Most people imagine obsessive-compulsive disorder (OCD) as visible rituals like washing hands, checking locks, or counting. But there’s another form that doesn’t fit the stereotype. On the surface, it can look just like anxiety or constant overthinking.
Clinically, it’s called “Primarily Obsessional OCD,” often shortened to “Pure O.” And because the compulsions are hidden (happening in the mind rather than in overt behavior), this form of OCD is often missed or misdiagnosed as generalized anxiety disorder (GAD). Unfortunately, when that happens, even well-intentioned therapy can accidentally make things worse.
What Is “Pure O” OCD?
People with “Pure O” OCD experience unwanted, distressing intrusive thoughts that may feel alien, morally threatening, or intolerably uncertain. These can center on themes like harm, relationships, identity, morality, or health.
What makes it OCD, not just anxiety, is what happens next: the mental rituals.
Instead of washing hands or checking the stove, someone with “Pure O” might:
- Replay a memory to make sure they didn’t do something wrong.
- Mentally review evidence to feel certain they love their partner.
- Analyze “why” they had a thought and what it “means.”
- Seek reassurance, either aloud or silently, to relieve uncertainty.
Even though these rituals happen in the mind, they serve the same function as any other compulsion: to reduce distress and restore a fleeting sense of certainty. And just like all compulsions, they backfire, making intrusive thoughts stronger over time.
Why “Pure O” OCD Is Often Misdiagnosed as Generalized Anxiety Disorder
On the surface, “Pure O” can look a lot like chronic worry. Someone may appear introspective, analytical, or “just anxious.” But the function of their thinking is different.
- In GAD, worries usually involve real-life concerns (work, finances, safety) and can serve to prepare for possible outcomes.
- In OCD, obsessions center on feared possibilities, which are often unlikely or ego-dystonic, and the thinking aims to neutralize or undo the anxiety.
Because “Pure O” involves so much silent mental checking, even experienced clinicians can confuse it with generalized anxiety, depression, or rumination. In fact, research suggests that nearly half of people with OCD initially receive another diagnosis before the OCD is recognized.
That delay matters: insight-oriented or reassurance-based treatment for anxiety can unintentionally strengthen the OCD cycle.
When Insight-Oriented Therapy Feeds the Cycle
In therapy, curiosity and reflection are usually healing. But with OCD, the use of reflection can become part of the problem.
When therapy focuses on analyzing “why” a thought occurred, or spends session after session reassuring the client that they’re not a bad person, it can actually reinforce mental compulsions the same way checking a lock reinforces the fear it might be open.
Every time uncertainty gets soothed through reassurance or explanation, the brain learns, “That was dangerous and I can’t handle not knowing.”
Common examples of therapy pitfalls for “Pure O” include:
- Repeatedly exploring the content of intrusive thoughts (“But why did I think that?”).
- Engaging in co-rumination, therapist and client analyzing possibilities together.
- Framing intrusive thoughts as “unresolved issues” to be interpreted or solved.
These approaches can deepen the uncertainty-avoidance loop that drives OCD.
This doesn’t mean insight is always harmful. It means that in OCD treatment, insight must be balanced with behavioral learning. The goal isn’t to explain the thought but to help the client learn they can tolerate it without neutralizing it.
What Actually Helps: Evidence-Based Treatment for “Pure O” OCD
The gold-standard treatment for OCD, including “Pure O,” is Exposure and Response Prevention (ERP), a form of cognitive-behavioral therapy recommended by the American Psychological Association.
ERP teaches clients to face their feared thoughts or situations (exposure) while resisting the urge to perform mental or behavioral rituals (response prevention). Over time, the brain relearns that anxiety and uncertainty are tolerable.
Another effective approach is Acceptance and Commitment Therapy (ACT), which complements ERP by helping people:
- Gain distance from intrusive thoughts instead of analyzing them.
- Accept uncertainty as a normal part of being human.
- Reconnect with values by shifting focus from “figuring it out” to “living fully.”
Both ERP and ACT directly target the mechanism that drives “Pure O”: the urge to eliminate doubt.
When someone learns, “I can have that thought and still be okay,” the obsession loses its grip.
How to Tell If It’s OCD or GAD
While only a licensed clinician can make a diagnosis, there are clues that your anxiety may be OCD rather than GAD:
| If you notice yourself… | It may be OCD if… |
|---|---|
| Constantly reviewing thoughts or memories | The review aims to feel certain you didn’t do something wrong |
| Seeking reassurance from others | You feel temporary relief but the question keeps returning |
| Analyzing “why” you had a thought | The analysis is driven by distress, not genuine curiosity |
| Feeling trapped in cycles of doubt | The topic changes, but the feeling of uncertainty never does |
If that pattern sounds familiar, you’re not alone and you’re not “just overthinking.” There’s a name for it, and there’s treatment that works.
The Takeaway
“Pure O” OCD is one of the most misunderstood forms of the disorder. Because its compulsions are mental and invisible, it’s often mislabeled as generalized anxiety or overanalyzing. And when the therapy approach focuses on insight instead of acceptance, clients can unintentionally be guided deeper into the cycle.
But with evidence-based treatment like ERP and ACT, recovery is within reach. These therapies help people step out of the trap of analysis and into a life guided by values, not fear.
Ready to Begin?
At Vivid Psychology Group, we specialize in helping people untangle obsessive-compulsive patterns, including “Pure O” presentations that have been missed or misunderstood. If you’ve been caught in loops of doubt, reassurance, or mental checking, we can help you learn to relate to those thoughts differently and regain your confidence in living.
Reach out to schedule a consultation with one of our therapists trained in ERP and ACT for OCD.
Vivid Psychology Group provides in-person therapy in Englewood (south Denver), Colorado, and virtual treatment in most U.S. states.
