What Causes OCD?
OCD is an anxiety disorder that has a neurobiological basis. Using neuroimaging technologies in which pictures of the brain and its functioning are taken, scientists have shown that functioning in some areas of the brain is different in individuals who have OCD compared to those who don’t.
Research shows that the disorder may involve communication errors that take place between the orbitofrontal cortex (front part of the brain), the striatum, and the thalamus (deeper parts of the brain). Abnormalities in the serotonin and other neurotransmitter systems—chemicals that send messages between brain cells – also are involved in the disorder.
A study funded by the National Institutes of Health examined DNA, and the results suggest that OCD and certain related psychiatric disorders may be associated with an uncommon mutation of the human serotonin transporter gene (hSERT). People with severe OCD symptoms may have a second variation in the same gene. Other research points to a possible genetic component—about 25% of OCD sufferers have an immediate family member with the disorder.
It would be easy to blame OCD on factors such as stress or parenting. But no research has ever shown that stress or the way a person interacted with his or her parents during childhood causes OCD. Stress can, however, be a factor in triggering OCD in someone who is predisposed to it, and OCD symptoms can worsen in times of severe stress.
Some people exhibit symptoms of OCD after a brain injury, which also suggests a connection between brain function impairment and OCD. And some children begin to exhibit symptoms after a severe infection such as strep throat. However, studies suggest the infection doesn’t actually cause OCD, but triggers symptoms in children who are genetically predisposed to the disorder.
Everyone’s brain churns out random and strange thoughts. Most people simply dismiss them and move on, but they get “stuck” in the brains of people with OCD. These random thoughts are like the brain’s junk mail. Most people have a spam filter and can simply ignore junk mail that comes their way. But having OCD is like having a spam filter that has stopped working—the junk mail just keeps coming and you cannot make it stop. Soon, the junk mail seriously outnumbers the wanted mail, and you become overwhelmed.