Optimized Oral Glutamatergic Augmentation in Refractory Home-Dominant Contamination Obsessive-Compulsive Disorder With Somatic, Affective, and Motivational Features: A Case Report of Incremental Functional Gains

Cureus. 2026 Jun 26;18(6):e111573. doi: 10.7759/cureus.111573. eCollection 2026 Jun.

ABSTRACT

A proportion of patients with obsessive-compulsive disorder (OCD) continue to experience disabling symptoms despite standard serotonergic treatment, antipsychotic augmentation, and psychological input. Contamination-focused OCD can be especially persistent when rituals are embedded in the home environment and reinforced by family patterns. Recent work has drawn attention to glutamatergic dysfunction, NMDA-AMPA signaling, and synaptic plasticity as possible treatment targets in refractory OCD. The Cheung glutamatergic regimen has been proposed as an oral, low-cost, ketamine-informed glutamatergic strategy using dextromethorphan, CYP2D6 inhibition, piracetam, and L-glutamine to modulate glutamatergic plasticity. The supporting evidence for this proposed regimen remains preliminary, largely case-based, and not independently replicated. A 26-year-old woman presented with several years of contamination fears, repetitive handwashing, prolonged bathing lasting up to 1.5 hours, home-dominant cleaning concerns, anxiety, depressive symptoms, fatigue, somatic complaints, nightmares, and motivational impairment. Baseline screening showed a Patient Health Questionnaire-9 (PHQ-9) of 18 and a Generalized Anxiety Disorder-7 (GAD-7) of 14, with passive suicidal ideation endorsed on one item. Over approximately nine months, treatment was adjusted in routine outpatient care. A glutamatergic-oriented augmentation strategy was used as part of a complex, evolving regimen built around dextromethorphan, piracetam, and later L-glutamine, with pharmacokinetic potentiation via CYP2D6-inhibiting antidepressants, including fluoxetine, bupropion, and later low-dose paroxetine. Low-dose risperidone, clomipramine, pregabalin, propranolol, cyproheptadine, and other symptom-focused adjuncts were used and adjusted according to response and tolerability. Mood, energy, somatic chest discomfort, motivation, and resilience improved. Bathing time decreased from approximately 1.5 hours to about 30 minutes, and ritual preoccupation was at one point described as 20-30% reduced. The PHQ-9 self-harm item changed from “several days” at the first standardized assessment to “not at all” at Day 41, although passive ideation was again endorsed for several days during later stress. She resumed job-seeking, attended interviews, exercised, learned new skills, and coped better than expected with the illness and death of a long-term pet. Residual contamination and cleaning symptoms remained most prominent at home. No Yale-Brown Obsessive Compulsive Scale, formal ritual count, or structured home-versus-outside severity scale was recorded. This case is best read as a hypothesis-generating clinical observation rather than evidence of regimen-specific efficacy. The response was incomplete but clinically meaningful, especially in affective, somatic, motivational, and functional domains. Larger controlled studies are needed, and home-targeted exposure-based work remains essential.

PMID:42368238 | PMC:PMC13308870 | DOI:10.7759/cureus.111573