Memantine for Body-Focused Repetitive Behaviors
Memantine is effective for treating body-focused repetitive behaviors (BFRBs) like trichotillomania and skin-picking disorder in adults who have not responded to habit-reversal therapy, with a number needed to treat of only 1.9 and 60.5% of patients achieving significant improvement at 8 weeks. 1
Evidence Base
The strongest and most recent evidence comes from a 2023 double-blind, placebo-controlled trial specifically examining memantine in 100 adults with trichotillomania or skin-picking disorder 1. This study demonstrated:
- Statistically significant reductions in hair-pulling and skin-picking symptoms compared to placebo
- 60.5% of memantine-treated patients were "much or very much improved" at 8 weeks versus only 8.3% on placebo
- Number needed to treat of 1.9 - exceptionally high efficacy
- Significant improvements in disability scores and overall clinical severity
- Well-tolerated with no significant difference in adverse events between memantine and placebo groups
Dosing Strategy
Based on the trial evidence 1:
- Dosing range: 10-20 mg/day
- Duration: 8 weeks minimum to assess response
- Start at lower doses and titrate based on tolerability
Context Within Treatment Guidelines
While memantine is FDA-approved only for Alzheimer's dementia 2, the glutamatergic system has emerged as a therapeutic target for compulsive behaviors. OCD treatment guidelines mention memantine as an augmentation option for treatment-resistant cases, noting that "several trials have demonstrated its efficacy in SSRI augmentation for patients with treatment-resistant OCD" 3. BFRBs share neurobiological overlap with OCD as obsessive-compulsive related disorders 3.
Clinical Algorithm
For adults with BFRBs who have failed habit-reversal training:
Confirm adequate trial of habit-reversal therapy - The evidence shows most patients never receive proper evidence-based treatment, with only 13.5% seeking professional help and approximately 40% of those receiving no evidence-based advice 4
Consider memantine as next-line treatment given the robust efficacy data specifically in this population 1
Initiate at 10 mg/day, titrate to 20 mg/day as tolerated over 1-2 weeks
Assess response at 8 weeks using standardized measures of pulling/picking severity
Continue if beneficial - the trial showed sustained improvements, and memantine's mechanism as an NMDA receptor antagonist targeting glutamatergic dysregulation provides biological plausibility 1
Important Caveats
- Renal dosing required: Reduce to 5 mg twice daily in severe renal impairment (CrCl 5-29 mL/min) 2
- Caution in severe hepatic impairment 2
- Monitor for rare serious adverse events including Stevens-Johnson syndrome, though these are exceedingly uncommon 2
- The FDA label does not include BFRBs as an indication, so this represents off-label use 2
Comparison to Other Evidence
The memantine evidence for BFRBs 1 is actually stronger and more direct than the evidence for memantine in OCD, where recent meta-analyses show conflicting results. One 2026 meta-analysis found no statistically significant benefit overall (mean difference -3.74 points, 95% CI -9.95 to 2.47) with high heterogeneity 5, while another concluded memantine "may offer therapeutic benefits" but cited significant methodological limitations 6. The BFRB trial stands out for its methodological rigor, specific population, and remarkably high effect size.
Bottom Line
Memantine represents an evidence-based pharmacological option for adults with trichotillomania or skin-picking disorder who have not responded to habit-reversal therapy, with exceptional efficacy (NNT=1.9) and good tolerability. This recommendation prioritizes the single highest-quality, most recent study directly addressing the clinical question 1, which demonstrates clear benefits in morbidity (symptom reduction) and quality of life (disability improvement).