A new study carried out by scientists from the department of Neurology at the Max Planck Institute in Leipzig (Germany) has concluded that despite the belief that for antidepressants to have an effect it is necessary for the patient to take it for at least 4-6 weeks, a single dose already causes significant changes in the brain in a matter of hours .
The research, which has been published in the journal Current Biology , aimed to investigate how selective serotonin reuptake inhibitors (SSRIs), the most commonly prescribed antidepressants in the treatment of anxiety, personality or depression disorders ( Prozac, Lexapro or Zoloft , for example), act in the human brain.
For this, they had the participation of 22 healthy subjects. Each of them underwent a 15-minute brain scan that measured oxygenation of the brain’s blood flow. They were then given a dose of Lexapro before undergoing the brain scan again about three hours later.
Comparison of both brain scans revealed that the drug reduced connectivity levels in most areas of the brain after three hours ; however, it also increased the connectivity of two specific brain regions : the cerebellum (involved in voluntary movement) and the thalamus (involved in sensory perception and motor function). That is, the dose of Lexapro altered brain connectivity and increased the production of serotonin, a neurotransmitter believed to play an important role in maintaining mood balance.
” We did not expect the SSRI to have such a significant effect in such a short time or to encompass the entire brain,” says Julia Sacher, leader of the study. According to the researchers, these results suggest that SSRIs can reorganize the brain early to reduce symptoms of depression and not as long-term as previously thought.





