Obsessive-compulsive disorder, or OCD, is a mental disorder characterized by recurrent, persistent thoughts and images (obsessions) and ritualistic behaviors (compulsions) that interfere with a person's daily life and relationships, according to the "Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition" (DSM-5).
People with OCD often realize their compulsive behavior is irrational, but they may feel that they do not have the ability to stop engaging in it, since doing so would only increase their level of anxiety.
The International OCD Foundation estimates that about 1 in 100 adults, and 1 in 200 children in the United States has OCD. The condition often appears first during the childhood or teen years, and it tends to occur in men and women in roughly equal numbers.
Symptoms of OCD
OCD can manifest in many ways, but in general, a person with this disorder has obsessions that result in compulsive behaviors.
"Obsessions are automatic and obtrusive. They come on you whether you like it or not," said Jeff Szymanski, a clinical psychologist and executive director of the International OCD Foundation, a nonprofit organization in Boston. "Compulsions are deliberate, purposeful behaviors that someone does in response to the obsession and anxiety [of OCD] in an effort to make the obsessions and anxiety go away."
This is why compulsions often have some connection to the obsession that triggers them. A child who obsesses about germs or contamination, for example, might compulsively wash his or her hands. Other common obsessions and compulsions include the constant need to "check" things, such as whether the front door is locked or the oven is turned off, and an obsession with counting or arranging things in a particular order, according to the International OCD Foundation.
While OCD symptoms show up differently in each individual, those with the disorder have at least one thing in common: Their obsessive-compulsive tendencies get in the way of everyday life. This is what separates OCD from day-to-day anxiety and habits that are deemed "normal."
A small amount of obsessive thinking or compulsive behavior is not necessarily a symptom of OCD. Anxiety is a normal response to stress that serves a valuable purpose, Szymanski told Live Science. The ability to foresee, and then worry about, possible dangers allows humans to take precautionary measures and survive difficult situations. But those with OCD may worry and compulsively perform "precautionary" behaviors even after they have determined that no danger exists.
Causes of OCD
In most cases, there isn't one particular cause of OCD. Many factors likely combine to create the disorder. One of those factors is genetics, as OCD often runs in families.
The disorder is also known to coincide with abnormalities in certain brain processes. When exposed to threatening or frustrating situations, most people with OCD experience hyperactivity in the parts of the brain regulating external stimuli. These brain regions include the amygdala, which evaluates and processes danger, and the orbital frontal cortex, which performs cognitive processing and decision-making functions.
The neurotransmitter serotonin may also play a part in OCD. (Neurotransmitters are chemicals that relay messages within the brain.) Medication that modifies serotonin levels can reduce OCD symptoms (see Treatments, below).
A lesser-known cause of OCD is bacterial infection in children. Known as Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS), this form of OCD only affects children and is associated with sudden onset of extreme OCD symptoms, including:
- anxiety (including acute separation anxiety and irrational fears)
- irritability or aggression
- behavioral (developmental) regression
- sudden deterioration in school performance
- sensory or motor abnormalities (particularly trouble with handwriting)
- physical signs and symptoms
While this sudden onset of OCD usually occurs after a strep infection, it can also come after other bacterial infections, according to the International OCD Foundation.
Diagnosis of OCD
Not all perfectionist or repetitive behaviors are symptomatic of OCD. Washing your hands two times after exiting the subway or triple-checking that the front door is locked before going to bed do not mean that you have OCD, according to Szymanski.
"In popular culture, OCD has come to mean 'someone who likes things a particular way,' but it's important to look at the other part of the definition for this disorder, that you're having these obsessions and doing these behaviors, and it's really time-consuming. It's really distressing, and it's getting in the way of you functioning in the world in the way that you would like to," Szymanski said.
It is only when the behaviors become so severe and time-consuming that they interfere with that person's normal daily life that a health care expert might make a diagnosis of OCD. And only a qualified physician or mental-health specialist can make such a diagnosis accurately.
The condition is often present with other mental-health disorders, such as depression and anxiety disorders, according to the National Institutes of Health (NIH).
Treatment for OCD
There are several methods of treating OCD; most involve some kind of medication, psychotherapy or a combination of both.
Cognitive-behavioral therapy (CBT) has been shown to be effective in treating OCD by teaching individuals with the disorder to try a different approach to those situations that trigger their obsessive-compulsive behavior. One type of CBT, known as exposure and response prevention (ERP), can help people with OCD by teaching them healthy ways to respond when exposed to a feared object (dirt or dust, for example).
"In [ERP] you ask patients to purposefully make themselves anxious, and then you tell them not to do their compulsive behaviors, and [to then] see what happens," Szymanski said. "And what happens is that their anxiety levels go up. But when they allow their anxiety to just be, over time, their anxiety levels will come down."
Selective serotonin reuptake inhibitor (SSRI) antidepressants are the medications most commonly prescribed for treating OCD, according to the NIH. Anti-anxiety medication may also be prescribed.
It may take several weeks for both types of medications to begin working, according to the NIH. In addition to side effects such as headache, nausea and insomnia, antidepressants have been linked to suicidal thoughts and behaviors in some individuals. People taking antidepressants need to be monitored closely, especially when starting their treatments.
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Elizabeth is a former Live Science associate editor and current director of audience development at the Chamber of Commerce. She graduated with a bachelor of arts degree from George Washington University. Elizabeth has traveled throughout the Americas, studying political systems and indigenous cultures and teaching English to students of all ages.