What Is Obsessive-Compulsive Disorder (OCD)?

Obsessive-compulsive disorder (OCD) is a mental health condition that causes unwanted and intrusive thoughts or images (obsessions) and repetitive behaviors and actions (compulsions). Obsessions cause significant anxiety and distress, driving people with OCD to perform repetitive, ritualistic actions for temporary relief.

Many people have the occasional obsession or compulsive behavior, but with OCD, the thoughts and behaviors are time-consuming and interfere with daily functioning. An estimated 2-3% of people in the U.S. live with OCD, which often begins in childhood, adolescence, or early adulthood.

The exact cause of OCD is unknown, but research suggests a combination of genetic, neurological, and environmental factors play a role. Treatment options for OCD usually involve psychotherapy and medication to help manage symptoms and improve your quality of life. 

Types of OCD

There are many subtypes of OCD—and symptoms can present in different ways. However, OCD mainly falls into four categories: contamination, checking, symmetry/order, and intrusive/taboo thoughts. If you have OCD, it's common to have symptoms that fall under more than one of these subtypes. 

Contamination OCD

With contamination OCD, you may have an overwhelming fear of germs or getting sick from objects or people. This may lead to excessive hand washing or avoiding touching things you think may be contaminated. It's possible to also excessively worry about ingredients in household cleaning products or frequently change clothes throughout the day.

However, fear of emotional contamination can also occur and cause you to avoid certain people, places, or situations you view as scary or dirty.

Checking OCD

Compulsive checking stems from a fear of harm or danger to yourself or other people. With this subtype of OCD, you may find yourself repeatedly checking to ensure the door is locked, appliances are turned off, and car brakes are working. Sometimes you may need constant reassurance from others that you have not done harm to others or made a mistake.

Symmetry and Order OCD

Symmetry and order obsessions derive from the need for perfectly aligned, organized, or symmetrical things. In such cases, you may strive for perfectionism and orderliness and spend a lot of time rearranging and aligning objects at home or work until they are "just right."

It may be common to also perform tasks in a specific order or tap things a certain number of times. With this type of OCD, you might have extreme anxiety or have superstitious beliefs that something terrible will happen if items are not perfectly balanced.

Intrusive/Taboo Thoughts OCD 

OCD-related intrusive and taboo thoughts are often centered around themes of violence, sex, or religion. For example, you might have graphic mental images of violence or sexual acts that are disturbing. You might notice that you're ruminating over your religious identity or sexual orientation.

Intrusive and taboo thoughts may cause guilt, shame, and anxiety and drive your to perform compulsive rituals to help calm down your feelings, such as constant praying, tapping, or saying specific phrases to "cancel out" negative thoughts. 


OCD symptoms fall into two groups: obsessions and compulsions. While some people may only have obsessions or compulsions, most people with OCD experience both. Along with obsessions and compulsions, people with OCD may avoid places, people, or situations that trigger their obsessions or compulsions.


Obsessions are persistent and often irrational thoughts, urges, or mental images that cause significant distress and anxiety. Examples of obsessions include:

  • Fear of contamination or germs
  • Worry of harm or danger to yourself or others 
  • Need for constant reassurance
  • Unwanted and unpleasant thoughts or images about sex, religion, or violence


Compulsions are repetitive behaviors or mental acts people with OCD perform to reduce anxiety, distress, or preventing a dreaded event or situation caused by their obsessions. Compulsions are not always clearly excessive or connected to what they are trying to prevent or neutralize. Examples of compulsions include:

  • Excessive cleaning or washing
  • Repeatedly checking locks, appliances, and other objects to ensure they are safe or turned off 
  • Constantly arranging and organizing objects in a specific way or according to a strict pattern 
  • Repeating phrases, counting, tapping, touching, or silently praying 


The exact cause of OCD is not fully understood, but research suggests a combination of several factors likely play a role. These factors may include:

  • Genetics: OCD often runs in families, and having a parent, sibling, or child with OCD raises your risk of experiencing symptoms. Research suggests genes play a more significant role when OCD symptoms begin in childhood.
  • Brain structure: Researchers have discovered that people with OCD have differences in their brain structure and function, particularly in the areas of the brain that regulate emotions, impulse control, and decision-making.
  • Life events: Stressful events and traumatic experiences—such as a car accident or experiencing abuse—may trigger OCD symptoms in some people. Research shows this may be more common in women.
  • Comorbid (or, co-occurring) conditions: People with pre-existing anxiety or mood disorders, and those with a history of certain infections (e.g., streptococcal infection), are at an increased risk of OCD.


