Obsessive-compulsive disorder (OCD) is a chronic mental disorder. OCD involves obsessions (unwanted, intrusive thoughts) and/or compulsions (actions that someone feels the uncontrollable urge to perform repeatedly, often to try to manage the obsession).
There are many different subtypes and symptom clusters associated with OCD. Read on to learn more about the most common types of OCD, risk factors, diagnosis, and treatment.
What Is Obsessive-Compulsive Disorder?
Obsessive-compulsive disorder (OCD) is a common, long-lasting mental health condition that involves disruptive, unwanted obsessions and compulsions.
Obsessions refer to thoughts, worries, urges, preoccupations, or mental images that are persistent, disruptive, and intrusive. Common examples include:
- Fears of contamination, illness, or germs
- Extreme worries about organization, symmetry, or cleanliness
- Fear of losing or forgetting something
- Repetitive doubts or questions
- Violent or aggressive imagery or impulses
- Distressing sexual imagery or thoughts
- Religious/blasphemous thoughts
Compulsions refer to behaviors or rituals that people feel driven to repeat over and over. Usually, people participate in compulsive acts to reduce their distress about a recurring obsession. Examples may include:
- Excessive handwashing
- Repeatedly cleaning, arranging, or organizing
- Checking locks, appliances (such as the oven), or switches over and over
- Repeating certain phrases, words, or numbers
- Requesting reassurance
How Common Is Obsessive-Compulsive Disorder?
Estimates suggest that about 1.2% of adults in the U.S. meet the diagnostic criteria for OCD in a given year. OCD is more common among women than men.
Symptoms of OCD
According to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5), someone meets the diagnostic criteria for OCD if:
- They have at least one obsession or compulsion that is time-consuming, causes significant emotional distress and interferes with their daily functioning.
- They feel powerless to suppress the urge to think about their obsessions or perform their compulsion.
- Their obsessions and/or compulsions are not primarily caused by another condition, such as generalized anxiety disorder (GAD) or an eating disorder.
Some people with OCD are not aware that their obsessions are excessive. Others know that their worries or impulses are not based on reality, but they still feel unable to control them.
Different Types of OCD
There is no single official way to divide OCD into subtypes. However, many researchers agree that there are certain common themes and symptom clusters among people with OCD. Some of the most common types of OCD symptoms include checking, order/symmetry, germs/contamination, and rumination/intrusive thoughts.
One of the most common symptoms of OCD is compulsive checking. People with “checking OCD” may excessively check that their appliances are turned off, that their doors and windows are locked, or that they haven’t lost, damaged, or misplaced something important.
Checking rituals can also be related to excessive doubts and anxieties and a fear of losing control. There is often the fear of intentionally or unintentionally causing something bad to happen. For example, someone with OCD may not be able to leave the house for over an hour due to repeatedly checking the stove.
Order or Symmetry
Many people with OCD experience obsessions and compulsions related to order, symmetry, arranging, and counting. Symmetry-related compulsive rituals may involve lining things up over and over, constantly rearranging furniture to make it look “just right,” or repeatedly counting items to ensure they’re divided into equal groups.
Someone with an irrational preference for order may also become overly preoccupied with their body proportions and/or grooming habits, which can lead to disordered eating and poor self-image. Others feel compelled to perform excessive scheduling, planning, time management, and organizing rituals.
Germs or Contamination
Fear of contamination is one of the most common obsessive themes among people with OCD. People who fear germs and/or contamination may clean surfaces or wash their hands compulsively, worry excessively about ingredients in food or household products, and even avoid touching things others have touched.
Some people with OCD also experience a fear of emotional contamination. Someone who fears emotional contamination may go out of their way to avoid people, places, or topics they see as “immoral” or “dirty.”
Rumination or Intrusive Thoughts
Rumination refers to obsessive, intrusive, and unwanted thoughts around a certain theme. Rumination frequently involves taboo or forbidden topics, such as sexuality, violence, or religion.
Intrusive thoughts can take on many forms. Some people with OCD ruminate obsessively about their sexual orientation or constantly question their religious identity.
