A study by researchers at UCLA has found a new, noninvasive way to predict which individuals will respond favorably to the most commonly used medications to treat depression: brain-wave recordings.
Depression is a major public-health problem and leading cause of disability that affects 17-million people in the U.S. every year. Fewer than one-third of people with the disorder find relief from depression with the first antidepressant that is prescribed for them — and patients must wait weeks-to-months to see if the antidepressant will be effective. Some people also stop taking antidepressants because of the medications’ side effects.
Researchers at the Jane and Terry Semel Institute for Neuroscience and Human Behavior at UCLA report that a simple biomarker — a pair of brain-wave recordings, or electroencephalograms, that can be performed in a doctor’s office in about 10 minutes — can predict if the person will enter remission after just one week. “Knowing whether or not a medication is going to work could eliminate weeks of waiting by the patient and get them on effective treatment more quickly,” says Andrew Leuchter, MD (RES ’84, FEL ’86), professor of psychiatry and biobehavioral sciences.
The researchers used the electroencephalogram recordings to predict recovery from depression in those taking escitalopram, a common antidepressant sold under the brand name Lexapro. Escitalopram works by increasing the levels of serotonin, a chemical messenger or neurotransmitter in the brain that helps to regulate mood. Serotonin levels in the brain also maintain the ratio between slow brain waves (so-called delta–theta activity) and faster “alpha” brain waves. The brain uses this ratio between fast and slow waves to form chemical or electrical networks that support normal mood and thinking.
Dr. Leuchter, who also is director of the Semel Institute’s Neuromodulation Division, and his colleagues reasoned that the effect of escitalopram in shifting the balance between delta-theta and alpha activity would predict the effectiveness of the drug in relieving symptoms of depression. The researchers tested if brain-wave recordings in the first week of treatment would show that the antidepressant (as compared with a placebo) corrected the frequency imbalance — and predict a beneficial effect of medication on an individual’s depression after seven weeks.
Researchers analyzed data from 194 people, 18-to-70 years old, with major depressive disorder. The individuals fell into three groups: two comprised of 70 and 76 patients, each treated with escitalopram for seven weeks, and a third group of 48 patients treated with a placebo (the groups receiving escitalopram were part of separate studies evaluating the effectiveness of escitalopram compared with other types of antidepressants). All of the patients were given an electroencephalogram before starting and after one week.
Subjects who showed a large shift toward producing more delta-theta waves after one week were less likely to enter remission with escitalopram treatment. Conversely, those who shifted toward producing more alpha oscillations after one week with escitalopram treatment were significantly more likely to find relief from their depression. Brain-wave shifts did not predict treatment outcomes in patients given a placebo. The researchers next plan to use brain-wave recordings to evaluate other antidepressant medications, as well as cutting-edge, non-medication treatments such as transcranial magnetic stimulation, a magnetic method used to stimulate small areas of the brain.
“Escitalopram but Not Placebo Modulates Brain Rhythmic Oscillatory Activity in the First Week of Treatment of Major Depressive Disorder,” Journal of Psychiatric Research, October 7, 2016