieve an accurate diagnosis. This may be due to shame and stigma, the variable nature of the disorder, and poor awareness in the public and the health professions. This limits access to appropriate treatment.

While OCD was historically considered intractable, new psychological and pharmacological advances from the mid 1960’s has meant that effective treatments are available. Mild-moderate cases can be treated with psychological therapies such as Cognitive-Behavioural Therapy (CBT) and Exposure-Response Prevention (ERP). Cognitive therapy addresses misinterpretations between obsessive thoughts and unhelpful beliefs, and emotional and physical consequences. After these are plotted, the therapist helps the patient find and challenges the distortions in those thoughts and beliefs, which can then assist with resisting compulsions. ERP involves gradually exposing the patient to triggering situations and thoughts in small, controlled amounts that leads to a bit of discomfort, whilst simultaneously restricting or delaying compulsions. With repeated controlled and prolonged exposures, the patient's anxious response decreases over time. This is also called habituation and it is similar to learning to a ride a bicycle for the first time. Eventually, the patient can progress to more difficult exposure tasks in a gradual, stepped manner, and learn that compulsion are unnecessary

The Melbourne Clinic offers a three-week, group inpatient program for OCD. This program has run for decades and is the only one in Australia. It offers intensive CBT and ERP with highly trained therapists with experience in OCD. The Melbourne Clinic has also recently launched an OCD day program for outpatients.

For moderate-severe cases of OCD, psychological therapies may not be sufficient. These patients may also need medications to help reduce their anxiety and enhance their conscious learning so that they can do the CBT and ERP effectively. The first line medications are the Selective Serotonin Reuptake Inhibitors (SSRI), such as fluoxetine and sertraline. These are usually required at higher doses to be effective, when compared to the treatment of other anxiety disorders.

There is ongoing research into the treatment of OCD, including using Transcranial Magnetic Stimulation (TMS) and Deep Brain Stimulation (DBS). The Professorial Unit at The Melbourne Clinic is involved in studying two novel treatments - a medication called N-acetyl cysteine (NAC), and Virtual Reality Exposure Therapy (VR) for OCD.