Brain Scans Give Clues to Antidepressant’s Effects

Brain scans during memory tests might help predict which depressed patients will be helped by a fast-acting drug, a new study reports.

Major depression is marked by feelings of sadness, loss, anger or frustration that can interfere with daily life for many weeks. Symptoms can also include memory loss and trouble focusing.

Most depression-fighting drugs must be taken for several weeks before working, which can cause an agonizing wait for patients. Because different people respond to different medications, patients may need to try several drugs over a month or more before getting symptom relief.

Several years ago, NIH researchers discovered that a drug used to treat motion sickness could also rapidly reduce symptoms of depression. But the drug, called scopolamine, didn’t work in all patients. 

To try to predict the drug’s effects, the researchers used MRI to track brain activity in adults with and without major depression. People with major depression are known to have unique patterns of brain activity when asked to pay attention to the emotional content of images. They also tend to remember negative information (such as sadness) better than positive or neutral information.

The researchers found that scopolamine relieved symptoms in 11 of the 15 participants who had major depression. Scopolamine’s effectiveness was linked to activity in a specific brain region when patients were asked to remember the emotions on faces that flashed by. Activity in this same brain region was also altered by infusions of scopolamine.

The findings suggest that activity in this brain region might provide early clues about how well scopolamine will work in different patients. Ongoing studies are exploring how the brain’s response to emotional images might help guide treatment strategies for major depression.