“Pure obsessional OCD” is a misnomer. People with “pure O” do have compulsions, but the compulsions are mostly mental.

Many people have mental rituals such as repeating an affirmation or running through a to-do list for the day. But people who feel compelled to carry out mental rituals in response to distressing, persistent intrusive thoughts may have pure obsessional obsessive-compulsive disorder (OCD).

“Pure O” is not a clinical or diagnostic term, and the Diagnostic and Statistical Manual of Mental Disorders, fifth edition, text revision (DSM-5-TR) doesn’t designate pure O OCD as a separate diagnosis. However, many people use this term to describe their experience of OCD.

Pure obsessional OCD may also be called primarily obsessional OCD.

Because pure O OCD involves internal mental compulsions instead of visible physical compulsions, it’s not always easy to identify.

Pure obsessional OCD, commonly referred to as “pure O,” is a subtype of OCD.

Unlike people with the classic presentation of OCD, who may have physical compulsions such as handwashing or checking, those with pure O experience internal, hidden compulsions. These compulsions can be mental rituals or processes in response to distressing obsessive thoughts.

The term “pure O” is somewhat misleading because people with this condition do have compulsions. However, the compulsions are not visible. Researchers have suggested that the term is a misnomer.

The main difference between classic OCD and pure O is the nature of the compulsions. In pure O, compulsions might involve going over an event repeatedly in your mind, seeking reassurance, or mentally counteracting or neutralizing an obsessive thought.

No. Although a mental health professional may use the term “pure O OCD” to describe your condition, pure obsessional OCD is not a separate diagnosis.

All subtypes of OCD — such as hoarding OCD, harm OCD, and scrupulosity — fall under the same diagnosis of OCD.

To diagnose OCD, a mental health professional will find out whether you fit the following criteria:

  • You experience obsessions, compulsions, or both.
  • Your obsessions and compulsions are disruptive and distressing and/or take up an hour or more of your day, every day.

The names of these OCD types are not clinical terms, but they can help people with OCD describe their experiences. “Pure O” can be a useful term because it captures the specific experience of having internal compulsions, distinguishing it from the experience of outward compulsions.

Pure O OCD symptoms involve both obsessions and compulsions, but the compulsions are usually mental.

Obsessions are intrusive, persistent, distressing thoughts that are challenging to get rid of.

Compulsions are rituals or actions you carry out to get rid of the obsessions or reduce your anxiety around them.

In the case of pure O compulsions, these rituals or behaviors are mental. You may experience compulsions such as praying, repeating mantras, and mentally replaying past events.

Pure O OCD can center on thoughts, images, and even sounds relating to any theme. Many people experience a variety of OCD “themes” — for example, someone might experience anxiety around germs and becoming ill in addition to relationship-related obsessions.

Pure O obsessions

Pure O obsessions can relate to any topic or issue. They’re different from day-to-day worries or fleeting intrusive thoughts in that they’re persistent and highly distressing.

Some examples of common OCD obsessions are:

  • upsetting thoughts or images that may be violent, sexual, or blasphemous
  • fears of harming yourself or someone else
  • doubts about your sexual orientation (sometimes called homosexual OCD)
  • worry that you said or did something bad in the past
  • fears of saying something offensive, rude, or obscene
  • fear that you or your family will become ill
  • fear about contaminating food or objects with germs
  • intrusive, distressing sounds playing over and over in your head
  • doubts about your relationships or feelings about your partner

Any fear, image, or idea can become the center of OCD obsessions.

Pure O compulsions

Despite the name of the condition, pure O OCD does involve compulsions — but the compulsions are mental.

You may experience compulsions such as:

  • mentally counting
  • reassuring yourself
  • mentally repeating phrases, affirmations, or mantras
  • mentally reviewing past events
  • ruminating excessively
  • visualizing images that comfort you

Many people engage in some of these behaviors some of the time. Self-reassurance and visualization are not always compulsions in themselves.

But in OCD, you engage in compulsions to soothe the distress associated with the obsession. The point isn’t always what you do but why you do it.

Many people with pure O OCD find it challenging to pinpoint why they’re engaging in compulsions. Some might realize that their mental compulsions aren’t helpful and are contributing to their anxiety.

If you think you’re experiencing obsessions or compulsions, it’s a good idea to speak with a therapist who specializes in treating OCD.

It’s not entirely clear why some people develop OCD and others do not. But some factors can increase your chances of developing OCD.

Risk factors include:

  • genetics
  • certain patterns of thinking, such as an inability to cope with uncertainty, an increased sense of responsibility, and magical thinking
  • extreme stress or trauma
  • other mental health conditions
  • pregnancy and childbirth (which can lead to postpartum OCD)

Autoimmune disorders may also trigger OCD or OCD-like symptoms. In children, streptococcal infections (such as strep throat) can lead to the development of pediatric autoimmune neuropsychiatric disorders associated with streptococcus (PANDAS). PANDAS causes symptoms similar to those of OCD and Tourette syndrome.

Like other kinds of OCD, pure O is treatable. With the right treatment, many people can find relief from their symptoms.

Treatment options for OCD include:

If needed, you may also benefit from:

  • Deep brain stimulation: This surgical procedure involves delivering electrical pulses into areas of your brain associated with OCD.
  • Transcranial magnetic stimulation: This noninvasive procedure involves delivering magnetic pulses to your brain.

Different treatments (or combinations of them) may work for each person. For example, not everyone with OCD will benefit from medication. And for some people, talk therapy alone is enough to manage the symptoms.

You may also benefit from lifestyle strategies such as maintaining a regular sleep schedule and exercising to relieve stress.

Not sure how to find a therapist? Our guide can help.

Although it’s called “pure obsessional” OCD, people with this form of OCD do experience compulsions. However, those compulsions tend to be mental and are therefore not noticeable to others.

OCD can be difficult to cope with, but it is treatable. Like other forms of OCD, pure O OCD can be treated with medication, therapy, or both.