Found: Genetic Marker for Obsessive Compulsive Disorder

Researchers at Johns Hopkins University School of Medicine and colleagues have identified a genetic marker for obsessive compulsive disorder or OCD. If confirmed, the research could lead to development of drugs that could reduce the severity of this crippling, yet least understood mental disorder.

Obsessive-compulsive disorder is a type of anxiety disorder and affects around 2.2 million American adults. The mental illness can interfere with daily activities and cause severe distress. Media often shows OCD as some 'quirky habit' such as counting things or being careful about sequences or patterns. Cameron Diaz, for example, is rumored to use elbows to open doorknobs to avoid touching the knobs.

However, the disorder is a lot more complex. Obsession in the term OCD refers to frequent upsetting thoughts such as imagining harming or killing loved ones. Compulsions are a set of rituals or behaviors that the person performs to control panic attacks. Common examples of compulsive behaviors include unnecessary unlocking and locking doors or washing hands for a specific number of times.

"If this finding is confirmed, it could be useful," said study leader Gerald Nestadt, M.D., a professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine, according to a news release. "We might ultimately be able to identify new drugs that could help people with this often disabling disorder, one for which current medications work only 60 to 70 percent of the time."

The team conducted a type of research called genome-wide association study. . GWAS studies examine the link between genes and specific traits (mostly used to study human disease).  In this study, researchers scanned the genome of 1,400 people with OCD and 1,000 close relatives of people with the condition. Researchers found that a gene called protein tyrosine phosphokinase (PTPRD) had links with OCD.

Research conducted on animals has shown that the gene is involved in learning and memory. Also, the PTPRD gene is linked to Attention Deficit Hyperactivity Disorder, another mental disorder that shares some of the symptoms of OCD, Nestadt said. Additionally, the gene along with another gene family, SLITRK has been implicated in OCD in animals.

"OCD research has lagged behind other psychiatric disorders in terms of genetics," Nestadt said in a news release. "We hope this interesting finding brings us closer to making better sense of it-and helps us find ways to treat it."

The study is published in the journal Molecular Psychiatry.