The Surprising Cause Of OCD

We all obsess on occasion, but for people with obsessive compulsive disorder, obsessing can take control of their lives. Why can some people obsess occasionally while others develop OCD? Furthermore, what causes OCD? Researchers may have found the surprising reason. People who suffer from OCD are tired of hearing that it's all in their heads, but it turns out this might be true, but not in the way you think. According to new research from the University of Würzburg published in the journal Molecular Psychiatry, an overactive molecular-signal pathway in the amygdala region of the brain may be responsible for OCD.

The amygdala, the part of the brain responsible for keeping us safe, tells us when we are in danger, and propels us into fight or flight mode. People who experience OCD (around 2 percent of the population) are plagued by persistent intrusive thoughts which they try to compensate for with repetitive, ritualized behavior. The disorder can interfere with work, relationships, and day-to-day life. OCD is often treated with a range of anti-depressants, but, according to the study, the medication is not tailored specifically for OCD prompting researchers to search for more targeted therapies that have fewer side effects.

Because medication only treats some OCD symptoms, and does not treat the underlying cause, Professor Kai Schuh from the Institute of Physiology at the Julius-Maximilians-Universität (JMU) Würzburg (Germany) and his team, in collaboration with the JMU's departments of psychiatry, and neurology, explored the underlying causes of OCD in hopes of identifying a specific trigger for the disorder.

It turns out that a missing protein in the brain could be responsible for some OCD behaviors, including obsessive hand washing.

"We were able to show in mouse models that the absence of the protein SPRED2 alone can trigger excessive grooming behavior," Schuh told Science Daily.

Schuh called the finding "crucial" because it is the first time a clear trigger has been identified for OCD. According to Science Daily, the protein SPRED2 is found in particularly high concentrations in regions of the brain, namely in the basal ganglia and the amygdala. Normally, the protein inhibits an important signal pathway of the cell, the so-called Ras/ERK-MAP kinase cascade. When it is missing, this signal pathway is more active than usual, which can trigger OCD.

Biologist Dr. Melanie Ullrich told Science Daily, "It is primarily the brain-specific initiator of the signal pathway, the receptor tyrosine kinase TrkB, that is excessively active and causes the overshooting reaction of the downstream components."

When researches administered an inhibitor to the mice in the study, their OCD symptoms improved. The discovery opens up new options for OCD treatment, including medications that are already on the market, researchers claimed.

On Brain Physics, Susan Swedo, Head of the Section on Behavioral Pediatrics, Child Psychiatry Branch of the National Institute of Mental Health (NIMH), and author of It's Not All In Your Head, said: "For people who suspect that they have OCD, the most important thing is to find a doctor who has some experience treating the disorder because some kinds of psychotherapy appear to have little impact."

While the majority of OCD behavior begins in childhood, most of those who experience symptoms wait more than 10 years before seeking treatment. Swedo assures that the disorder is real, and debilitating, and exposure to stress can make it worse.

"We have good firm scientific evidence these disorders are real," she said on Brain Physics. "Brain scans, for example, have shown a marked difference in brain activity patterns between people with no mental illness, other conditions and OCD."

Because the German study successfully treated OCD in mice with existing medications, the path to recovery could be on the horizon. If you think you have OCD, talk to your doctor about treatment options because while science proves the cause may lie in your brain, it's not all in your head.