Obsessive-compulsive disorder, an anxiety disorder estimated to affect about one in 100 adults or up to 3 million adults in the United States, is characterized by intrusive thoughts that cause worry, fear and a perceived need to do rituals and engage in certain thoughts. People with OCD may excessively wash their hands, do repetitive tasks and have aversion to certain numbers, behaviors that may cause distress and affect their way of life.  

Current treatments for OCD include behavioral therapy and selective serotonin reuptake inhibitors (SSRI), but these do not work at all time and only address the symptoms of the disease. In what could potentially lead to the development of a drug treatment for OCD, researchers have identified a genetic marker that may be linked with the development of OCD.

In the study published in the journal Molecular Psychiatry on May 13, researchers scanned the genomes of 1,406 individuals with OCD and those of more than 1,000 parents whose children have the disorder to look for a certain genetic marker associated with OCD.

Study author Gerald Nestadt, from the Johns Hopkins University School of Medicine, and his colleagues identified a genetic marker found near the protein tyrosine phosphokinase (PTPRD) gene as it was more prevalent among participants with OCD than those in the control group. The PTPRD gene is notably associated with learning and memory, which are influenced by OCD. It is also linked with attention-deficit hyperactivity disorder (ADHD), a condition that shares some symptoms with OCD.

The researchers, however, said that although they have found a genetic marker, they still need to find the exact variant linked with OCD to determine the genetic cause of the disorder. Nestadt explained that a genetic marker is not often the cause of abnormality, albeit it tells that something near it may be the object of interest.

"The idea is that if we know what chemical or protein is affected in the condition," Nestadt said, "then we can work out what problem is in the brain that causes the condition and the next step is to find a pharmaceutical that changes that or affects that so as to improve the condition."