Four Brain Genes Help Explain Obsessive Compulsive Disorder

Scientists have linked four main genes to obsessivecompulsive disorder (OCD).  These genes all play a role in the brain and provide evidence that OCD may be genetic.  Individuals with obsessive compulsive disorder suffer from repetitive thoughts and extreme anxiety that leads to behavior beyond the norm.  Hyun Ji Noh and her colleagues at the Broad Institute of MIT and Harvard studied over 600 genes from 592 individuals who suffer from OCD and from 560 individuals who do not suffer from OCD.  From these genes, 222 of them were linked to “compulsive grooming in mice, and 196 had been linked to autism in people”.  Autism is a secondary condition that can result in repetitive behaviors, similar to OCD.  Also, this research team discovered 56 genes in dogs that lead to compulsive disorders as well.

Individuals with obsessive compulsive disorder (OCD) may suffer from repetitive rituals such as flicking the light a certain number of times before entering or exiting a room.

The four genes linked to obsessive compulsive disorder link the striatum, thalamus, and cortex regions, all together forming a brain circuit.  The striatum is responsible for the learning aspects of an individual and relays that new information to the cortex (where decisions are made) via the thalamus.  The four genes linked to this disorder are said to inhibit or disrupt the brain circuit: striatum, thalamus, and cortex.  Disruptions to this circuit make it harder for the individual to distinguish between safe and risky situations.  One of these genes is thought to deregulate serotonin; which regulates anxiety, happiness, and mood.  The evidence of this is shown when patients suffering from this order take SSRI, a drug which regulates serotonin.  New findings indicate further a genetic component to OCD.  It states that if you have first-degree relative (parent, sibling, and or child) with this condition you are four times more likely to have the condition as well. 

There are some treatments out there for obsessive compulsive disorder.  One gene identified through analysis, the HTR2A gene, is observed to be responsible for serotonin signaling.  People with OCD may have problems with serotonin signaling due to a lack of or a mutation on this gene.  The findings in this article provide evidence to why individuals who suffer from obsessive compulsive disorder take SSRI antidepressants that increase the amount of serotonin in the brain, helping to reverse the effects of this disorder.