Study Points to Fast-Acting Drug for OCD

Posted on July 19, 2016

A single chemical receptor in the brain is responsible for a range of symptoms in mice that are reminiscent of obsessive-compulsive disorder (OCD), according to a Duke University study that appears online in the journal Biological Psychiatry.

The findings provide a new mechanistic understanding of OCD and other psychiatric disorders and suggest that they are highly amenable to treatment using a class of drugs that has already been investigated in clinical trials.

OCD, which affects 3.3 million people in the United States, is an anxiety disorder that is characterized by intrusive, obsessivethoughts and repeated compulsive behaviors that collectively interfere with a person’s ability to function in daily life.

In 2007, Duke researchers (led by Guoping Feng, who is now at the Massachusetts Institute of Technology) created a new mouse model of OCD by deleting a gene that codes for Sapap3, a protein that helps organize the connections between neurons so that the cells can communicate.

Similar to the way some people with OCD wash their hands excessively, the Sapap3-lacking mouse grooms itself excessively and shows signs of anxiety. Although researchers praised the new model for its remarkable similarity to a human psychiatric disorder, and have begun using it to study OCD, questions remain about how the loss of the Sapap3 gene leads to the grooming behaviors.

In the new study, Calakos’s team found that overactivity of a single type of receptor for neurotransmitters -- mGluR5, found in a brain region involved in compulsive behaviors -- was the major driver for the abnormal behaviors. When researchers gave Sapap3-lacking mice a chemical that blocks mGluR5, the grooming and anxiety behaviors abated.

“The reversibility of the symptoms was immediate -- on a minute time frame,” Calakos said. In contrast, the original study describing Sapap3-lacking mice found that antidepressants could help treat symptoms but on the time scale of weeks, as is typical with these drugs in patients.

The immediate effects seen in the new study were also surprising, given that the brains of these mice appear developmentally immature and neurodevelopmental diseases are not typically thought of as being easily reversible, Calakos said.


Category(s):Obsessions & Compulsions (OCD)

Source material from Duke University