This study could explain why people with OCD can't overcome their urges

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People with obsessive-compulsive disorder (OCD) struggle to overcome their repetitious urges due to an inability to learn what kinds of stimuli are actually safe, new research suggests.

OCD is a disorder where people feel compelled to repeatedly perform certain tasks or think particular thoughts. These insistent routines are called 'rituals', and scientists think the behaviours persist because those with OCD struggle to learn when situations aren't threatening.

"Our study suggests that something is going wrong in the brains of people with OCD when they are learning what is safe, and this in turn affects how they perceive threats under updated circumstances," says neuroscientist Annemieke Apergis-Schoute from the University of Cambridge in the UK.

Apergis-Schoute and her team conducted a learning experiment where they compared the brain activity and anxiety responses of OCD patients with measurements taken from people without the condition.

OCD is estimated to affect around 1 percent of the adult population in the US, with the disorder compelling people to do things like repeatedly wash their hands, or check that doors are locked and appliances are switched off.

The findings are reported in PNAS