Aimee Hunter, a research psychologist at the University of California, Los Angeles, has long studied individual responses to antidepressants. Being skeptical of the true effectiveness of the drugs, she says she was originally interested in researching the impact of placebos. But over the years, her own data began convincing her otherwise. "I’ve come to see now, by doing the research myself and spending hours looking at numbers, that the medication is absolutely doing something," Hunter says.
In an earlier study that Hunter published in 2009, she and her team used the same QEEG technique on 58 patients, who were given a placebo daily for one week before being randomized to take either placebo or an active drug. Researchers found distinct patterns of brain activity in the patients; not everyone responded to the placebo the same way. "We found that changes in brain function occurring during the first week of placebo predicted who will do well on medication," she says.
The region where changes were recorded—in the prefrontal lobe—is thought to be involved in generating expectations. A common explanation for the placebo effect is that the mere anticipation of improvement begets real benefit. But in the case of Hunter’s patients, the changes in brain activity predicted actual response to the antidepressant , not to placebo.
Intriguingly, in patients who showed the specific brain response associated with antidepressant-related recovery, the most significant improvement was seen in what psychologists call interpersonal sensitivity how people respond to either positive or negative social events. When suffering from depression, patients tend to become inured to positive social cues and oversensitized to negative ones. They may interpret a passerby’s frown as being directed at them, for instance, and some research has found that depressed people are more likely to misidentify smiling faces as conveying neutral or negative emotions. The patients who improved with medication in Hunter’s study "were less sensitive to rejection and more comfortable with others," she says.
Reducing emotional sensitivity—not treating depression per se—is what medications like Prozac, which affect the levels of serotonin in the brain, do best, according to Healy. If that entire class of drugs had been studied and marketed as pills to reduce emotional reactivity rather than depression, he says, "the placebo response would be very small compared to the drug. "
Still, treating a patient’s oversensitivity does not necessarily help depression. For some people whose illness is marked by social dread and misperceived rejections, reducing that anxiety could be critical. But for someone whose depression is primarily experienced as deep sadness and inability to feel pleasure, blunting emotional sensitivity may do little good. These differences further explain why the drugs may produce such varied individual responses.
Evidence suggests that about 80% of people with depression can be helped by drugs, talk therapy or a combination of the two, so although it is critical to figure out which treatments work for which patients, the larger question remains: Why aren’t most patients getting good care, and why do we continue to insist that so many of those taking antidepressants don’t really need them
Reducing emotional sensitivity（）
A. is what a placebo can do for patients
B. cannot help depressed patients at all
C. works better with some patients than with others
D. is the only thing an antidepressant can do