The most widely prescribed class of antidepressants has finally been found to increase connections in the human brain.
This finding provides a plausible biological explanation for the drug’s delayed therapeutic response and could aid in the development of new targeted therapies.
It is unclear why it takes so long (usually several weeks). Selective serotonin reuptake inhibitor (SSRI) Achieve notable benefits. Understanding this delay could help medical professionals encourage patients to continue treatment and provide hope to millions of people affected by devastating conditions.
In the first human study of its kind, a global research team measured physical changes in neuron connections (synapses) after SSRI treatment in healthy adults.
“We found that in people taking SSRIs, there was a gradual increase in synapses in the brain’s neocortex and hippocampus over time.” To tell Gitte Knudsen, a neuroscientist at Copenhagen University Hospital in Denmark, says:
Increased neurotransmitter levels in the brain serotonin It is responsible for the mood-elevating effects of SSRIs. Unfortunately, they don’t work for everyone, and scientists still don’t know their exact mechanism of action.
it has been We hypothesized that SSRIs increase synaptic plasticity. inside the human brain. This ability of synapses to strengthen or weaken over time is thought to be important for learning, memory, and mood regulation.
Use a double-blind method to test your hypothesis. Semi-randomized controlled trial Thirty-two adults with no history of depression were surveyed. Participants were randomly assigned to receive either 20 milligrams of escitalopram (SSRI) or a placebo daily for up to five weeks.
The researchers used Positron emission tomography (PET) scans are used to measure brain levels of a protein called synaptic vesicle glycoprotein 2A (SV2A). The level of her SV2A protein in the brain indicates the presence of synapses. Higher levels in a particular region mean that the density of synapses in that region is higher.
The scans revealed significant differences between groups in the progression of synaptic density. People who took escitalopram showed higher levels of SV2A in the neocortex and hippocampus compared to people who took a placebo.
of neocortexIt is a complex structure that occupies about half of the volume of our brain and is responsible for higher mental processes such as emotion, sensory perception, and cognition. Patients taking escitalopram had a smaller increase in SV2A levels. Hippocampusan area deep within our brains that helps us remember and learn.
“This shows that SSRIs increase synaptic density in brain regions critically involved in depression,” Knudsen said. To tell.
“This goes some way to showing that synaptic density in the brain may be involved in the function of these antidepressants, and could give us a goal to develop new drugs for depression.” .”
Importantly, these differences took time to emerge. By the way, after an average of 29 days, there was no significant difference in SV2A density between the escitalopram and placebo groups.
The analysis showed that people who took escitalopram for a long time had a greater increase in synaptic density.
“Our data suggest that synapses accumulate over several weeks, which may explain why it takes so long for these drugs to take effect.” explain Knudsen. “People who took the placebo didn’t see any effect.”
Involving undiagnosed subjects made it possible to study the potential effects of SSRIs on synaptic plasticity without being influenced by clinical symptoms or brain pathology. Further research is needed to know whether this also occurs in patients with depression and whether it is associated with improvement in clinical symptoms.
“The delayed therapeutic effect of antidepressants has been a mystery to psychiatrists since they were first discovered more than 50 years ago.” To tell David Nutt, a neuropsychopharmacologist at Imperial College in London, was not involved in the study.
“So these new data, which use state-of-the-art brain imaging to demonstrate the increased brain connectivity that develops during depression recovery, are very exciting.”
This study was accepted for publication in a peer-reviewed journal and presented at an academic conference. European Society of Neuropsychopharmacology Conference.
