OCD or Psychosis? Understanding 7 Insights for Clarity
Not long ago, I was sitting in my home office in Edinburgh, streaming the 30th Annual OCD Conference online. You’d think that kind of thing would feel less intense than being in the room. But honestly? This one presentation totally stopped me in my tracks. It was titled “Is it OCD or Psychosis?”—and it hit a nerve.
One of the speakers, Dr Robert Hudak, described a clinical landscape I’m all too familiar with: patients who seem to meet the criteria for both OCD and psychosis. And here’s the issue—they’re often misunderstood, misdiagnosed, or mistreated. His presentation covered the diagnostic challenges, medication complications, and how therapists can adapt CBT and ERP to help these clients better.
So, I decided right then and there that I wanted to share what I had learned with you. In plain English. As if we were having a cuppa and just chatting this through. Because if you—or someone you love—is dealing with obsessive thoughts that don’t quite “fit the box,” then knowing the difference could really change everything.
Why the confusion even happens
Right, let’s start simple. OCD and psychosis are two different beasts—but they can look oddly similar from the outside. You might hear someone say, “I’m convinced something terrible will happen unless I check the oven 27 times.” Another person might say, “The police have bugged my flat and I can hear them through the walls.” One is usually anxiety-based. The other can be part of a psychotic disorder. But here’s the tricky part—they can both feel completely real to the person saying them.
And you know what? That overlap causes all kinds of confusion—even for professionals. That’s why this topic got so much attention at the OCD conference. It’s not about diagnosing too quickly. It’s about listening deeply, asking the right questions, and understanding what’s really going on under the surface.
The basics – OCD vs Psychosis
Let’s break it down. Obsessions in OCD are unwanted. They’re ego-dystonic—which means they go against your values and how you see yourself. They create anxiety and distress. That’s why people with OCD often try to neutralise the thought with rituals or compulsions.
Delusions, on the other hand, are ego-syntonic. That means the belief fits with the person’s sense of reality. It doesn’t cause anxiety—it feels true. Delusions are usually fixed beliefs that don’t budge, even when someone presents evidence to the contrary.
And hallucinations? They’re a whole other layer. People might see or hear things that aren’t there. In OCD, hallucinations are rare. But intrusive thoughts? Very common. The key is knowing whether what someone hears or sees is interpreted with fear or conviction.
The tricky middle bit: poor insight and overvalued ideas
Now, here’s where it gets sticky. Some people with OCD have poor or even absent insight. That means they’re not fully aware that their fears are irrational. They might start to sound delusional—but they’re still driven by anxiety. There’s also this thing called “overvalued ideas.” These are beliefs that aren’t quite delusions, but they’re held strongly and cause distress.
The conference presentation explained that insight is a moving target. Even within a single session, someone might flip from recognising a fear as irrational to believing it’s true. Insight isn’t static—it changes depending on mood, stress levels, and sleep. This variability is why standard assessments, such as the Brown Assessment of Beliefs Scale, are so useful—they provide a more reliable measure of how deeply someone holds a belief.
What is Schizo-Obsessive Disorder?
Schizo-Obsessive Disorder describes the co-occurrence of schizophrenia and OCD in the same individual. According to Dr Hudak, it’s a special clinical subtype—people who meet full diagnostic criteria for both disorders. The tricky bit? Some symptoms look like both. Is that repeated checking driven by an obsession, or is it responding to a paranoid delusion? The function and emotional tone of the behaviour are what help us tell the difference.
In his talk, Hudak outlined criteria: obsessions must be distinguishable from psychotic symptoms, not purely caused by hallucinations or delusions, and not a side-effect of medication. If a patient with schizophrenia shows obsessive-compulsive symptoms that persist independently from psychotic episodes, it’s more likely true comorbidity.
People in this group often respond poorly to standard antipsychotics alone. Some second-generation antipsychotics, like clozapine, can even trigger or worsen OCS. This means meds like SSRIs need to be carefully introduced, often alongside CBT/ERP with modifications.
Real-life cases from the conference
One story I can’t forget is about a woman with OCD who was convinced that her clothes released lint, which would feel lonely once it hit the floor. It sounds bizarre, right? But she knew it was irrational—and she felt distressed by it. That’s OCD.
Another case involved a patient with schizophrenia who compulsively checked vents and doors for hidden cameras. He had some insight, and his rituals were driven by anxiety. Again, OCD was in the mix.
The presenters emphasised that even when the content seems strange or unusual, we shouldn’t jump to psychosis. The insight, distress level, and compulsive responses matter far more than whether a thought sounds “bizarre.”
How common is it?
In the UK, about 1 in 100 people live with schizophrenia, and about 1-2% experience OCD (NICE, 2005). But up to 25% of people with schizophrenia show some obsessive-compulsive symptoms. That’s not rare. That’s one in four. Therefore, it’s vital that we discuss this further.
At the conference, it was also pointed out that early onset OCD may be a risk factor for later development of a psychotic disorder, especially if combined with poor insight, social withdrawal, and a family history of psychosis. So it’s not just about what symptoms someone has today—it’s about their developmental journey.
Can OCD turn into psychosis?
