Our findings

These obsessions and compulsions can often be extremely time-consuming, and may lead an individual to avoid certain people, places or objects.  

As a result, they can cause significant personal distress, and interfere with work, social or daily functioning. Adverse long-term outcomes can include anxiety or depression, social isolation and increased risk of substance abuse.

Key findings

3% of Australians will experience OCD

Typically develops around 19 years of age

Closely linked with depression and anxiety


It is estimated that around 3% of Australians will experience OCD at some point in their lifetime. While OCD can develop gradually at any stage during the lifespan, the average onset is around 19 years of age and is rare after 35 years of age.

In children, OCD is more common amongst males. However, females are affected at slightly higher rates in adulthood. People with OCD can experience other mental health conditions, such as depression or anxiety.  

Possible causes

OCD is a complex disorder which can be caused by genetic, biological and/or environmental risk factors. Individuals with a family history of OCD are approximately twice as likely to develop the disorder. This suggests a genetic contribution.

However, other research indicates that OCD may develop from watching and learning the behaviours of others.

Biological risk factors may include an imbalance in the neurotransmitter, serotonin, or changes in brain function. Stressful life events also have the potential to trigger OCD symptoms. 


Common symptoms include repetitive thoughts or concerns which are intrusive or unwanted. Often, individuals may attempt to suppress or ignore these thoughts. They may also display repetitive behaviours such as handwashing, counting or ordering, which must be carried out according to strict rules.

The content of obsessions and compulsions is different for each individual. However, common themes may include cleaning, ordering/symmetry, fear of harm, or aggressive or sexual thoughts. 

Treatment options

Evidence shows that cognitive-behavioural therapy (CBT) with exposure and response prevention (ERP) can be immensely helpful for people with OCD.

Medications, such as selective serotonin reuptake inhibitors (SSRIS) are also effective for more severe symptoms.

Explore our other research themes

Contact the Centre for Mental Health

There are many ways to engage with us. Whether you’re a PhD student, media, or an organisation looking to form a partnership, contact the Centre on +61 3 9214 3865 or via cmh@swinburne.edu.au.

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