Pure O: Primarily Obsessional OCD Symptoms & Treatments

Woman with Pure O experiencing obsessions
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When many people think of obsessive-compulsive disorder, they focus on the obvious behaviors that are often a symptom of the disorder such as compulsive hand-washing, constant cleaning, repeated checking, or a need for symmetry. While these actions might be the most noticeable signs of OCD, it is important to understand that not all cases of the disorder are the same. Compulsions are only one aspect of this disorder, and it is the obsessional component that tends to be overlooked. In some cases, people experience these obsessions without engaging in the behavioral compulsions that are often considered a hallmark of OCD. This presentation of the disorder is sometimes referred to as pure O, also known as purely obsessional OCD or primarily cognitive obsessive-compulsive disorder.

What Is Pure O?

Pure O is a form of OCD marked by repeated, intrusive, and uncontrollable thoughts (or obsessions) that are usually not accompanied by outward behavioral compulsions. While an individual experiencing pure O may not engage in obvious physical behaviors related to their intrusive thoughts, such as counting, arranging, or hand-washing, the disorder is instead accompanied by hidden mental rituals.

Obsessive-compulsive disorder (OCD) itself involves having reoccurring and uncontrollable thoughts (obsessions) and behaviors (compulsions). For example, a person with OCD might have uncontrollable thoughts about germs and cleanliness that result in an urge to repeatedly wash his or her hands over and over again.

Pure O is sometimes mistakenly seen as a “less severe” form of OCD, yet those who experience symptoms of this disorder find that the characteristic intrusive thoughts can be very disruptive and distressing. While people who do not report engaging in compulsions are sometimes referred to as having "pure O" or "purely obsessional disorder," this variant is not listed as a separate diagnosis in the DSM-5, the diagnostic manual used by many physicians, psychiatrists, and psychologists.

Common Symptoms of OCD

People who experience "purely obsessional" form of this disorder experience a range of OCD symptoms, although the obvious compulsions are absent. According to the DSM-5, OCD is characterized by obsessions and/or compulsions.

Obsessions involve:

  • Repeated intrusive images, thoughts, and impulses that create a great deal of distress
  • Thoughts that are not related to excess worries and stress in real life
  • Recognition that these thoughts arise from within the individual's own mind
  • Making attempts to ignore, suppress, or neutralize the obsessive thoughts

Obsessions can center on somatic, sexual, religious, or aggressive thoughts as well as concerns with things such as hoarding, checking, symmetry, contamination, and arranging.

Compulsions involve:

  • Repetitive actions, either behavioral or mental, that a person feels compelled to perform as a result of obsessive thoughts
  • Engaging in actions intended to reduce distress related to the obsessions

In addition to experiencing obsessions and/or compulsions, the DSM-5 diagnostic criteria also stipulate that:

  • The obsessive-compulsive symptoms must not be due to the physiological effects of a substance, such as a side effect of a medication or illicit drug. The symptoms must also not be due to the presence of some other medical condition.
  • The obsessions and compulsions must be time-consuming, often taking more than one hour per day, or they must create significant distress or impairment in occupational, social, or other critical areas of life functioning.
  • The symptoms must not be better attributable to another mental disorder such as generalized anxiety disorder, body dysmorphic disorder, hoarding disorder, substance-related disorders, or major depressive disorder.

Symptoms of Pure O

So what is it about the purely obsessive variation of symptoms that causes some people to refer to this subset of symptoms as pure O?

Two of the characteristic symptoms that are sometimes used to distinguish pure O include the following:

The presence of mental rituals designed to reduce distress. Such rituals can include mentally reviewing memories or information, mentally repeating certain words, mentally un-doing or re-doing certain actions.

Repeatedly seeking reassurance. This reassurance-seeking can be problematic because many patients may not even recognize it as a compulsion. Such reassurance-seeking may involve looking for self-assurance, researching online, avoiding anxiety-provoking objects or situations, and asking others for assurance. An added complication of this symptom is that family and friends may become fatigued or annoyed by these constant requests for reassurance, which may be perceived by others as neediness.

Previous studies have suggested that there may be as many as three to six different symptoms subtypes of OCD, including the so-called "pure O" form of the disorder. First described by Baer in a 1994 article in the Journal of Clinical Psychiatry, pure O was described as being composed of sexual, aggressive, and religious obsessions that were not accompanied by compulsions.

Later research suggested that the aggressive obsessions could be further divided into fears over impulsive harm and unintentional harm. Those thoughts centered on impulsive harm often center of what is sometimes termed "taboo thoughts" related to sex, religion, and aggression.