Short answer: not really. Most people with OCD don’t go on to develop schizophrenia. The risk is around 1-2% (Eken, 2025). But OCD can come with such poor insight that it looks like psychosis. The difference lies in the distress, the motivation behind the thoughts, and how flexible the beliefs are.
We also have to consider trauma. Some people with OCD or psychosis have a history of trauma, which can make their thoughts or behaviours even harder to interpret. At the conference, clinicians discussed how trauma-related OCD symptoms—like those involving guilt, contamination, or hypervigilance—can overlap with paranoid features of psychosis.
ERP still works – with tweaks
Here’s the good news. Exposure and Response Prevention (ERP), the gold-standard treatment for OCD, still works—even in complicated cases. But it needs adapting. When someone has low insight or co-occurring psychosis, we take things slower. We might combine ERP with medication or use more behavioural experiments.
Dr James Claiborn emphasised that standard ERP might overwhelm someone with poor insight, so building trust and motivation is key. Tools from Acceptance and Commitment Therapy (ACT) or Motivational Interviewing can help clients stay engaged when ERP feels scary or counterintuitive.
And yes, ERP for someone with schizo-obsessive disorder might look different. Hierarchies may be simpler, exposures shorter, and rituals more covert. Sometimes it’s not about eliminating compulsions entirely—but reducing them enough that life becomes manageable.
What if the person is already on antipsychotics?
Some antipsychotics can worsen OCD symptoms. Clozapine is known for this. But others, like aripiprazole or risperidone, can actually help. At the conference, they discussed how aripiprazole, due to its partial dopamine agonist action, may have anti-obsessional effects when added to SSRIs.
If someone is already on antipsychotics and develops OCS, it doesn’t mean their diagnosis has changed—it might mean the meds need tweaking. Medication reviews are essential, especially if a patient’s insight is declining or rituals are increasing.
Insight changes everything
People often ask me, “How do I know if it’s OCD or psychosis?” Well, it depends. But insight is key. If the person knows the thought is irrational, even just a little, it’s more likely OCD. If they’re convinced it’s real, and it doesn’t cause them distress—that’s heading toward psychosis.
But here’s the twist: insight can change over time. Someone might be convinced one day, and the next, start to question the thought. That’s why ongoing assessment is so important.
We sometimes use tools like the Brown Assessment of Beliefs Scale to measure insight. It provides us with a more objective view of how fixed or flexible the beliefs are. Regular reassessment helps guide treatment decisions.
Why this matters in therapy
Imagine being given the wrong label. Imagine trying ERP when your therapist treats you like you’re psychotic—or vice versa. Misdiagnosis can stall progress. However, when we get it right and the therapy aligns with the person’s experience, recovery becomes possible.
As a CBT therapist based in Edinburgh specialising in OCD treatment, I work with clients all across the UK. Whether you’re unsure about your thoughts, confused by your symptoms, or feeling mislabelled—there’s a way through. I use ERP, but I adapt it because everyone’s mind is different.
I also work closely with psychiatrists, particularly in complex or blended cases. The collaboration between therapy and medication management is what truly supports long-term recovery.
Final thoughts
This isn’t about slapping a label on someone. It’s about understanding the function of a thought. Is it ego-dystonic or ego-syntonic? Is there distress? Is there resistance? And most importantly—how is it impacting the person’s daily life, relationships, and sense of self?
When we think diagnostically, we often focus on the labels: OCD, schizophrenia, schizo-obsessive disorder. However, in real-world therapy, what matters is how these experiences unfold day-to-day. Is the person suffering? Are they avoiding life, stuck in rituals, isolated, or overwhelmed? Then let’s treat that.
What I took away from the conference is this: the overlap between OCD and psychosis doesn’t have to mean confusion or chaos. It means we need to be more nuanced. More thoughtful. And more collaborative. We need to create safe spaces where people can explore their thoughts without fear of being misunderstood.
There’s no one-size-fits-all answer here. Some people need ERP with lots of psychoeducation and structure. Others require a blend of CBT for psychosis, medication, trauma-informed care, and value-driven approaches like ACT. The best treatment isn’t just evidence-based—it’s person-centred.
So if you’re struggling with thoughts that scare you, confuse you, or make you question your reality—please know that help exists. You’re not alone. And your experience is valid, even if it doesn’t fit neatly into a diagnostic category.
What do you think? Could understanding the difference between OCD and psychosis change how we support people? Could understanding the difference between OCD and psychosis change how we support people?
References:
Hudak, R. (2025). IOCDF 2025 OCD and Psychosis Presentation. 30th Annual OCD Conference.
Eken, S.C. (2025). OCD and Psychosis: Medication Management. 30th Annual OCD Conference.
Claiborn, J. (2025). Obsessive-Compulsive Disorder and Schizophrenia. 30th Annual OCD Conference.
Phillips, K. A., et al. (2002). Delusional vs. non-delusional body dysmorphic disorder: Clinical features and response to fluoxetine. American Journal of Psychiatry, 159(12), 1969–1971.
Himle, J. A., et al. (2006). Insight as a predictor of treatment outcome in CBT for OCD. Journal of Anxiety Disorders, 20(5), 653–659.