They may constantly worry that they will cheat on their partner, hurt themselves or someone else, or be sexually predatory, even in the absence of any evidence. Others experience intrusive, graphic sexual or violent mental imagery that they consider inappropriate or disturbing.
Often, rumination is related to an underlying obsession with guilt and excessive responsibility for harm. People who experience intrusive thoughts may perform compulsive rituals in an attempt to “neutralize” the perceived threat.
For example, someone who has forbidden thoughts around religion or blasphemy may pray excessively to protect themselves or others spiritually. Someone else may count, tap, or repeat certain movements or phrases because they believe it will save someone they love from harm.
Other OCD Subtypes
Researchers have identified several other possible OCD subtypes, including:
- Hoarding: Hoarding disorder is now a distinct diagnosis in the DSM-5. Hoarding refers to the compulsive, excessive collection of worthless or trivial items, often resulting in extreme clutter and disorganization. Some people with OCD hoard items that are related to an underlying obsession or fear.
- Somatic obsessions: Somatic obsessions refer to preoccupation with body parts, body functions, and/or illness. For example, someone with OCD who experiences somatic obsessions may hyperfocus on the way they breathe or swallow or monitor themselves for signs of illness.
- Pure OCD: Some researchers refer to OCD that involves only thought-based obsessions, with no behavioral or compulsive component, as “pure OCD.”
- OCD with obsessive slowness: Some people with OCD are highly prone to perfectionism. In some instances, their fear of failure may lead them to take excessive time to complete a task to ensure it’s done “just right.”
Causes and Risk Factors
There is no single known cause of OCD. Instead, researchers believe that many factors contribute to the development of OCD, including:
- Genetics: According to twin and family studies, OCD is often inherited. Having a sibling, parent, or child with OCD increases your risk of developing the disorder.
- Life events: Stressful and/or traumatic life events may trigger the onset of OCD, especially in people who are already genetically predisposed to the disorder.
- Brain structure: Studies suggest that certain differences in brain structure and function, such as hyperactivity in the orbitofrontal cortex (which helps manage emotions and decision-making), may influence the development of OCD symptoms.
- Comorbid conditions: Many people with OCD have other mental health conditions, such as attention deficit hyperactivity disorder (ADHD), depression, and anxiety.
Age and sex may also play a role in the onset and development of OCD. OCD is usually diagnosed before the age of 25, with many people first showing symptoms during childhood or adolescence. It’s rare (though not impossible) for someone to be diagnosed with the disorder after the age of 35.
Meanwhile, studies suggest that women are approximately 1.6 times likelier than men to develop OCD during their lifetime.
OCD and Comorbidity
It’s common for people with OCD to have more than one mental health condition. A 2021 review and meta-analysis found that 69% of people with OCD had at least one other mental illness over the course of their lifetime.
Diagnosis and Tests
If you suspect you may have OCD, your healthcare provider can refer you to a mental health therapist. They can diagnose you with OCD using your medical history, an understanding of your symptoms, and the criteria in the DSM-5.
Your healthcare provider may also perform a physical exam and other tests to rule out the possibility of any underlying physical conditions or comorbid mental health disorders.
In the DSM-5, OCD appears under the category of “obsessive compulsive and related disorders.” OCD-related conditions within this umbrella category include:
- Hoarding disorder: While hoarding is sometimes a symptom of OCD, hoarding disorder can also be diagnosed and treated as a distinct mental health condition. People with hoarding disorder have extreme difficulties in discarding items and controlling their impulses to collect items—even when their collections negatively affect their relationships, safety, health, and/or finances.
- Skin picking disorder: People with skin picking disorder, also known as excoriation disorder or dermatillomania, pick at their skin persistently. Harmful effects may include skin lesions, emotional distress, and social isolation.
- Trichotillomania: People with trichotillomania experience hair loss, emotional distress, difficulties with self-image, and poor self-esteem due to a persistent, uncontrollable impulse to pull or pluck out their hair.
- Body dysmorphic disorder: Body dysmorphic disorder (BDD) involves an overwhelming preoccupation with one’s body and looks. People with BDD often spend a great deal of time, money, and energy to improve or “fix” their appearance.
