What causes OCD?

Obsessive-compulsive disorder (OCD) affects 2 to 3% of the population. OCD is characterised by the appearance, on average around the age of 20 (around the age of 14 in 25% of cases), of ideas or images that are repeated, persistent, unwanted and often anxiety-provoking. These obsessions are often accompanied by repetitive behaviours designed to neutralise the anxiety and anguish resulting from the obsessions, known as compulsions. OCD is considered to be a disease of behaviour, thought and emotion. Around a third of patients with OCD have had, or still have, TIC.
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The causes of obsessive-compulsive disorder

The causes of brain dysfunction leading to obsessive-compulsive disorder (OCD) are still unknown. There is a genetic predisposition, i.e. an increased risk of developing the disease for 1st-degree relatives of a patient. This risk is estimated at 8%, compared with 2% in the general population, but we still do not know all the genetic variants associated with these disorders. The hypothesis of an autoimmune mechanism in certain early forms of the disease (inflammatory reaction directed against a component of the brain) has been put forward but has not yet been proven.