Pure O: Does It Really Exist or Is It Just a Trendy Label?
In recent years, the term “Pure O” has gained traction across social media, mental health forums, and even therapy rooms. But what exactly is Pure O? Is it a legitimate clinical concept or just another modern buzzword?

At The London Psychologist Clinic, we aim to bring clarity to the noise. This blog explores what Pure O really is, how it's recognised (or not) in diagnostic manuals like the DSM-5, and what the latest evidence says about symptoms, causes, and treatments.

What Is “Pure O”?
“Pure O” stands for Purely Obsessional OCD, a form of Obsessive-Compulsive Disorder (OCD) in which the compulsions are primarily mental rather than physical. While traditional OCD is often characterised by visible behaviours like hand-washing or checking, Pure O typically presents with distressing, intrusive thoughts and covert mental rituals.

Common intrusive themes in Pure O include:

Sexual thoughts (e.g., paedophilic OCD, incest, or taboo fantasies)

Religious or blasphemous obsessions (scrupulosity)

Fear of harming others (e.g., accidentally stabbing someone)

Existential or philosophical rumination

Doubts about identity, relationships, or morality

Unlike typical OCD, the compulsions here often involve:

Repeated mental reviewing

Seeking reassurance

Silent praying

Avoidance of specific thoughts or stimuli

Thought neutralising or "cancelling" rituals

Is Pure O in the DSM-5?
The DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition) does not include “Pure O” as a separate diagnostic entity. Instead, it categorises it under the broader umbrella of Obsessive-Compulsive Disorder (OCD).

The DSM-5 definition of OCD allows for obsessions and/or compulsions that may be mental, behavioural, or both. So, while “Pure O” isn’t formally listed, its symptoms fit squarely within the diagnostic criteria for OCD—just without the classic visible compulsions.

Is Pure O Just a Trendy Label?
It's a fair question—and one that reflects growing concerns around pop-psychology terminology. However, the concept of obsessional OCD without visible rituals isn’t new.

Terms like “pure obsessional” have appeared in clinical literature as far back as the 1990s (e.g., Baer, 1994), and cognitive-behavioural therapists have long acknowledged this subtype. What’s changed is public awareness—thanks largely to the internet and growing mental health literacy.

So, while “Pure O” is not a clinical term, it describes a very real experience that aligns with how OCD presents in many individuals. It’s not a trend; it’s a legitimate form of OCD.

How Does Pure O Present?
Though each person’s experience is unique, Pure O often follows a cycle of:

Intrusive thought – often disturbing, taboo, or anxiety-inducing

Emotional reaction – intense guilt, fear, or shame

Mental compulsion – trying to neutralise or “make sure” the thought isn’t true

Short-term relief, followed by the thought returning

The core struggle isn’t the content of the thought—it’s the meaning the individual attaches to it, and the mental rituals used to manage the anxiety.

What Do the Studies Show?
Research consistently supports the validity of Pure O-type presentations within the OCD spectrum. Key findings include:

Salkovskis et al. (2003) and Clark & Purdon (1993) found that the intrusive thoughts in Pure O are not fundamentally different from those in classic OCD—only the compulsive response differs.

Abramowitz et al. (2010) confirmed that people with Pure O-type symptoms experience similar levels of impairment and distress as those with physical compulsions.

CBT trials show similar response rates for Pure O and classic OCD, particularly when exposure and response prevention (ERP) is adapted for mental compulsions.

What Causes Pure O?
Like all forms of OCD, Pure O is thought to arise from a combination of:

Genetic predisposition

Neurobiological factors (e.g., abnormal serotonin transmission)

Cognitive-behavioural patterns (e.g., thought-action fusion, intolerance of uncertainty)

Environmental triggers, such as stress, trauma, or personal values that clash with the intrusive thought

Importantly, the content of the obsessions often reflects a person’s deepest fears or values. For example, a gentle and empathetic person might be terrified of harming others.

Effective Treatments for Pure O
Treatment for Pure O follows the same principles as traditional OCD:

1. Cognitive-Behavioural Therapy (CBT) with ERP
The gold-standard treatment involves:

Exposure to feared thoughts (e.g., imagining a taboo scenario)

Prevention of mental rituals or reassurance-seeking

Therapists at The London Psychologist Clinic are specially trained to adapt ERP for Pure O by targeting covert compulsions.

2. Medication
SSRIs (e.g., fluoxetine, sertraline) can reduce the intensity of intrusive thoughts and anxiety, making therapy more effective.

3. Metacognitive Therapy (MCT) and ACT (Acceptance and Commitment Therapy)
Newer approaches help clients change their relationship with thoughts rather than trying to eliminate them.

Final Thoughts: Valid but Misunderstood
Pure O is not a clinical myth or fleeting trend. It’s a real and distressing manifestation of OCD, often hidden behind a calm exterior but deeply disruptive internally. While the DSM-5 doesn’t give it a name, it absolutely recognises it.

At The London Psychologist Clinic, we believe in seeing beyond labels to understand each client’s individual experience. Whether you call it Pure O or obsessional OCD, help is available—and recovery is possible.

Need Support?
If you or someone you know is struggling with intrusive thoughts or obsessive thinking, book a confidential consultation with one of our experienced psychologists. We offer evidence-based treatment in a compassionate, stigma-free environment.