In a 2011 study, researchers found that individuals who experience the "pure obsessions" which are also sometimes described as "taboo thoughts" or "unacceptable thoughts" also engage in mental rituals or reassurance seeking as a way of managing their distress. Compulsions still exist in pure O, but they are much less obvious because they are almost entirely cognitive in nature.

Common Treatments for Pure O

Treatment for OCD, including pure O, often involves the use of medication in combination with psychotherapy, which may include cognitive-behavioral therapy, support groups, and psychological education.

Cognitive Behavioral Therapy for Pure O

Research suggests that cognitive-behavioral therapy (CBT) can be very effective at treating pure O OCD. However, it is essential that therapists and other mental health practitioners understand the necessity to also address the underlying mental rituals that characterize this subtype of symptoms. If the therapist believes that the patient only suffers from obsessions and does not also treat the mental rituals that accompany these cognitions, the treatment will not be as complete or effective.

Medications for Pure O

Medications may include selective serotonin reuptake inhibitors (SSRIs) or the tricyclic antidepressant clomipramine. Some side effects associated with the use of SSRIs include insomnia, anxiety, gastrointestinal upset, and sleepiness. One review of the research has suggested that approximately 40 to 60 percent of patients respond to treatment with SRIs with a 20 to 40 percent reduction in OCD symptoms.

The specific treatment used, whether medication alone, psychotherapy alone, or some combination of the two, depends upon the individual needs of each patient. For example, CBT may be used alone in patients who are averse to taking medications or those who are pregnant or nursing. Medication might be prescribed alone for patients who have poor motivation for insight-based treatments or who lack access to a CBT-trained mental health practitioners.

ERP for Pure O

In one review, researchers looked at earlier studies to see if certain symptoms subtypes of OCD responded better to certain treatment approaches. They found that in the majority of studies, OCD characterized by religious and sexual obsessions in the absence of compulsions (i.e., pure o) was associated with a poor response to treatments using SRIs and exposure and response prevention.

Exposure and response prevention, also known as ERP therapy, is a form of cognitive-behavioral and exposure therapy. It involves a trained therapist helping a client approach a fear object without engaging in any compulsive behaviors.

Clients intentionally expose themselves to the objects, images, situations, or thoughts that make them anxious or that are the subject of their obsessions, but are prevented from engaging in the compulsive behavior that typically follows these events. The goal of such therapy is to help patients learn how to effectively manage their symptoms without having to resort to acting upon compulsions in order to relieve mental distress.

Pure O: How Does It Differ From OCD?

So is pure O really a distinct form of OCD? What makes it different from the traditional diagnosis of obsessive-compulsive disorder? While some studies have suggested there may be different symptoms subtypes of the disorder, one study has suggested that the term pure O may be something of a misnomer. While people who experience these obsessions without any obvious behavioral compulsions, they do still engage in unseen mental rituals.

Why is it so important to note that these mental rituals still exist, even in the absence of behavioral rituals? "Recognition of compulsions performed by those previously considered purely obsessional can aid in the improved diagnosis and treatment of people with OCD," explains researcher and clinical psychologist Monnica T. Williams and her colleagues in their article "The Myth of the Pure Obsessional Type in Obsessive-Compulsive Disorder."

By understanding that such mental rituals exist, therapists and other mental health professionals can ask patients about these symptoms. Without such questioning and prompting, patients may be reluctant to describe the symptoms that they are experiencing or may not even be aware that they should discuss these symptoms.

A Word From Verywell

Pure O may not involve the outward behaviors that often come to mind when people think of OCD. However, the hidden mental rituals that characterize the purely obsessional form of the disorder are a type of compulsion, even though they may go unseen.

If you find yourself experiencing distressing obsessions and/or mental compulsions that are interfering with your life and daily functioning, consider talking to your doctor or a mental health professional. While these thoughts may seem disturbing at times, a trained expert can help you better understand your symptoms as well as the treatment options that may be available to you. Talking about your thoughts is not always easy, but taking this important step is the first part of getting the help you may need to find relief.

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  • Abramowitz, JS, Deacon, BJ, & Whiteside, SPH. Exposure Therapy for Anxiety: Principles and Practice. New York: The Guilford Press; 2011.
  • Starcevic, V & Brakoulias, V. Symptom subtypes of obsessive-compulsive disorder: Are they relevant for treatment? Aust N Z J Psychiatry. 2008;42(8):651-661. doi: 10.1080/00048670802203442.
  • Stewart S.E. Obsessive-Compulsive Disorder. In: Camprodon J., Rauch S., Greenberg B., Dougherty D. (eds) Psychiatric Neurotherapeutics. Current Clinical Psychiatry. New York: Humana Press; 2016.
  • Williams, MT, et al. The myth of the pure obsessional type in obsessive-compulsive disorder. Depression Anxiety. 2011;28(6):495-500. doi:  10.1002/da.20820