Can One Dose Of Antidepressant Lead To Changes In Your Brain? September 19 2014
By Forbes Contributor: Robert Glatter, MD
It is estimated that up to 1 in 10 adults suffer with depression. Medications for treating depression can be effective, yet certain medications which are taken for depression such as SSRIs, (selective serotonin reuptake inhibitors) may take up to a month or longer before patients begin to experience relief of symptoms. Still, some patients may not respond to such medications, making treatment problematic and frustrating.
Now, new research into how medications such as SSRIs actually work in the brain may offer new potential to help physicians and other medical providers select the most effective therapy.
The concept of “personalized medicine”, whereby specific medical therapies are tailored to a person’s unique genetic structure or chemical makeup may hold promise for helping more patients.
As part of this approach, researchers have long been intrigued as to whether a single dose of antidepressant can lead to actual changes in the neural networks and chemical structure of the human brain.
Now, according to new research published online September 18th in Current Biology, MRI scans taken of people before and after one dose of an SSRI demonstrated actual changes related to connectivity within three hours.
“We were not expecting the SSRI to have such a prominent effect on such a short timescale or for the resulting signal to encompass the entire brain,” said Julia Sacher of the Max Planck Institute for Human Cognitive and Brain Sciences, lead author of the study.
It’s actually not completely clear how SSRIs truly work. But research suggests that they alter brain connectivity in specific pathways; however, the effects typically have been thought to take place over a period of weeks, not hours.
Changes are now shown to take place immediately, according to the new findings. Sacher believes that such changes–especially in those who have never taken SSRIs–may in fact represent early indications of brain reorganization.
In the study, MRI scans were used to measure the oxygenation of blood flow in the brain in the study participants. The researchers developed a three- dimensional model of each individual’s brain by recording the number of connections between small blocks known as voxels (comparable to the pixels in an image) and the resulting change in these specific connections after given a single dose of escitalopram (Lexapro).
A whole-brain network analysis demonstrated that one dose of the SSRI actually decreased the level of intrinsic connectivity in the majority of regions of the brain. However, the researchers noted an increase in connectivity within two specific areas of the brain, the thalamus and cerebellum.
These new findings, according to the researchers, may represent an important advance that could become a new approach to evaluate patients suffering from depression. This could also lead to a comparison of the functional connectivity of brains in recovery and those of patients who fail to respond after weeks of SSRI treatment.
Understanding the differences between the brains of individuals who respond to SSRIs and those who don’t “could help to better predict who will benefit from this kind of antidepressant versus some other form of therapy,” Sacher said. “The hope that we have is that ultimately our work will help to guide better treatment decisions and tailor individualized therapy for patients suffering from depression.”
The recent study, according to Paul J. Mattis, PhD., Chief of Adult Neuropsychology at North Shore University Hospital in Manhasset, NY, “provides an insight into the neural systems involved in the initial/acute effects of serotonin, a neurotransmitter commonly associated with depression.”
“The findings indicate that compared to subjects who were administered a placebo, the subjects receiving the SSRI exhibited a considerable change in the degree different brain regions (neural networks) communicate,” said Mattis.
“Although not directly relevant to patients with depression, the study provides a small building block in the substantial task of understanding the brains of patients with depression and other disorders in which serotonin is important,” added Mattis.