Around 2.2 million people in the US are affected by obsessive-compulsive disorder. It is unknown as to what causes the disorder, but researchers from Johns Hopkins University School of Medicine in Baltimore, MD, say they have uncovered a genetic marker that may provide clues.

Obsessive-compulsive disorder (OCD) is a psychiatric condition. It is characterized by intrusive and unwanted anxiety-causing thoughts that trigger repetitive and ritualistic behaviors in an attempt to overcome such thoughts.

For example, a person may have a constant, irrational worry about germs or contamination; therefore they feel the need to repeatedly wash their hands – sometimes for hours at a time.

Mild forms of OCD can add up to an hour a day to a person’s routine, while more severe forms of the condition can disable a person so much that they are unable to leave their home.

There is no cure for OCD, but symptoms can be managed through behavioral therapy and antidepressants, such as selective serotonin reuptake inhibitors (SSRIs). However, it is estimated that such treatment only works in 60-70% of cases.

But the Johns Hopkins researchers say their latest findings, recently published in the journal Molecular Psychiatry, may lead to a better understanding of the condition and new therapies.