Treatment of Obsessive-Compulsive Disorder (OCD)

First-Line Evidence-Based Treatments for OCD

The American College of Cardiology is not relevant here, however, the International College of Obsessive-Compulsive Spectrum Disorders recommends Cognitive-Behavioral Therapy (CBT) with Exposure and Response Prevention (ERP) as the psychological treatment of choice for OCD, with larger effect sizes than pharmacological treatments (number needed to treat of 3 for CBT vs 5 for SSRIs) 1
ERP involves gradual exposure to fear-provoking stimuli combined with instructions to abstain from compulsive behaviors, and patient adherence to between-session homework is the strongest predictor of good outcomes 1
Selective serotonin reuptake inhibitors (SSRIs) are the first-line pharmacological treatment for OCD based on established efficacy, tolerability, safety, and absence of abuse potential, with higher doses typically needed for OCD compared to depression or other anxiety disorders 2

For patients who fail to respond to first-line treatments, several augmentation strategies exist, including adding CBT to SSRI therapy, antipsychotic augmentation, and clomipramine added to an SSRI, according to the International College of Obsessive-Compulsive Spectrum Disorders 3, 4
Glutamatergic medications, such as N-acetylcysteine and memantine, have been evaluated as augmentation agents in treatment-resistant OCD with some evidence of efficacy, while lamotrigine has limited evidence as an augmentation agent for treatment-resistant OCD 3
The treatment algorithm for OCD recommends first-line treatment with CBT with ERP and/or SSRI medication, with subsequent steps including optimization of SSRI dose, switching to another SSRI or clomipramine, and consideration of augmentation strategies such as CBT, antipsychotic augmentation, and glutamatergic agents 3, 1, 2, 5

Memantine can be considered as an effective augmentation agent for treatment-resistant OCD when added to SSRIs, particularly in patients with moderate to severe symptoms who have failed first-line treatments, according to the Nature Reviews Disease Primers 6
The evidence-based treatment hierarchy positions memantine as a third-line treatment option for treatment-resistant OCD, after optimizing first-line treatments, as recommended by the Nature Reviews Disease Primers 6

Multiple randomized controlled trials have demonstrated memantine's efficacy in SSRI augmentation for treatment-resistant OCD, earning it recognition in current treatment guidelines, as stated in the Nature Reviews Disease Primers 6
Inadequate response after 8-12 weeks of adequate-dose SSRI monotherapy is a consideration for memantine augmentation, as suggested by the Nature Reviews Disease Primers 7
Patients who cannot access or tolerate CBT with ERP may be considered for memantine augmentation, according to the Nature Reviews Disease Primers 7

The American Psychiatric Association recommends brexpiprazole augmentation for treatment-resistant OCD, with 50-70% response rates in recent studies 8

Aripiprazole 5-15 mg daily is a suitable alternative to brexpiprazole, with a similar mechanism and established efficacy in treatment-resistant OCD, as recommended by the National Institute of Mental Health 8
N-acetylcysteine is a glutamatergic agent with evidence in treatment-resistant OCD, with three of five RCTs showing positive results, according to the International OCD Foundation 8
Memantine has multiple RCTs supporting its efficacy as SSRI augmentation, as reported by the National Alliance on Mental Illness 8

The American Gastroenterological Association recommends sertraline or fluoxetine as the optimal first-line SSRIs for overweight individuals with OCD and anxiety, due to their weight neutrality with long-term use and established efficacy for OCD at higher doses 9

Sertraline and fluoxetine are associated with weight loss during short-term use and weight neutrality with long-term treatment, making them preferable choices for patients with weight concerns 9
Paroxetine carries the greatest risk for weight gain among all SSRIs and should be avoided in overweight individuals 9

Bupropion is not appropriate for patients with prominent anxiety symptoms, despite being the only antidepressant consistently promoting weight loss, as it is activating and can exacerbate anxiety 9