ExpertsTrusted Source do not know what causes OCD, but there are various theories. Genetic, neurological, behavioral, cognitive, and environmental factors may all contribute.
OCD appears to run in families, suggesting a possible genetic link, which experts are investigating.
Imaging studiesTrusted Source have suggested that the brains of people with OCD function with characteristic differences. Genes that affect how the brain responds to the neurotransmitters dopamine and serotonin, for example, may play a role in causing the disorder.
Sometimes, symptoms of OCD appear in children after an infection, such as:
- group A streptococcal infections, including strep throat
- Lyme disease
- the H1N1 flu virus
Clinicians sometimes call this occurrence of OCD symptoms pediatric acute-onset neuropsychiatric syndrome (PANS).
In a child with PANS, the symptoms start suddenly and reach full intensity within 24–72 hours. They may then disappear but return at a later date.
One theory suggests that a person with OCD learns to avoid fear associated with certain situations or objects by performing rituals to reduce the perceived risk.
The initial fear may begin around a period of intense stress, such as a traumatic event or significant loss.
Once the person associates an object or circumstance with this feeling of fear, they begin to avoid that object or situation in a way that comes to characterize OCD.
This may be more common among people with a genetic predisposition for the disorder.
Another theory is that OCD starts when people misinterpret their own thoughts.
Most people have unwelcome or intrusive thoughts at times, but for people with OCD, the importance of these thoughts becomes more intense or extreme.
Take the example of a person caring for an infant while under intense pressure and having intrusive thoughts of accidentally harming the baby.
A person might usually disregard these thoughts, but if the thoughts persist, they may take on unwarranted significance.
A person with OCD may become convinced that the action in the thought is likely to happen. In response, they take excessive, continual action to prevent the threat or danger.
Stressful life events may trigger OCD in people with a predisposition, genetic or otherwise.
Many people have reported that the symptoms appeared within 6 months of events such as:
- complications during pregnancy or delivery
- a severe conflict
- a serious illness
- a traumatic brain injury
Also, OCD may occur alongside post-traumatic stress disorder, or PTSD.
Doctors look for specific criteria when diagnosing OCD, including:
- the presence of obsessions, compulsions, or both
- obsessions and compulsions that are time-consuming or cause significant distress or impairment in social, occupational, or other important settings
- OCD symptoms that do not result from the use of a substance or medication
- OCD symptoms that cannot be better explained by another health issue
Many other disordersTrusted Source, such as depression and anxiety, have similar features to OCD, and they can also occur alongside OCD.
There are effective treatments for OCD. The right approach depends on the person’s set of symptoms and the extent that they affec the person’s life and well-being. Some effective optionsTrusted Source include:
Cognitive behavioral therapy
This type of psychotherapy, sometimes called CBT, can help a person change the way that they think, feel, and behave.
It may involve two different treatmentsTrusted Source: exposure and response prevention (ERP) and cognitive therapy.
- Exposure: This exposes the person to situations and objects that trigger fear and anxiety. Over time, through a process called habituation, repeated exposure leads to a decrease or disappearance of the anxiety.
- Response: This teaches the person to resist performing compulsive behaviors.
Cognitive therapy starts by encouraging the person to identify and reevaluate their beliefs about the consequences of engaging or refraining from engaging in compulsive behavior.
Next, the therapist encourages the person to:
- examine the evidence that supports and does not support the obsession
- identify cognitive distortions relating to the obsession
- develop a less threatening alternative response to the intrusive thought, image, or idea
A number of drugsTrusted Source can help treat OCD, including selective serotonin reuptake inhibitors (SSRIs), which are a type of antidepressant.
Some examples include:
- escitalopram (Lexapro)
- fluvoxamine (Luvox)
- paroxetine (Paxil)
- fluoxetine (Prozac)
- sertraline (Zoloft)
A doctor may prescribe a higher dosage to treat OCD, compared with depression. Still, a person may not notice results for up to 3 monthsTrusted Source.
About half of all peopleTrusted Source with OCD do not respond to SSRI treatment alone, and doctors may also prescribe antipsychotic medications.
Also, in 2010, some researchers noted that the tuberculosis drug D-cycloserine (Seromycin) alongside CBT may help treat OCD. It may also helpTrusted Source people with social anxiety.
If a person with mild OCD does not receive treatment, the symptoms may still improve. However, without treatment, symptoms of moderate or severe OCD do not improve and may worsen.
Treatment can be effective, but it is an ongoing process. In some people, OCD symptoms reappear later in life.
Anyone who may be experiencing OCD should receive professional care and guidance.