The first step in getting an OCD diagnosis is visiting a healthcare provider who has the knowledge and skills to make an OCD diagnosis, such as a psychiatrist, psychologist, or licensed mental health professional.

No single test or procedure can definitively diagnose OCD, so healthcare providers usually use their professional judgment after learning about your symptoms and medical history. Some healthcare providers may perform a physical examination and order blood tests or other lab tests to rule out other conditions that may cause symptoms similar to OCD. 

Healthcare providers use the OCD diagnostic criteria listed in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) to make a diagnosis. Diagnostic criteria for OCD include:

  • The presence of obsessions, compulsions, or both 
  • Obsessions and compulsions that last for more than one hour per day and cause significant distress and/or interfere with daily activities
  • Symptoms that are not due to substance use, prescription medications, or an underlying health condition

To learn about your symptoms, how often they occur, how intense they can be, and what triggers them, your provider will likely conduct a structured clinical interview. They may use a standardized rating scale, such as the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), to measure the severity of your OCD symptoms and how they interfere with your day-to-day life. Your provider will also ask about your medical and psychiatric history, family history, and substance use (e.g., drugs and alcohol). 


The goal of OCD treatment is to help you learn new, healthy ways to respond to your thoughts to eliminate and reduce your symptoms and their effect on your life. While there is no cure for OCD, there are effective treatments—and research shows that over 50% of people with OCD who follow their treatment plan achieve remission (or, a period where you experience little to no symptoms). Treatment for OCD usually involves a combination of psychotherapy and medication. 


Psychotherapy, particularly cognitive-behavioral therapy (CBT), is a first-line treatment for OCD. Exposure and response prevention (ERP) is a specific type of CBT that involves gradual exposure to your fears or obsessions and learning how to replace compulsive behaviors with healthy coping strategies that can help you reduce anxiety.


Your provider may choose to prescribe you medication, which can either be used alone or in combination with psychotherapy. People with OCD who take prescription medications experience a 40-60% reduction in symptoms.

Selective serotonin reuptake inhibitors (SSRIs) are the most effective medication for OCD. SSRIs are antidepressants, but they also help reduce OCD symptoms by boosting serotonin (a hormone that helps your brain regulate mood, sleep, and other body functions) levels in the brain. 

How to Prevent OCD

There is no known way to prevent OCD from developing, but early diagnosis and treatment can help improve symptoms and prevent them from worsening over time. OCD is a complex condition, and following your treatment plan and seeking continued support from mental health professionals can help reduce the frequency of triggers and symptoms and improve your chances of achieving remission. 

Stressful life events and situations can trigger OCD symptoms, so finding healthy ways to manage stress—whether through exercise, meditation, or OCD support groups—may also be helpful. Some people find that mindfulness techniques can help you see your obsessive thoughts more objectively and help you let go of harmful thinking.

Comorbid Conditions

About 90% of people with OCD also have at least one other mental health condition. When a person has one or more mental health diagnoses simultaneously, they are known as comorbid conditions or comorbidities. Common OCD comorbidities include:

  • Anxiety disorders: Ongoing and excessive worry and fears about various things (e.g., social anxiety or generalized anxiety disorder). 
  • Major depressive disorder: Persistent sadness, hopelessness, and loss of interest in activities. 
  • Eating disorders: Unhealthy patterns of eating and a preoccupation with body image (e.g., anorexia nervosa or bulimia).
  • Bipolar disorders: Extreme changes in mood, behavior, and energy levels. 
  • Substance use disorder: Excessive use of substances (e.g., drugs or alcohol).

Living With OCD

Living with OCD can be challenging—between the overwhelming, obsessive thoughts and time-consuming compulsions, the disorder's effect on your life can be devastating. Fortunately, with effective treatments and healthy coping strategies, many people with OCD live fulfilling and productive lives. 

If you're newly diagnosed with OCD or know someone with the condition, learning as much as possible about the condition can help you understand why obsessions and compulsions occur and extend grace and patience during times of struggle. Many people with OCD find community and camaraderie by joining OCD support groups. Connecting with others who understand what you're going through can be helpful, and many groups offer practical advice and coping strategies. 

