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Do you often feel like you want to wash
your hands again and again? Or do you ever have the urge to line up the items
on your desk? These all may be symptoms of obsessive-compulsive disorder (强迫症), or
OCD, which affects about 2 percent of the world's population.
Those who suffer from OCD have
difficulty finding successful treatment because doctors don't clearly
understand its causes. But now, a new study has given hope for a future cure.
For the study, which was
published in the journal Nature in
October, researchers observed humans, dogs and mice. They discovered four genes
that may be responsible for obsessive-compulsive behaviors in humans.
But why observe dogs and mice
to learn about humans?
"Dogs, it turns out, are
surprisingly similar to people," study author and geneticist Elinor
Karlsson, of the Broad Institute of MIT and Harvard University, US, told NPR.
"They're chasing their own tail or chasing shadows like normal, but
they're doing it for hours."
In the study, researchers made
a list of about 600 genes in mice, dogs and humans that they thought might
cause OCD, reported NPR. They then compared those genes in two large groups of
people – those
who don't have OCD and those who do. In the end, they identified just four
genes with mutations (突变) in the OCD group. The genes
are active in a neurological pathway (神经通路) in the
brain, which is believed to help control actions. But the mutations could block
the neurological pathway.
For example, for people without
OCD, when they finish washing their hands, a signal will come, telling them to
stop. But for people with OCD, the neurological pathway is blocked, so the
message isn't getting through. As a result, the person will continue to wash
their hands.
"OCD and anxiety are kind
of like learning disorders," Marcos Grados, an OCD researcher at Johns
Hopkins University School of Medicine, told NPR. "Often with OCD, people
have a fear of germs (细菌). You can't touch tables or door knobs (把手) and every time it's the same sensation (感觉).
You didn't learn that the last time you touched a door knob, nothing happened.
It's like touching it for the first time ever."
However, that doesn't mean
people who have these genetic mutations will always have obsessive-compulsive
behaviors, the researchers said. That's because the disorder also relies on
other things, such as one's environment.
According to reports, various
existing treatment methods have low success rates in patients. But now that we
know where OCD comes from, let's hope we will soon find an effective way to
treat it.
