University of Texas Southwestern Medical Center researchers are studying the possibility of using the drug memantine, typically prescribed for severe Alzheimer’s patients, for treating treatment-resistant depression. The ongoing research is providing clues for how to develop of rapid-acting antidepressants, in order to replace the often addictive drugs currently prescribed.
Currently, the researchers are comparing the action of memantine with the action of ketamine, since both drugs block the brain’s NMDA receptors, and may elicit rapid antidepressant effects in patients with resistance to treatment. However, ketamine, also known as the party drug “Special K,” is as anesthetic that produces several side effects, including hallucinations, and is addictive.
However, according to Dr. Lisa Monteggia, professor of Neuroscience and holder of the Ginny and John Eulich Professorship in Autism Spectrum Disorders, one of the important discoveries of the study is that memantine doesn’t act as fast as ketamine: “Although, both ketamine and memantine have similar actions when nerve cells are active, under resting conditions, memantine is less effective in blocking nerve cell communication compared to ketamine. This fundamental difference in their action could explain why memantine has not been effective as a rapid antidepressant.”
Indeed, the UT Southwestern researchers were able to observe that the two drugs emanate different signals from the NMDA receptors, particularly concerning their antidepressant efficacy.
The study will now redirect attention to the molecular and cellular bases of neural plasticity, which is one of the main properties of nerve cells capable of altering their communication. To this point, the main goal is to increase knowledge about the mechanisms underlying antidepressant efficacy and neuropsychiatric disorders.
Last March, The University of Texas Health Science Center at Houston (UTHealth) also announced a pilot study, in collaboration with researchers from the University Hospital Bonn, in Germany, to assess the use of deep brain stimulation (DBS) in the medial forebrain bundle of the brain, as an alternative therapy for treatment-resistant depression.
The American Psychiatric Association recommends medication as the preferred course of treatment for severe depressive symptomatology. Antidepressants were the third most common prescription drug in the U.S., between 2005 and 2008, and around one in 10 people 12 years old or older takes anti-depressant drugs, 14 percent of which have taken them for over 10 years.
Nearly 8 percent of Americans over the age of 12 are reported to suffer from depression, and women are the most susceptible gender. Women are two and a half times more likely to take antidepressant medication as men, and 23 percent of women aged 40 to 59 take antidepressants. More than 8 million visits to physician offices, hospital outpatient, and emergency departments are caused by depression.