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26 Sources
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  1. International OCD Foundation. About OCD.

  2. International OCD Foundation. Who gets OCD?.

  3. Nazeer A, Latif F, Mondal A, Azeem MW, Greydanus DE. Obsessive-compulsive disorder in children and adolescents: epidemiology, diagnosis and management. Transl Pediatr. 2020;9(Suppl 1):S76-S93. doi:10.21037/tp.2019.10.02

  4. Ramezani Z, Rahimi C, Mohammadi N. Predicting obsessive compulsive disorder subtypes using cognitive factors. Iran J Psychiatry. 2016;11(2):75-81.

  5. International OCD Foundation. OCD and contamination.

  6. International OCD Foundation. Emotional contamination.

  7. Strauss AY, Fradkin I, McNally RJ, Linkovski O, Anholt GE, Huppert JD. Why check? A meta-analysis of checking in obsessive-compulsive disorder: threat vs. distrust of senses. Clin Psychol Rev. 2020;75:101807. doi:10.1016/j.cpr.2019.101807

  8. Lochner C, McGregor N, Hemmings S, et al. Symmetry symptoms in obsessive-compulsive disorder: clinical and genetic correlates. Braz J Psychiatry. 2016;38(1):17-23. doi:10.1590/1516-4446-2014-1619

  9. BeyondOCD. Extreme need for symmetry or exactness.

  10. Schwartzman CM, Boisseau CL, Sibrava NJ, Mancebo MC, Eisen JL, Rasmussen SA. Symptom subtype and quality of life in obsessive-compulsive disorder. Psychiatry Res. 2017;249:307-310. doi:10.1016/j.psychres.2017.01.025

  11. UpToDate. Obsessive-compulsive disorder in adults: Epidemiology, pathogenesis, clinical manifestations, course, and diagnosis.

  12. Wheaton MG, Gershkovich M, Gallagher T, Foa EB, Simpson HB. Behavioral avoidance predicts treatment outcome with exposure and response prevention for obsessive-compulsive disorder. Depress Anxiety. 2018;35(3):256-263. doi:10.1002/da.22720

  13. MedlinePlus. Obsessive-compulsive disorder.

  14. National Institute of Mental Health. Obsessive-compulsive disorder.

  15. Mahjani B, Bey K, Boberg J, Burton C. Genetics of obsessive-compulsive disorder. Psychol Med. 2021;51(13):2247-2259. doi:10.1017/S0033291721001744

  16. Parmar A, Sarkar S. Neuroimaging studies in obsessive compulsive disorder: a narrative review. Indian J Psychol Med. 2016;38(5):386-394. doi:10.4103/0253-7176.191395

  17. Murayama K, Nakao T, Ohno A, et al. Impacts of stressful life events and traumatic experiences on onset of obsessive-compulsive disorder. Front Psychiatry. 2020;11:561266. doi:10.3389/fpsyt.2020.561266

  18. Goodwin GM. The overlap between anxiety, depression, and obsessive-compulsive disorder. Dialogues Clin Neurosci. 2015;17(3):249-260. doi:10.31887/DCNS.2015.17.3/ggoodwin

  19. Vogel L. Growing consensus on link between strep and obsessive-compulsive disorder. CMAJ. 2018;190(3):E86-E87. doi:10.1503/cmaj.109-5545

  20. BeyondOCD. Clinical definition of OCD.

  21. Rapp AM, Bergman RL, Piacentini J, McGuire JF. Evidence-based assessment of obsessive-compulsive disorder. J Cent Nerv Syst Dis. 2016;8:13-29. doi:10.4137/JCNSD.S38359

  22. Sharma E, Math SB. Course and outcome of obsessive-compulsive disorder. Indian J Psychiatry. 2019;61(Suppl 1):S43-S50. doi:10.4103/psychiatry.IndianJPsychiatry_521_18

  23. Anxiety and Depression Association of America. Treatments for OCD.

  24. International OCD Foundation. Medications for OCD

  25. International OCD Foundation. Mindfulness and cognitive behavioral therapy for OCD.

  26. BeyondOCD. Disorders that may co-exist with OCD.

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