An international team of scientists from the Broad Institute of MIT and Harvard and other institutions has found evidence of four genes that may be linked to obsessive compulsive disorder (OCD). In the article, which has been published in the journal Nature Communications , the experts describe their approach to isolating the genes linked to this anxiety disorder and what they found as a result.
Charles Dickens or Marcel Proust suffered from it and it is believed that Nikola Tesla and Charles Darwin, too. Obsessive-compulsive disorder is a psychiatric condition characterized by recurring and persistent thoughts, which cause fear, restlessness, apprehension or worry, and repetitive behaviors called compulsions, to mitigate said anxiety.
Thus, people who suffer from it tend to repeat compulsive behaviors because their brain tells them that something has not been solved properly and they experience the urge to solve a problem, such as washing their hands again.
There is no cure for the disease , although recent studies have shown that, in some cases, the use of medications that increase serotonin levels can help. Previous research has also shown that OCD is likely to be a hereditary condition, and the scientists in the current study focused on this by finding the genes likely to cause the disorder.
The study consisted of first obtaining genetic samples from 592 people diagnosed with OCD and 560 healthy people, as a control group. Genetic samples from dogs suffering from the canine form of this disorder were also included.
With all these samples, the researchers focused on 600 specific genes possibly related to OCD and, in some cases, autism, as many people with autism spectrum disorder have repetitive behaviors. After careful analysis, the scientists isolated four genes that were different in those with OCD (previously identified as important in creating brain circuits involved in building links between regions of the thalamus, striatum, and cortex).
This is a remarkable finding, as the brain’s striatum plays a key role in learning and also in transmitting messages from the thalamus to the cerebral cortex.
The researchers suggest that the 4 mutated genes could cause higher or lower levels of serotonin than normal levels, which in turn could lead to the disruption of information as interpreted by the brain, causing an abnormality in this brain circuit.
One of the genes identified (specifically the HTR2A gene) encodes a receptor for serotonin, a neurotransmitter linked to the development of certain disorders such as anxiety, stress, certain phobias and depression.
This imbalance in the serotonergic regulation of obsessive-compulsive disorder could explain the benefits obtained in 60% of patients who have been treated with antidepressants (since the drug increases the levels of serotonin in the body).
Reference: Hyun Ji Noh et al. Integrating evolutionary and regulatory information with a multispecies approach implicates genes and pathways in obsessive-compulsive disorder, Nature Communications (2017). DOI: 10.1038 / s41467-017-00831-x
