OCD could be a very disabling condition, implying severe impairment of social and occupational functioning and decreased quality of life. OCD is treated with a combination of psychopharmacological treatments and cognitive-behavioural therapy. Clomipramine was the first anti-obsessive drug, and was followed by selective serotonin re-uptake inhibitors (SSRIs), both modulating serotoninergic transmission. Low dose atypical anti-psychotic are sometimes used to potentiate serotoninergic agents. Growing evidence based on animal models and on neuroimaging shows that glutamatergic transmission could play an important role in the aetiology of OCD. Therefore, glutamate modulators such as N-methyl-D-aspartate (NMDA) receptor antagonists became the focus of the search of novel treatments for OCD. One of this drugs, memantine, already approved for Alzheimer disease treatment, was used off-label the first time ten years ago in resistant case of OCD with positive results. Besides some further successful case reports, there are a single-blind case control study and a couple of randomized, double-blind, placebo-controlled trials showing improvement of OCD symptoms with memantine adjuvant pharmacotherapy.

To describe a case report of off-label treatment of a severe resistant case of OCD with memantine, after 15 weeks of treatment.

Literature review and case description. Before beginning treatment with memantine, the patient made a psychological assessement (baseline) with a battery of tests (MINI Plus, Y-BOCS, QPP-15, WDQ, ECPAD, OP2, OAS2, MPS-H&F, MPS-F, HEXACO-PI-R, MOCI, BDI-II). This battery will be repeated after 15 weeks of treatment, to evaluate symptom improvement.

To be announced after 15 weeks of treatment course.

The authors have not supplied their declaration of competing interest.