Other conditions that are sometimes mistaken for OCD or may appear alongside it include:
- Obsessive-compulsive personality disorder: Obsessive-compulsive personality disorder (OCPD) is a mental condition that involves rigidity in thinking and behavior, excessive devotion to rules and perfectionism, and a preoccupation with maintaining control. OCD shares some symptoms with OCPD, but they are different conditions.
- Anorexia nervosa: Certain eating disorders, such as anorexia nervosa (AN), are often comorbid with OCD. Some research suggests that about 35% to 44% of patients with AN also meet the diagnostic criteria for OCD. Meanwhile, about 10% of female patients with OCD also have AN.
- Tourette syndrome: Tourette syndrome (TS) is a nervous system disorder that causes involuntary tics (repeated movements, sounds, and/or twitches). OCD and TS are related and often comorbid, especially in children and adolescents. About 60% of people with TS also meet the diagnostic criteria for OCD, and up to half of the children with OCD have experienced tics at some point.
How OCD Is Treated
Many people with OCD experience improvements with treatment. Studies suggest that about 50% of people with OCD will experience full remission of their symptoms after treatment. Many others are able to significantly improve their quality of life over time.
Psychotherapy is the typical first-line treatment for OCD. Many people with OCD benefit from a particular type of cognitive behavioral therapy (CBT) known as exposure and response prevention (EX/RP) therapy. In EX/RP therapy, patients gradually learn to confront their obsessions (exposure) while resisting the urge to perform compulsions in response (response prevention).
In some cases, antidepressants may be used in combination with psychotherapy to ease OCD symptoms. Selective serotonin reuptake inhibitors (SSRIs)—antidepressants that work to increase the level of serotonin in the brain—have been found to be especially effective in treating people with OCD, particularly at higher dosage.
What Is Serotonin?
Serotonin, or 5-hydroxytryptamine (5-HT), is a neurotransmitter—a chemical messenger—in the central nervous system that helps to regulate mood, emotions, memory, pain tolerance, sleep, appetite, and sexual desire.
Obsessive-compulsive disorder (OCD) is a chronic mental disorder that involves obsessions (intrusive, persistent, and unwanted thoughts or worries), compulsions (rituals or behaviors that one feels driven to repeat), or both.
There is no single known cause of OCD. Multiple factors, including genetics, trauma, and differences in brain structure, may contribute to the development of the condition.
Researchers have identified several common subtypes of OCD. OCD symptoms often fall into one of four clusters: checking, order/symmetry, germs/contamination, or rumination/intrusive thoughts. Other subtypes of OCD include hoarding and somatic obsessions.
OCD can be diagnosed by a mental health therapist using the criteria in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5). It is typically treated with antidepressants, psychotherapy, or both.
A Word From Verywell
Many people feel nervous to talk about their obsessions and compulsions with a healthcare provider. However, OCD is common, treatable, and manageable. If you think you may have OCD, talk to your healthcare provider about seeing a specialist to address your symptoms and improve your quality of life.
Frequently Asked Questions
There is no single agreed-upon list of OCD subtypes. However, many researchers agree that OCD obsessions and related compulsions often fall into five main clusters. These symptom clusters include contamination, ordering and symmetry, rumination (including over-responsibility for harm, illness anxiety, and persistent doubts), taboo impulses and imagery (such as violent and/or sexual images), and hoarding.
The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) does not specify different levels of OCD severity. However, the DSM-5 does categorize OCD according to the patient’s level of insight.
A person with OCD who has good or fair insight knows that their obsessions are not based on reality, while someone with poor insight thinks their obsessive beliefs are probably true. Meanwhile, a person with absent insight is entirely convinced that their beliefs are true.
OCD was previously categorized as an anxiety disorder. However, in 2013, the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) moved OCD out of that category and placed it under the umbrella of “obsessive compulsive and related disorders.” Other OCD-related disorders include hoarding disorder, body dysmorphic disorder, trichotillomania, and skin picking disorder.
On its own, the trait of perfectionism is not a form of OCD. However, research suggests that perfectionism is common among people with OCD.
A 2019 study found that children and adolescents who exhibited a tendency towards perfectionism were more likely to develop severe OCD symptoms and to meet the diagnostic criteria for OCD.