Antidepressants are some of the most commonly-prescribed drugs on the market, but you might be surprised that no one seems to know exactly how they do the work of relieving depressive symptoms. New research suggests that the drugs might be doing more than simply alleviating sadness. Instead, antidepressants may help patients by giving them the feeling of being in control of their lives. For the study, published last month in the journal Neurobiology of Learning & Memory, researchers recruited 76 people with mild depression and 78 people without depression. Everyone was given either a selective serotonin reuptake inhibitor (SSRI) antidepressant or a placebo for a week. Then, participants had to complete a task on the computer, which involved pressing a button until they heard a noise. In reality, the noise was programmed to happen on its own. After the task, participants rated how effective they felt their actions were and how "in control" they felt during the game. Results showed that, in general, depressed participants who were on the placebo reported feeling like they weren't in control. But those who had taken the SSRI felt like they had more agency. But it gets more complicated. The researchers also manipulated and measured other things (e.g. how often the noise actually happened and the number of times each participant pushed the button). They found that, rather than increasing our overall sense of "control," the drug might make it easier for us to learn and distinguish between the things we can control and the things we can't — which is probably more useful anyway. The researchers suspect the SSRI does this by manipulating the flow of serotonin in our brains, an effect that previous research has shown helps us create emotional memories. "In addition to the direct chemical effect," said Robin Murphy, PhD, one of the study's authors, in a press release, "the drug seems to contribute to learning to be in control, less constrained by the environment, and perhaps this might be a link to how these drugs contribute to the alleviation of depression." Depression is a complex, multifaceted disorder, so this isn’t the only thing going on. The same mechanism — serotonin's ability to help us create emotional memories — may also help people learn to break the cycle of negative thoughts.