An Unlikely Pairing: Can an Alzheimer's Drug Help Your BFRB?

Memantine is a medication that has been explored as a potential treatment for a number of psychiatric and neurological conditions with varying success rates. While it is primarily used to manage symptoms of Alzheimer's disease (it is thought to slow down the cognitive decline), it has also been investigated for its potential efficacy in treating hair pulling and skin picking!

For those who are learning about body-focused repetitive behaviors just now, trichotillomania is characterized by the repetitive urge to pull out one's hair, leading to noticeable hair loss and significant distress or impairment in daily functioning. The exact causes of trichotillomania are not fully understood, but it is believed to involve a combination of genetic, environmental, and neurobiological factors – in other words, a mishmash of various complex factors. The same goes for skin picking, only instead of pulling their hair, people who struggle with skin picking pick their skin, causing infections and even permanent scarring.

Research on the use of memantine for trichotillomania and dermatillomania is severely limited but has shown some promising results. A study published this year (2023) and conducted at the University of Chicago, headed by the famous and ubiquitous (in this field at least) Dr. Grant, found the following:

Compared with placebo, memantine treatment was associated with significant improvements in scores on the NIMH scale, Sheehan Disability Scale, and Clinical Global Impressions severity scale in terms of treatment-by-time interactions. At study endpoint, 60.5% of participants in the memantine group were "much or very much improved," compared with 8.3% in the placebo group (number needed to treat=1.9). Adverse events did not differ significantly between the treatment arms.

OK, but, Vladimir, what is this memantine thing?

Memantine is a medication that works by modulating the activity of a neurotransmitter called glutamate in the brain. Glutamate is likely the most abundant excitatory neurotransmitter in the brain and plays a crucial role in communication between neurons. You may be rolling your eyes now, wondering what the heck an excitatory neurotransmitter is. Excitatory neurotransmitters promote the activation and firing of neurons, resulting in an increase in neuronal activity. They play a vital role in various cognitive functions, sensory perception, motor control, and overall brain activity.

Glutamate, to the best of our knowledge, plays a role in processes such as learning, memory, and cognition. Prepare yourself for some more fancy medical words. Memantine acts as a selective, non-competitive antagonist of NMDA receptors; does that sound profound or what?! NMDA receptors are important for synaptic plasticity and learning, but overactivation of these receptors can lead to toxic effects and neuronal damage. To put it simply, you need glutamate but not too much and there’s a balance that needs to be found.

By antagonizing NMDA receptors, memantine helps regulate glutamate activity by blocking excessive stimulation while still allowing normal glutamate signaling. In other words, at least theoretically, It modulates the receptor's activity. In fact, it appears to preferentially targets receptors that are excessively activated, while sparing those that are normally functioning.

The specific effects of memantine can vary depending on the brain region and neuronal context. By restoring balance to glutamate signaling, memantine aims to protect neurons from excessive excitotoxicity and improve overall brain function. It is thought that abnormalities in glutamate signaling may contribute to the development and maintenance of trichotillomania symptoms.

A small number of studies have explored the effects of memantine in individuals with trichotillomania and skin picking. These studies have generally reported a reduction in hair pulling symptoms and improvements in overall functioning. For example, a study published in the Journal of Clinical Psychopharmacology in 2012 found that memantine led to significant reductions in hair pulling behaviors and improved quality of life in a group of individuals with trichotillomania.

Despite these positive findings, it is important to note that the research on memantine for trichotillomania is limited, and larger, well-controlled studies are needed to establish its effectiveness and determine optimal dosing. I always add this caveat when I present research results because studies involve small sample sizes, often have methodological difficulties, etc. Additionally, individual responses to medication can vary, and not all individuals with BFRBs may benefit from memantine. I always say that even though hair pulling or skin picking involve a specific symptom, that symptom is many different thing because it is a part of an infinite number of different lived experiences.

But… why memantine?

The idea to test memantine for hair pulling and skin picking likely came from several factors, including our current and admittedly limited understanding of the underlying neurobiology of the condition and the known effects of memantine on the brain.

Researchers have been investigating the neurobiological basis of trichotillomania and dermatillomania to gain insights into potential treatment targets. Even though some interesting findings have emerged, we truly don’t have a biological model of BFRBs – nor a complete psychological one. Those who are inclined to think in biological terms, believe that imbalances in the neurotransmitter systems, such as glutamate and dopamine, may play a role in the development and maintenance of BFRBs. If you’re a constructivist like me, you’ll take what works for a specific person and run with it.

Memantine is an NMDA receptor antagonist, meaning it modulates the activity of glutamate, a major excitatory neurotransmitter in the brain. Alterations in glutamate signaling have been implicated in various psychiatric conditions, including obsessive-compulsive disorder (OCD) and related disorders like trichotillomania or dermatillomania. This isn’t a firm scientific argument, but it’s certainly an enticing parallel worth investigating. BFRBs are often considered part of the obsessive-compulsive and related disorders category. Since memantine has shown some efficacy in reducing symptoms of OCD, researchers may have speculated that it could potentially be helpful for trichotillomania as well.

These factors likely led researchers to hypothesize that memantine, with its mechanism of action targeting glutamate receptors, might be beneficial in reducing the symptoms of trichotillomania. While memantine has a long way to go to be approved for BFRB treatment, the little evidence we have now seems promising and certainly worth exploring further.