In obsessive-compulsive disorder, something profoundly destabilizing can happen: knowing that something is true and, at the same time, being unable to feel it is true enough to be able to stop.
It is in this gap between knowledge and lived certainty that doubt becomes suffering. And this is where treatment can begin.
Let’s imagine someone standing in front of a mirror. On the outside, everything appears composed: the face, the posture, the clothes, perhaps even the expression. At first glance, nothing reveals what is happening inside. Yet the reflection seems out of sync. Not because contact with reality has been lost. On the contrary, those suffering from obsessive-compulsive disorder often perfectly recognize the gap between what they think and what they consider reasonable.
They know they locked the door. They remember turning off the gas. They know they don’t want to hurt anyone. They know that the image that suddenly appeared doesn’t represent a desire or a choice. They know it. But they can’t feel it strongly enough.
E so they check again. They mentally retrace what happened. They look for a detail that will restore their certainty. They seek confirmation. For a few minutes, they calm down. Then something cracks again, and the question returns. It is perhaps precisely in this gap—between what is known and what can be internally felt as sufficiently certain—that we can approach one of the most intimate experiences of OCD.
This isn’t about a love of order. It isn’t mere perfectionism, nor an excess of precision. And it isn’t that slight eccentricity common parlance alludes to when someone says, almost casually, “I’m a bit obsessive.” It can be a profoundly debilitating condition. It takes up time, saps energy, and intrudes on work, studies, and romantic relationships. It transforms ordinary actions into exhausting trials and can do so even without any outward signs, because some compulsions take place entirely in the mind.
Obsessions are recurring, unwanted thoughts, images, or impulses that cause distress; compulsions are behaviors or mental acts performed in an attempt to reduce that distress or avert a feared consequence. They may involve contamination, responsibility for potential harm, the fear of having made a mistake, or the need for symmetry or completeness. At other times, they take on aggressive, sexual, religious, or moral content—precisely the kinds that are most likely to clash with the deep-seated values of those who experience them.
But the pain does not depend solely on the content that bursts into consciousness. It arises above all from the meaning attributed to it. Why did I think that? What if this says something about me? What if the mere fact that that scene came to mind means that, somewhere deep inside me, I might desire it? This is where the disorder touches an extremely sensitive area of identity: the fear that one’s inner world might turn into an accusation.
The research offers an important insight, as it puts one of the individual’s most painful beliefs into perspective: intrusive thoughts are not an experience exclusive to OCD. The human mental life also includes sudden associations, disturbing images, absurd ideas, or content that may even be contrary to our values. In 2023, Jean-Sébastien Audet, Lysandre Bourguignon, and Frederick Aardema published a systematic review with a meta-analysis of fifteen studies, involving a total of 1,891 participants.
Their work shows that what most distinguishes obsessive intrusions in obsessive-compulsive disorder is not simply their presence, but the way they are experienced: with greater distress, guilt, interference, persistence, and pervasiveness; and, when compared to other clinical conditions, with characteristics such as unacceptability, uncontrollability, and alienation from one’s sense of self. This distinction has enormous clinical value.
A thought is not an intention. An image is not a decision. A feared impulse is not the same as the desire to turn it into a behavior. These are simple statements to read and, at times, tremendously difficult to accept as true when one is living with the disorder.
Some obsessions are so far removed from the identity and values of those who experience them that they provoke an almost unbearable sense of shame. It may be relatively simple to tell a therapist that you check the lock ten times; it is much harder to confess to a violent, sexual, or blasphemous image that fills the person experiencing it with horror. In those moments, it is not just the content of the obsession that is feared.
One fears the other person’s gaze. “What will they think of me if I tell them?”
Here, the quality of the clinical encounter becomes fundamental. Even before addressing the symptom, it is necessary to create a space where it is possible to speak without the act of listening becoming judgmental and without understanding, in turn, turning into compulsive reassurance. The therapist does not treat the obsession as proof of a person’s identity or dangerousness. Instead, the therapist takes the suffering that the content of the obsession generates seriously. And for those who have spent years fearing that their thoughts define them, this difference can open a first crack in their isolation.
