Exciting but not conclusive
Session co-chair Oliver Howes, MD, PhD, professor of molecular psychiatry, King’s College London, agreed that the results do not prove the gradual increase in synaptic density the treatment response lag with SSRIs.
“We definitely don’t yet have all the data to know one way or the other,” he said in an interview.
Another potential hypothesis, he said, is that SSRIs are causing shifts in underlying brain circuits that lead to cognitive changes before there is a discernable improvement in mood.
Indeed, Dr. Howes suggested that increases in synaptic density and cognitive changes related to SSRI use are not necessarily dependent on each other and could even be unrelated.
Also commenting on the research, David Nutt, MD, PhD, Edmond J. Safra professor of neuropsychopharmacology at Imperial College London, said that the “delay in therapeutic action of antidepressants has been a puzzle to psychiatrists ever since they were first discerned over 50 years ago. So, these new data in humans, that use cutting edge brain imaging to demonstrate an increase in brain connections developing over the period that the depression lifts, are very exciting.”
Dr. Nutt added that the results provide further evidence that “enhancing serotonin function in the brain can have enduring health benefits.”
Funding support was provided by the Danish Council for Independent Research, the Lundbeck Foundation, Rigshospitalet, and the Swedish Research Council. Open access funding provided by Royal Library, Copenhagen University Library.
Dr. Knudsen declares relationships with Sage Biogen, H. Lundbeck, Onsero, Pangea, Gilgamesh, Abbvie, and PureTechHealth. Another author declares relationships with Cambridge Cognition and PopReach via Cambridge Enterprise.
A version of this article first appeared on Medscape.com.