Findings published on September 18 in the journal ‘Current Biology’ by neuroscientist Dr. Julia Sacher, co-author with other researchers, at the Max Planck Institute in Leipzig, Germany, might finally provide clues to the brain’s response to some antidepressants.
Using a magnetic resonance imaging machine, they compared activity in the brains of those who ingested SSRI’s and those who did not. Within 3 hours, they were surprised to see the entire architecture of the brain change.
More than 1 in 10 adults in the U.S. use these drugs, which increase a higher presence of a chemical transmitter in the brain, Serotonin, by blocking its re-absorption. The so-called Selective Serotonin Reuptake Inhibitors, or SSRIs, include Prozac, Lexapro, Celexa, Paxil and Zoloft.
“Most people who use antidepressants don’t report any discernible change in mood for at least two weeks.” said Sacher, who also is a psychiatrist.
It is this lag time between the administration of an SSRI and any noticeable signs of efficacy that has plagued doctors and patients for years. The conclusions of this study might significantly help psychiatrists to identify what drugs seem to work and to come to the aid of depressed patients more quickly.
Dr. Sacher and her fellow researchers relied on a late 1990’s discovery that low-frequency brain signaling during inactivity, such as daydreaming, was a good indicator of functional connectivity. “We just tell them to let their minds wander and not think of anything particularly dramatic or upsetting” said Dr. Sacher.
They were able to create not only 3-D maps of connections from anatomical connections but low-frequency brain signaling, as well. These rapid connectivity shifts may prove to be precursors to long term changes, remodeling synapses that provide chemical neurotransmitters such as serotonin greater access to neighboring brain cells.
Dr. Sacher added, however, that the brain scanning used in the study could not pick up changes at such a granular level and that their hypothesis should be tested in other ways.
The significance of measuring the effect of various anti-depressants on a patient’s brain cannot be overstated. In April of this year, the LA Times published new research that found that kids and young adults starting on high doses of antidepressants are at a higher risk of suicidal thoughts and behaviors, especially in the first three months of treatment. The ability to gauge a patient’s almost immediate response to an anti-depressant would be priceless.
Another study released on April 29, in the Journal of the American Medical Association, conducted by epidemiologists at Harvard University and the University of North Carolina found no increased risk of suicidal behavior among adults older than 24 who started initial doses at higher levels. However, arbitrarily assigning risk by age may not be advisable, either.
The author of an invited commentary in JAMA Internal Medicine suggested, that given that antidepressants appear to be less effective in younger people, higher doses do not appear to bring faster relief. He recommended that prescribing physicians should abide by the well-worn maxim “start slow, go slow,” and monitor patients carefully.