Memantine as an Augmenting Agent for Severe Pediatric OCD

A 15-year-old girl presented with severe OCD characterized by prominent mental rituals in addition to aggressive, contamination, and somatic obsessions as well as repeating, superstitious, and checking rituals. The patient experienced onset of OCD symptoms between the ages of 4 and 5 years. Her symptoms became impairing, and she met OCD diagnostic criteria between the ages of 10 and 11 years. Her OCD treatment history included years of cognitive behavioral therapy (CBT) with an experienced psychologist and pharmacological trials with sertraline and fluvoxamine treatment, both of which were discontinued as a result of an agitation side effect. Initiating treatment with citalopram and increasing the dose to 80 mg/day for 10 weeks did not result in symptom improvement. The patient was hesitant to initiate a clomipramine or antipsychotic treatment trial, given potential cardiac and weight gain side effects, respectively. As a result of her extremely severe symptoms (Children’s Yale-Brown Obsessive Compulsive Scale score=36/40), the off-label use of memantine augmentation as well as the drug’s risks and benefits were discussed with the patient, and she and her mother provided informed consent. Memantine, 5 mg/day, was initiated, while her citalopram dose and CBT parameters remained unchanged. Subsequently, the patient’s mother and psychologist reported her increasingly debilitating OCD symptoms. At day 10, this decline dramatically shifted, and she successfully resisted obsessions and controlled rituals for the first time since her OCD onset. Memantine was increased to a final dose, 5 mg b.i.d., without reported side effects. One month after memantine initiation, the patient revealed only mild to subclinical symptoms (Children’s Yale-Brown Obsessive Compulsive Scale score=6). No subsequent medication or treatment changes were made.

The patient is presently in month 9 of memantine augmentation, with no evidence of OCD relapse or medication intolerance. Her reported obsessions last less than 1 hour daily, with low intensity and distress and increased ability to resist and control them. Her last reported compulsion occurred on day 10 of the memantine trial. Of interest, the patient attributes success to her emergent ability to resist obsessions and engage in CBT response prevention strategies.