Even the time that elapses before receiving appropriate treatment illustrates how hidden OCD can remain. In 2022, Daniel Lucas da Conceição Costa and numerous colleagues studied 863 participants in a large multicenter sample. The median time between becoming aware of the distress caused by symptoms and starting specific treatment was four years. About one-third had sought help within two years, another third between two and nine years, and about one-third after ten years or more.
Behind these numbers, it’s easy to forget the lives involved.
There are mornings that begin with a check and continue with more checks. Conversations mentally replayed to the point of exhaustion. Hands washed yet again. Phrases repeated in silence. Memories scrutinized in search of a decisive detail. Questions directed at a loved one in the hope that an answer will finally quell the fear. The problem is that, often, the compulsion works. At least for a few minutes. The obsession causes tension; the ritual reduces it. The relief that follows reinforces the behavior and makes it more likely that, when a new doubt arises, the same solution will be used again.
It’s an understandable learning mechanism, driven by negative reinforcement: not a sign of weakness, nor a lack of willpower.
This is precisely where one of the disorder’s most painful traps lies: what begins as a form of protection ends up perpetuating the problem.
The more I try to control, the less I can trust my previous control. The more I seek absolute certainty, the more sensitive I become to the slightest possibility that something has been overlooked. The more I try to erase the doubt, the greater the authority I may end up attributing to it.
There is no single type of obsessive experience, however. In some cases, the fear of uncertainty prevails; in others, incompleteness, disgust, contamination, responsibility, the need for symmetry, or the fear of being morally culpable. Reducing every manifestation to a single mechanism would be simplistic. A diagnosis serves to recognize a clinical pattern; it can never fully capture the story of the person experiencing it.
Even the neurosciences have, in recent years, gradually moved away from overly simplistic explanations. For a long time, attention focused primarily on the cortico-striato-thalamic-cortical circuits. These systems continue to play an important role in neurobiological models of OCD, but the current picture is more complex and involves the interaction between distributed brain networks.
A systematic review published in 2024 in Cerebral Cortex by M. Prabhavi N. Perera and colleagues examined 166 studies—ten based on EEG and 156 on functional magnetic resonance imaging—focusing on brain connectivity in obsessive-compulsive disorder. The results do not point to a single, uniform brain “signature.”
Rather, differences emerge in communication within and between multiple networks, including those related to cortico-striato-thalamic-cortical circuits, the salience network, the default mode network, and the frontoparietal systems. But the authors themselves emphasize the presence of conflicting results and the need for further research.
This caution is invaluable. There is no single point in the brain where “obsession” can be localized, and a scan alone cannot reveal how a human being has learned to fear certain thoughts, what holds value in their life, the strategies used to protect themselves, or the shame they have lived with.
Biology matters. But biology does not erase biography. We can, however, use a metaphor—provided it remains a metaphor and is not mistaken for a proven neurophysiological explanation. In some obsessive experiences, it is as if the internal signal that normally allows us to say, “That’s enough; I can stop,” fails to gain enough strength. The action has been carried out. The information is available.
And yet that subjective sense of closure—which allows us to turn the page and move on—is missing. The mirror reflects an image, but the question remains: can we truly believe what we see?
Genetics also confirms just how complex the picture is. In May 2025, Nature Genetics published the most extensive genomic analysis of OCD available to date. Nora I. Strom, Zachary F. Gerring, Marco Galimberti, Dongmei Yu, and a large international group of researchers analyzed 53,660 cases and 2,044,417 controls from cohorts of European ancestry, identifying thirty independent loci associated with the disorder at the genome-wide significance level. This finding is important, but it must be interpreted correctly. “The DOC gene” has not been discovered.
On the contrary, the study confirms a highly polygenic genetic structure, in which a vast number of variants—each with a modest effect—contribute to overall vulnerability. Predisposition does not mean destiny. A genetic association alone does not predict who will develop the disorder, when they will develop it, or what form it will take. The relationship between biological vulnerability, development, experiences, environment, and learning is far more complex than any linear formula.
