I was lucky enough to attend the ORCHARD OCD international scientific conference at the start of June in London. This conference was filled with the latest cutting edge discoveries and research in the world of OCD. The atmosphere in the room was incredible- experts from around the world all working towards a common goal- to effectively treat all sub-types and severities of OCD.
At the end the 2nd day of the conference, the new international treatment guidelines (CANMAT ICOCS Guidelines for Treatment of OCD) were unveiled by Prof. Dr. Michael van Ameringen. This was a pretty big deal.
This is my take on the guidelines- none of this is intended to read as fact- I am not a medical doctor and it is my understanding as an OCD CBT therapist. If you are interested in reading the full paper then it is available here:
What stood out to me in the new international OCD treatment guidelines
As a CBT therapist, I’m always interested when new treatment guidelines are published. Not because I expect them to revolutionise practice overnight, but because they offer an opportunity to see where the evidence is moving and whether that aligns with what we’re seeing clinically.
Having read the new guidelines, what struck me most wasn’t a dramatic new intervention. Instead, it was the clarity around treatment sequencing, the continued emphasis on CBT with Exposure and Response Prevention (ERP), and the realistic approach taken towards medication management.
CBT with ERP remains central
One of the clearest messages throughout the guidelines is that CBT incorporating ERP remains a first-line treatment for OCD.
This isn’t particularly surprising. Decades of research have demonstrated that ERP is one of the most effective interventions we have for OCD. What I found interesting, however, was the extent to which the guidelines continue to position ERP at the centre of treatment, even as newer biological and neuromodulation approaches emerge.
This serves as an important reminder that not all CBT is OCD-specific CBT. The guidelines repeatedly distinguish between general CBT approaches and CBT that includes structured ERP. Simply discussing intrusive thoughts, challenging cognitions, or teaching anxiety-management techniques is not the same as helping someone systematically approach feared situations whilst resisting compulsions.
In practice, this distinction matters. Many people referred for OCD report having had previous therapy that helped them understand their thoughts but did little to change their relationship with them.
The evidence continues to suggest that behavioural change remains a critical component of successful treatment. At the conference, there was also discussion of emerging neuroimaging findings highlighting that some of the most notable changes in brain structure and function are associated with the repeated engagement in OCD-related behaviours over time. In other words, responding to intrusive thoughts with compulsions appears to reinforce patterns of neural activation that can, in some cases, be observed on brain imaging.
From a CBT perspective, this reinforces the importance of targeting behaviour directly. By focusing on high-quality CBT for OCD, particularly Exposure and Response Prevention, and supporting changes in how individuals respond to intrusive thoughts, we are not only reducing symptoms at a psychological level but also potentially influencing the underlying neural patterns that maintain the disorder.
The guidelines endorse shared decision-making
One aspect of the treatment pathway I appreciated was the emphasis on shared decision-making. Rather than presenting a rigid hierarchy, the guidelines acknowledge that some individuals will prefer psychological treatment, whilst others may opt for medication or a combination of both.
For mild to moderate OCD, either CBT with ERP or an SSRI may be offered as a first-line intervention.
However, for individuals with more severe symptoms, greater functional impairment, or where a single treatment has proven insufficient, the guidelines increasingly favour combined treatment involving both ERP and medication.
This feels clinically sensible. While many people improve with either treatment alone, severe OCD often benefits from a multi-modal approach.
Medication: adding clarity
Another point emphasised throughout the guidelines is that OCD medication treatment differs from depression treatment.
SSRIs remain the recommended first-line medications, but the guidelines highlight several realities that patients are often not told:
- Higher doses are frequently required (titrating to the maximally tolerated dose).
- Improvement often takes longer to emerge.
- Adequate treatment trials may need to continue for 12 weeks or longer.
- Partial improvement is common before substantial improvement occurs.
This has important implications for clinical practice.
I frequently meet clients who have concluded that medication “didn’t work” when, according to guideline standards, they may never have received an adequate dose or a long enough trial.
The guidelines therefore encourage optimisation of SSRI treatment before moving on to more complex interventions. It also suggests that for those who have responded to an SSRI and are tolerating it well, continuing the treatment for at least 12 months and possibly indefinitely to prevent relapse.
What happens when first-line treatment doesn’t work: Augmentation and specialist interventions
Where symptoms remain severe despite appropriate first-line treatment, the pathway becomes increasingly specialised.
The guidelines support antipsychotic augmentation for selected individuals who have not responded adequately to SSRIs. This does not mean that OCD is considered a psychotic disorder. Rather, a small number of antipsychotic medications have been shown to enhance the effects of SSRIs in some treatment-resistant cases.
The strongest evidence remains for low-dose antipsychotic augmentation, particularly with risperidone, whilst aripiprazole is also supported by a growing evidence base. These medications are typically added to an existing SSRI rather than prescribed alone and are generally considered only after an adequate SSRI trial has been completed.
As with all medication decisions, the potential benefits must be weighed against possible side effects, including weight gain, metabolic changes, movement-related side effects, and sedation. For this reason, the guidelines recommend careful monitoring and specialist oversight when these medications are used.
The guidelines also discuss emerging augmentation approaches that target neurotransmitter systems beyond serotonin. In particular, there is increasing interest in glutamate-modulating treatments, reflecting evidence that glutamatergic dysfunction may contribute to OCD symptoms.
Memantine, originally developed for Alzheimer’s disease, is one of the mentioned medications. When added to an SSRI, it has shown promising results in some individuals with treatment-resistant OCD. Other drugs discussed within the wider evidence base include lamotrigine, topiramate and N-acetylcysteine (NAC), although the evidence remains less robust than for established first-line treatments.
For a smaller group of patients with severe and enduring OCD, neuromodulation approaches such as repetitive Transcranial Magnetic Stimulation (rTMS) and Deep Brain Stimulation (DBS) are discussed.
My understanding is that TMS works by using focused magnetic pulses to modulate activity in specific brain circuits involved in OCD, particularly those linked to cognitive control, threat monitoring, and habit formation. The goal is not to “erase” symptoms, but to alter the functioning of neural networks that may be overactive or dysregulated in OCD.
Clinically, studies have shown that some individuals experience a meaningful reduction in symptom severity following a course of rTMS, particularly when targeted to regions such as the supplementary motor area or dorsolateral prefrontal cortex. Improvements tend to be gradual rather than immediate, and are often most effective when TMS is delivered alongside ongoing psychological treatment rather than in isolation.
TMS represents a promising development in the field of OCD treatment, particularly for those who have struggled to respond to standard interventions, but it seems to remain an adjunct rather than a replacement for established first-line therapies such as CBT with ERP.
My Overall Impression
If I had to summarise the guidelines in one sentence, it would be this: they reinforce the importance of getting the basics right before assuming treatment has failed.
The document repeatedly returns to the same principles—accurate diagnosis, high-quality ERP, appropriately managed medication, and sufficient treatment duration.
It also gives hope- there are lots of treatment options available if CBT, or SSRI’s or CBT+SSRI’s have not worked.
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