It is popularly believed that SSRIs, like Prozac and Zoloft, only produce good feelings.
In fact, in the first few weeks of treatment, common antidepressants can cause increased anxiety and fear.
Serotonin — the neurotransmitter that is boosted by SSRIs — is even linked to suicidal thinking, especially in young people.
New research, though, could provide a clue as to how the effect can be reduced.
Researchers have traced a serotonin-activated pathways in the brains of mice that leads to anxiety.
The circuit could be crucial to how SSRIs produce short-term anxiety.
Professor Thomas L. Kash, who led the research, said:
“The hope is that we’ll be able to identify a drug that inhibits this circuit and that people could take for just the first few weeks of SSRI use to get over that hump.
More generally, this finding gives us a deeper understanding of the brain networks that drive anxiety and fear behavior in mammals.”
Having identified the crucial circuit in the brain, the researchers moved on to trying to block it.
They were able to this with a ‘CRF blocker’, but as this research was in mice, it is not clear if the same result would be seen in humans.
Professor Kash said:
“It’s logical that it would since we know SSRIs can induce anxiety in people, and the pathways in these brain regions tend to be very similar in mice and humans.”
Professor Kash said:
“Other researchers are working to develop better CRF-inhibiting compounds, so that’s one potential direction to take, but there are others.
We’re now looking at the various proteins expressed by these BNST neurons, and we’re hoping to identify a receptor that is already targeted by established drugs.
One of them might be useful for people as they start taking SSRIs.”
About the author
Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology.
He has been writing about scientific research on PsyBlog since 2004. He is also the author of the book “Making Habits, Breaking Habits” (Da Capo, 2003) and several ebooks:
- Accept Yourself: How to feel a profound sense of warmth and self-compassion
- The Anxiety Plan: 42 Strategies For Worry, Phobias, OCD and Panic
- Spark: 17 Steps That Will Boost Your Motivation For Anything
- Activate: How To Find Joy Again By Changing What You Do
The study was published in the journal Nature (Marcinkiewcz et al., 2016).