It is precisely this complexity that makes the perspective of neuroimmunomodulation, particularly interesting—provided it is approached with rigor. The nervous system, the endocrine system, and the immune system are not independent entities. They communicate and influence one another. This general principle is now well established. Much less clear, however, is the specific clinical significance of these interactions in obsessive-compulsive disorder.
A review published in 2024 in the Journal of Neuroscience Research by David Richer Araujo Coelho, Joshua D. Salvi, Willians Fernando Vieira, and Paolo Cassano discussed the available research on peripheral immune cells, cytokines, and possible neuroinflammatory processes in OCD, highlighting an interesting but still heterogeneous scientific field.
In the same year, a multivariate meta-analysis by Y. Chen and colleagues, published in European Psychiatry, pooled seventeen studies, including 573 patients with OCD and 498 healthy controls. Overall, no statistically significant differences emerged either for the set of pro-inflammatory and anti-inflammatory cytokines considered or for the individual cytokines analyzed. The heterogeneity of the studies was also high.
This means that, given the current state of knowledge, we do not have an immunological profile capable of identifying OCD, nor do we have a basis for describing the disorder, as a whole, as an inflammatory disease.
Stating this does not diminish the neuroimmunological perspective. It makes it more serious. Studying the dialogue between the brain, the endocrine systems, and the immune system remains scientifically important; transforming preliminary associations into proven causes, however, would be a mistake. Mature research also has the capacity to tolerate what it does not yet know.
In a certain sense, this is almost the opposite of what OCD imposes on those who suffer from it: the demand to receive an immediate, complete, incontrovertible, and definitive answer. On the therapeutic front, the evidence is much more solid.
A “State of the Art” review published in the BMJ on February 16, 2026, by Jonathan S. Abramowitz, Amitai Abramovitch, Dean McKay, and Alyssa Draffin confirms Exposure and Response Prevention (ERP) as the first-line psychological treatment for OCD in adults. On the pharmacological front, selective serotonin reuptake inhibitors (SSRIs) are the drugs of first choice; in moderate or severe cases, a combination of pharmacological treatment and ERP may be indicated, though this must, of course, be evaluated on a case-by-case basis.
A large meta-analysis published in 2024 in Psychological Medicine by Yingying Wang and colleagues, comprising 48 randomized controlled trials and 2,731 patients, also confirmed the overall effectiveness of psychological treatments in reducing obsessive-compulsive symptoms. Among the various approaches examined, ERP showed the broadest effect, despite significant heterogeneity among the studies. However, describing ERP merely as “exposing oneself to what is feared without performing the ritual” is technically correct but lacking on a human level.
Therapy should not become yet another place where someone feels compelled to prove they are strong enough. Exposure is planned, shared, and gradual. The goal is to understand which situations, thoughts, images, or sensations trigger the obsessive cycle and which strategies are used to neutralize it.
Then, gradually, the patient is given the opportunity to encounter that trigger without automatically resorting to the response that had previously provided relief. This isn’t about abandoning someone to their fear. It’s about staying by their side as they discover they can navigate through it without having to obey it. And, above all, the goal isn’t to replace the ritual with the therapist’s reassurance. If every doubt received a definitive answer from an external source, the logic of the disorder would risk remaining intact.
The transformation runs deeper. It concerns the possibility of leaving a question open without experiencing it as an emergency. The possibility of saying: perhaps I won’t have the absolute certainty I’m seeking, but that doesn’t mean I have to stop living.
This does not mean resigning oneself. It means restoring uncertainty to the place it occupies in everyone’s existence and stripping it of the exceptional power that the disorder has attributed to it.
Psychotherapy does not create a mind in which unwanted thoughts no longer arise. Such a mind is not part of human physiology. What can change is our relationship with what arises. An image can pass through consciousness without being subjected to interrogation. A thought can be unpleasant without becoming a confession. A sensation can be intense without constituting evidence. A doubt can exist without demanding an answer.
