In this study, brains of around 22 healthy people who had never taken antidepressants before, was scanned. The functional connectivity of the brain was analyzed by the scientists. This measures the synchronization of brain activity in different areas.
Within 3 hours of taking the antidepressant medication known as SSRI or a selective serotonin reuptake inhibitor, a dramatic decrease was shown in the functional connectivity across the whole brain.
Dr. Julia Sacher, the researcher of the study said that they weren’t expecting such a prominent effect of the SSRI on such a short timescale. They also didn’t expect the resulting signal to encompass the whole brain.
The connectivity changes that are reported here are much acute and dramatic as compared to the previous reports on SSRI-action in human brain.
Although SSRIs are prescribed widely, researchers aren’t yet aware of how the medications work for improving mood. It is just known that the levels of brain chemical serotonin are affected by these drugs. Specifically, the reabsorption of serotonin brain cells is blocked by them. Thus, the levels of free serotonin outside the cells is increased.
It is thought that owing to the changes in the levels of serotonin, reorganization of the brain is seen and brain cell proliferation may be affected. Also, the efficiency of cell signal transmission may be affected.