Is memantine (N-methyl-D-aspartate receptor antagonist) effective for treating skin picking or other compulsive body repetitive behaviors, such as trichotillomania or excoriation disorder?

Memantine for Skin Picking and Body-Focused Repetitive Behaviors

Memantine is highly effective for treating skin picking disorder (excoriation disorder) and trichotillomania, with a number needed to treat of only 1.9, making it one of the most efficacious pharmacological interventions available for these conditions. 1

Evidence for Memantine Efficacy

The strongest evidence comes from a 2023 double-blind, placebo-controlled trial of 100 adults with trichotillomania or skin-picking disorder, which demonstrated that 60.5% of participants receiving memantine were "much or very much improved" compared to only 8.3% in the placebo group 1. This represents exceptional efficacy for body-focused repetitive behaviors, which have historically been difficult to treat pharmacologically.

• Memantine dosing ranged from 10-20 mg/day over 8 weeks, with significant improvements on multiple outcome measures including the NIMH Trichotillomania Symptom Severity Scale, Sheehan Disability Scale, and Clinical Global Impressions severity scale 1
• The medication was well-tolerated with adverse events not differing significantly from placebo 1
• The glutamate system appears to be a beneficial target for treating compulsive behaviors 1

Treatment Algorithm

First-line treatment should be cognitive-behavioral therapy (CBT) with habit reversal training, incorporating awareness training, development of competing responses, and self-monitoring tools 2. CBT-based approaches including acceptance and commitment therapy-enhanced group behavioral therapy, online self-help modules, and expressive writing have demonstrated the best nonpharmacological results 3.

Memantine should be considered as second-line pharmacological treatment when CBT is insufficient, unavailable, or not tolerated 2. This represents a departure from traditional OCD treatment hierarchies where memantine is positioned as third-line 4, 5, because the direct evidence for skin picking disorder is substantially stronger than for OCD.

N-acetylcysteine (1200-2400 mg/day in divided doses) is an alternative glutamatergic agent with established efficacy and minimal side effects 2, though the evidence for memantine in skin picking disorder specifically is more robust based on the 2023 trial 1.

Practical Implementation

• Start memantine at 5 mg daily and titrate to 10-20 mg/day over 2-4 weeks to minimize side effects
• Treatment duration should be at least 8 weeks to assess response 1
• Memantine can be used as monotherapy or combined with CBT for enhanced outcomes 2, 6
• Family involvement is recommended, particularly for younger patients, to provide support and reinforce behavioral strategies 2

Critical Distinction from Body Dysmorphic Disorder

It is essential to differentiate skin picking disorder from skin picking in body dysmorphic disorder (BDD), as the underlying motivations differ fundamentally 7. In excoriation disorder, picking is not primarily driven by attempts to improve appearance of perceived defects, whereas in BDD, picking is specifically intended to correct perceived appearance flaws 7. This distinction affects treatment approach, as BDD requires different interventions targeting the appearance preoccupation itself.

Broader Application to Body-Focused Repetitive Behaviors

The 2023 trial included both trichotillomania (hair pulling) and skin picking disorder, demonstrating memantine's efficacy across body-focused repetitive behaviors 1. A systematic review confirms memantine's therapeutic potential extends to multiple psychiatric conditions involving compulsive behaviors, including OCD, where it has been used successfully as both augmentation and standalone therapy 8.

Memantine augmentation has been validated in multiple randomized controlled trials for treatment-resistant OCD, with meta-analysis showing a mean reduction of 11.73 points in Y-BOCS scores and patients being 3.61 times more likely to respond compared to placebo 9. This broader evidence base supports memantine's mechanism of action through glutamate modulation being relevant to compulsive behaviors generally 7, 5.

Safety Profile and Monitoring

Memantine demonstrates excellent tolerability with no significant difference in adverse events compared to placebo in the skin picking disorder trial 1. Regular monitoring should assess:

• Reduction in picking/pulling frequency and severity using validated scales
• Functional impairment using the Sheehan Disability Scale 1
• Risk of self-harm, infection, scarring, and tissue damage, as approximately half of young people with body-focused repetitive behaviors report self-harm 2