Differential Improvement in Obsessive Rumination and Fantasy Intrusions Versus Attachment-Related Emotional Dysregulation During Oral Glutamatergic Augmentation in a 16-Year-Old Adolescent.

A 16-year-old post-pubertal female presented with mixed anxiety-depressive symptoms, prominent obsessive rumination, relationship-centered guilt, reassurance-seeking, fantasy intrusions, and difficulty separating fantasy from reality during periods of distress. Baseline scores were in the moderate range for depression and severe range for anxiety, with a Patient Health Questionnaire-9 score of 14 and a Generalized Anxiety Disorder-7 score of 20. A low-to-moderate-intensity Cheung glutamatergic regimen-like strategy was introduced, consisting of dextromethorphan, a CYP2D6-inhibiting antidepressant, and piracetam, with risperidone co-prescribed for fantasy-related cognitions, overvalued ideas, and obsessive instability. Across the follow-up period from January to June 2026, depressive symptoms improved to the minimal-to-mild range, and anxiety symptoms improved to the mild range, with Patient Health Questionnaire-9 scores mostly between 4 and 6 and Generalized Anxiety Disorder-7 scores mostly between 6 and 7, except for one stress-related rise to 11. Obsessional symptoms reportedly reduced by more than 30% after dextromethorphan escalation and piracetam introduction. Later improvements included better ability to interrupt rumination, reduced preoccupation with "pretending to be ill," shorter fantasy intrusions, and improved fantasy-reality differentiation. No medication side effects, dissociation, hypomania, serotonin-toxicity symptoms, sleep disruption, appetite loss, or renewed self-harm ideation were documented. The clinically distinctive feature was a discordant response pattern as follows: repetitive, obsessive, and fantasy-related intrusions appeared to loosen more clearly than attachment-linked emotional reactivity. The course is compatible with the hypothesis that N-methyl-D-aspartate and α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (NMDA-AMPA) modulation may help selected post-pubertal adolescents disengage from rigid perseverative loops. However, interpretation is limited by polypharmacy, risperidone titration, selective serotonin reuptake inhibitor (SSRI) effects, supportive care, natural symptom fluctuation, and the absence of formal obsessive-compulsive ratings or withdrawal/rechallenge. This case is best viewed as hypothesis-generating.