Remission of Refractory Obsessive–Compulsive Symptoms in an Adolescent with Autism Spectrum Disorder: A Case Report and A Review on Synaptic Plasticity

Emerging work suggests that a fully oral combination of dextromethorphan, a potent CYP2D6 inhibitor, and the AMPA-facilitator piracetam can reproduce key elements of ketamine's rapid, plasticity-enhancing action on cortico-striatal circuits. Published experience in adolescents, however, remains scarce.We report on a 15-year-old boy with autism spectrum disorder, attention-deficit/hyperactivity disorder, and long-standing, severe obsessive–compulsive disorder. Despite good adherence to sodium valproate and risperidone, he continued to exhibit near-continuous rituals, sudden aggression, and social withdrawal. An evening "stack" was introduced that paired fluoxetine 10 mg (for CYP2D6 blockade) with dextromethorphan 30 mg and, two weeks later, piracetam 600 mg. Violent outbursts and time-consuming compulsions subsided within seven days of starting dextromethorphan; school attendance, piano practice, and peer interaction resumed after the addition of piracetam. Symptom remission has been sustained for four months without dose escalation or notable adverse effects.This single case highlights the possible value of inexpensive, repurposed agents aimed at glutamatergic signalling in adolescents whose OCD proves refractory to conventional medication. Targeting synaptic plasticity during a period of heightened developmental pruning may offer a practical route to meaningful functional recovery.