Researchers have found new clues on the potential cause of OCD. 

Experts at QIMR Berghofer say they are a step closer to solving what causes obsessive-compulsive disorder (OCD), after discovering changes in how distinct brain regions communicate. 

The finding could guide the development of more targeted and effective treatments for this debilitating condition impacting thousands of Australians.

About two per cent of Australians are affected by OCD, which is characterised by distressing obsessive thoughts and compulsive behaviours, often to do with cleaning, counting or checking. The condition is linked to depression and anxiety disorders and is associated with high rates of suicide.

In their new study, the researchers confirmed that the disorder likely emerges from a complex imbalance affecting particular signalling pathways deep within the brain.

Associate Professor Luca Cocchi says the information will be instrumental to QIMR Berghofer’s efforts to develop innovative brain stimulation treatments for OCD - a condition with limited treatment options and no known cure.

“This study offers some important clues as to how we might research and develop treatments that better target OCD and its symptoms,” A/Prof Cocchi says.

“Current drug interventions lack specificity and only meaningfully reduce symptoms in a portion of individuals with OCD. That means a lot of people are not getting the help they need for symptoms that can be severe and significantly diminish quality of life. We urgently need safe and more effective therapeutic interventions.”

The study, published in the prestigious journal Brain, is the first to emerge from a QIMR Berghofer trial of a potential brain stimulation therapy for OCD. Before administering the treatment, researchers used magnetic resonance imaging (MRI) to examine the brains of participants against a cohort of people without the condition.

Lead researcher Dr Sebastien Naze said the participants with OCD were shown to have an imbalance affecting distinct pathways and regions of the brain, which are linked to emotion regulation and reward.

“While more research is needed, this imbalance is believed to be a main driver and potential cause of OCD symptoms,” Dr Naze said.

“We aren’t the first researchers to find it, but our study offers important validation and new information on the specific communication between brain regions involved in this imbalance. “This gives us some important clues about what’s causing the disease, and how these brain changes could be corrected to reduce OCD symptoms.”

The researchers will use the findings to inform clinical trials of a range of non-invasive and invasive brain stimulation therapies for OCD in 2023.

They are currently analysing the results of their recently-completed trial of transcranial magnetic stimulation, ahead of separate trials examining the effects of deep brain stimulation and ultrasound-based procedures.