After eight weeks, 26 of the 43 study participants taking memantine had much improvement or very much improvement, compared to three of the 36 taking a placebo.

The Alzheimer’s disease memantine effectively reduces symptoms of adults with trichotillomania and skin-picking disorder also known as excoriation disorder, new research shows.

Researchers honed in on memantine based on earlier findings that revealed disorganized areas of white matter in certain parts of the brain controlling motor habits in individuals with either disorder.

The findings suggested involvement of the neurotransmitter glutamate, a leading theory of the neurobiology behind obsessive-compulsive disorder, says lead author Jon Grant, MD, professor of psychiatry and behavioral neuroscience at the University of Chicago Medicine, in a news release.

When it comes to drugs, “we don’t have a lot of options about what might modulate glutamate in the brain,” he says.

Grant selected memantine, which is approved to address memory loss and deficits in thinking in people with Alzheimer’s disease and has been used off-label for various psychiatric disorders. It is well-tolerated by patients and has few serious side effects, he says.

While Grant was investigating memantine for trichotillomania and skin-picking disorder, another patient of his was prescribed the drug for a separate reason.

“It came kind of serendipitously,” he shares. “One day the patient told me, ‘Wow, that stopped me from pulling my hair.’”

The new study involved 100 adults with trichotillomania or skin-picking disorder who were enrolled in the double-blind trial of memantine or a placebo for eight weeks.

Researchers assessed patients every two weeks using the National Institute of Mental Health Trichotillomania Symptom Severity Scale, which they modified for skin-picking, because there is no commonly used measurement for the disorder.

They also recorded changes using four other self-reported and clinician-observed accounts of symptoms and behaviors. Patients were seen virtually because of the COVID-19 pandemic.

Seventy-nine participants completed the study. Two dropped out after reporting dizziness while taking the medication.

After eight weeks, 26 of the 43 study participants taking memantine had much improvement or very much improvement, compared to three of the 36 taking a placebo. Six people in the memantine group and one in the placebo group had complete relief of symptoms.

An analysis found that memantine is more effective than other treatments studied thus far, including behavioral therapy, the drug olanzapine (used to treat schizophrenia and bipolar disorder), the drug clomipramine (used to treat obsessive-compulsive disorder), and N-acetylcysteine (an over-the-counter supplement).

The comparisons suggest that memantine might be considered a first-line treatment equal to behavioral therapy in the treatment process for these conditions, according to the study.

Grant says the results point to several additional areas for research, including combining memantine with behavioral therapy or with N-acetylcysteine, which showed promise in previous studies led by Grant. Longer-term use of memantine and different doses also are potential avenues for study, he says.

“The results did show that the medication helped more than the placebo, for which I was very pleased, but it tells me that there's still a lot more to do," Grant says. "Even though the results were promising, it was still a very small minority of people in terms of complete remission of symptoms.”

Still, some study participants indicated they intended to seek memantine prescriptions from their primary physicians to continue on the drug, Grant said.

“Some people came in thinking, ‘Nothing has been able to help me.’ Some of them were seeing by the end that this one is different,” he says.