Checking that the stove was turned off, or that you locked your front door, or that there are absolutely no dirty spots on your kitchen counter aren’t necessarily bad things to do. Do each of them more than a couple of times in, say, an hour, and you could have obsessive compulsive disorder (OCD). These compulsions to constantly react upon certain aspects of one’s life, aren’t unique to humans either. Dogs do them, too, and researchers have now found the genes responsible, possibly offering clues to OCD’s roots in humans.
For dogs, OCD takes form in a much cuter way. They chase their tails, stalk their shadows, lick or bite their paws, and suckle their blankets — okay, those last two aren’t so cute. Certain dog breeds have been more prone to the disorder as well, including Doberman pinschers, bull terriers, Shetland sheepdogs, and German shepherds. While analyzing the genome of these breeds, researchers at the Broad Institute at Harvard University found that four specific genes could be linked to canine OCD.
“Dogs have a simpler genetic architecture, and that simpler architecture gives us a lot of really important clues about human OCD,” Dr. Hyun Ji, a co-author of the study soon to be published in the journal Genome Biology, told NBC’s Today. The researchers became interested in how OCD forms among dogs because it develops naturally, just as it does with humans, and both can be treated with certain anti-depressive drugs, Medical News Today reported. The National Institutes of Health says that most OCD in humans starts during childhood or teenage years, and symptoms tend to fluctuate, sometimes getting better and other times worsening. It affects about 2.2 million adults in the U.S.
The researchers used several genomic techniques to pinpoint the exact ones responsible for OCD in 90 Doberman pinschers — these dogs were compared to 60 healthy Dobermans. They then sequenced the same regions in the other breeds, looking for genetic variants of the genes that didn’t appear in healthy control dogs. The four genes they found were more likely to mutate in dogs who had OCD symptoms.
“This is really exciting because psychiatric diseases tend to be very heritable, but finding genes associated with psychiatric diseases in humans has been really difficult,” Elinor Karlsson, a computational biologist at the Broad Institute, told Discovery News. “The question is: Can we use genetics to pinpoint what the brain pathways are that are going wrong in these diseases? And can we design drugs that target those pathways in ways that are much more specific than we are doing now?”
Current treatments for OCD include antidepressants and psychotherapy, but both of these still only reduce symptoms by about 60 to 80 percent in seven out of 10 people, according to the International OCD Foundation. “The right treatment is effective, but there are barriers to treatment such as stigma and misdiagnosis,” Dr. Jeff Szymanski, director of the Foundation, told Today. “I’m extremely organized, so I keep my desk neat because I want to, but a person with OCD has intense anxiety, time-consuming and embarrassing compulsive behaviors that they know are irrational and don’t want to do, but can’t stop.”