When thoughts take control... OCD explained

Francis Merson Clinical Psychologist

Obsessive Compulsive Disorder (OCD) rarely arrives in the therapy room by announcing itself clearly... Most people who eventually receive an OCD diagnosis do not come to therapy saying “I think I have OCD.” They come saying things like “I can’t switch my brain off,” “I don’t trust my own judgment,” or “I feel constantly on edge.” I've seen many people who have been living with OCD for years without knowing it. They often assume they are just anxious, perfectionistic, overly cautious or bad at letting things go. By the time they reach therapy, they are usually exhausted. Not just by the anxiety itself, but by the constant mental effort of managing it. OCD can quietly take over mental space, time and energy. It interferes with work, relationships, and everyday decisions. Because much of OCD happens internally, it is often invisible to others. People can look like they are coping with life, while feeling completely stuck inside their own head. The good news is that OCD is one of the most treatable mental health conditions. With the right therapeutic approach, it is possible to reduce the intensity of obsessive thoughts, loosen the grip of compulsive behaviours and regain a sense of trust in yourself and your own mind.

What is Obsessive Compulsive Disorder (OCD)?

OCD is built around a loop between obsessions and compulsions, but those words don't generally mean what people think they mean.

Obsessions are intrusive thoughts, images, or doubts that feel unwanted and distressing. People often say, “I know this doesn’t make sense, but I can’t let it go.” The content varies, from harm and responsibility to contamination or morality, but what matters most is how sticky the thought becomes. It does not pass through the mind. It demands a response.

Compulsions are the responses that follow. They are anything done to reduce the anxiety created by the obsession. Sometimes they are visible, like checking, washing or rereading messages. Often they are internal, such as mentally replaying conversations, seeking reassurance, googling symptoms or trying to feel certain before moving on.

What This Actually Looks Like

In practice, this can look very different from common stereotypes. One client might check emails repeatedly out of fear of having offended someone. Another, a parent, could be distressed by intrusive thoughts about harm and spent hours mentally checking whether they were a safe person. Others have found themselves unable to leave the house without repeated checks, or replaying social interactions late into the night searching for certainty.

The compulsion brings brief relief, but it strengthens the disorder. Each time anxiety drops after a check or mental review, the brain learns that the ritual was necessary. Over time, more certainty is required and the cycle tightens.

"Exposure is often misunderstood as throwing someone in the deep end on day one of therapy"

Which Kinds of Therapy Can Actually Help? Effective therapy for OCD is not about convincing you that your fears are irrational or trying to eliminate intrusive thoughts altogether. That approach often backfires.

At the Paris Psychology Centre, we use evidence-based approaches, and there are three main modalities that have been shown to be the most effective in the clinical research.

Exposure and Response Prevention (ERP)

ERP is generally considered the gold-standard treatment for OCD, but exposure is often misunderstood as meaning throwing someone in the deep end on day one of therapy. And that misunderstanding can scare people away from exposure before they even begin.

It's worth emphasising that ERP works by very gently and gradually helping you face the situations, thoughts, or sensations that trigger anxiety, without engaging in the usual compulsive response. Over time, the brain learns something crucial: that anxiety rises and falls on its own, and you don't need to do anything about it.

For example, someone with checking-related OCD might practise leaving the house after one check rather than five. Someone with intrusive thoughts might practise allowing the thought to be present without analysing or neutralising it. These are small steps, but they retrain the nervous system in a powerful way.

Cognitive Behavioural Therapy (CBT)

CBT helps identify the beliefs that keep OCD going. In people with OCD these most often include an exaggerated sense of responsibility, intolerance of uncertainty, or the belief that having a thought means something about who you are. In therapy, we work collaboratively to examine these beliefs, test them in real life, and develop more flexible ways of responding to uncertainty and discomfort.

Acceptance and Commitment Therapy (ACT)

ACT is a newer therapy based around mindfulness, which adds an important layer, especially for people who feel trapped in constant mental struggle. Rather than fighting thoughts or trying to win against anxiety, ACT focuses on learning to make space for internal experiences while still living in line with what matters to you.

For many people with OCD, this shift is relieving. In therapy I've seen the goalposts in people's minds move from “I need to feel certain or calm before I live my life” to “I can live my life even when my mind is loud.”

Taking the First Steps Toward Recovery Recovery from OCD does not mean never having intrusive thoughts again. It means those thoughts lose their power. They come and go without dictating behaviour, mood, or self-worth.

Clients often describe feeling more grounded, less reactive, and more trusting of themselves. Decisions become easier, and anxiety no longer runs the show. Success isn't instantaneous, and therapy requires patience, consistency, and support. But meaningful change is absolutely possible. If you recognise yourself in any of this, you are not alone and you do not have to figure it out by yourself. At the Paris Psychology Centre, our clinicians have extensive experience working with OCD in all its forms. We work at your pace, using approaches that are both compassionate and evidence-based.