Even at the neurobiological level, data exist showing that psychotherapeutic treatment can be accompanied by measurable changes in brain activity. Callum Stephenson and colleagues conducted a systematic review with a meta-analysis of neuroimaging studies on patients with OCD undergoing cognitive-behavioral therapy that included ERP. The study, published online in June 2024 and appearing in the 2025 volume of the European Archives of Psychiatry and Clinical Neuroscience, included 193 patients and found, along with a reduction in symptoms, changes in activation in various brain regions.
Here, too, we must resist the temptation to oversimplify. We cannot conclude that psychotherapy “normalizes the brain” according to a single pattern, nor that there is a neurobiological indicator capable, at present, of confirming recovery. We can state something more modest and, perhaps, more fascinating: therapeutic learning and changes in experience can be accompanied by observable neurofunctional changes.
The psyche and biology do not tell two separate stories. When a person learns to refrain from performing a ritual, remains with a sensation that they would previously have immediately neutralized, interrupts a mental check, or confronts a situation they have avoided for years, they are having a psychological experience and, at the same time, are learning.
And every act of learning is also a biological event. Perhaps this is precisely why the word “healing” deserves to be spoken with care. It does not necessarily mean promising that no intrusive thoughts will ever appear again. It may mean that that thought no longer dominates the entire day.
That a question can remain unanswered. That it is no longer necessary to replay a conversation in one’s mind for hours on end. That you can love someone without constantly asking them for reassurance. That you can make a mistake without turning it into a verdict on your own identity. That it’s possible to trust yourself again—not because you’ve become infallible, but because you no longer expect to be.
OCD takes to an extreme something that belongs, to varying degrees, to the human condition.
None of us lives with absolute certainty. We cannot know precisely what will happen tomorrow. We cannot guarantee that we won’t make mistakes, that we won’t get sick, that we won’t be misunderstood, or that we won’t lose what we love. For many, this uncertainty remains in the background and still allows life to go on. In obsessive-compulsive disorder, however, it can turn into an incessant noise, capable of drowning out almost everything else.
Treatment does not make the world predictable. It does not eliminate fragility, nor does it provide the total certainty that the symptom demands. It can restore something more genuine: the possibility of living without entrusting one’s entire existence to the impossible quest for a guarantee. It restores time. Choices. Relationships. Actions that become simple again. Little by little, it reclaims the spaces that the disorder had occupied.
Let’s return, then, to the mirror. At first, those who look into it see above all what they fear. A thought becomes a suspicion. A doubt seems to reveal something. An image takes on the force of proof. The reflection no longer matches who one is, because between the eyes and the mirror, the need to constantly question oneself has crept in.
“What if I really were like that?” “What if I couldn’t trust myself?”
“What if that thought actually means something?”
Then, over time, something may change. The thought doesn’t necessarily disappear. The fear doesn’t necessarily subside right away. The mirror is still there. But the way we look at it changes. We learn to recognize that being afraid doesn’t mean we’re in danger. That thinking isn’t the same as wanting. That a possibility isn’t a probability and, above all, isn’t a certainty. That a symptom can speak with a very loud voice without necessarily telling the truth about who we are. Perhaps the heart of the therapeutic journey is precisely this: not to promise someone that they will never doubt again, but to help them not to hand over to doubt the right to decide their life.
Behind obsessive-compulsive disorder, there is no absurd mind. There is often a person exhausted by the attempt to feel definitively safe. Someone who has checked, reconstructed, avoided, sought reassurance, and searched for proof. Someone who, by constantly trying to protect themselves from every possible mistake, has ended up fearing even their own thoughts.
And it is perhaps here that competent, rigorous, and deeply humane treatment can make a difference—not by teaching them to fight their own mind. Not by demanding that they stop being afraid. But by patiently guiding them toward adifferent possibility: inhabiting their inner world without being forced to believe everything that fear projects onto it.
The mirror, in the end, doesn’t change. What changes is the gaze of the person standing before it. And perhaps it is precisely then that doubt, even though it may still make itself felt, finally ceases to have the last word.
