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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 8 of 8. This is the beginning of the thread.
Posted by Arthurgibson on August 9, 2003, at 4:58:15
http://news.bbc.co.uk/1/hi/health/3136613.stm
Drugs designed to relieve depression may be working because they stimulate the growth of new nerve cells in a key area of the brain, say researchers.
It had been thought that the drugs operate by influencing the way brain chemicals work, but evidence is emerging that the changes they produce are more far-reaching.
Research was carried out on mice placed into a new living environment - normally their anxiety at the change means they do not eat for a while.
However, antidepressant treated mice tend to take a shorter period to overcome their anxiety.
The results were published in the journal Science.
The researchers found that when these animals given a modern "SSRI" antidepressant called fluoxetine the number of neurons in an area of the brain called the hippocampus doubled.
This area is known to be important in mood and memory, and accordingly, as expected, the mice showed fewer signs of anxiety.
However, when these mice were given selective x-ray treatment which prevented the development of the new cells, the result was different.
The mice enjoyed no improvement in their mental state despite being given the antidepressant.
This suggests, say the researchers, that the arrival of the new neurons may be as important for antidepressant users as other chemical effects on the existing brain cells.
It is possible that future drugs could be targeted more precisely to stimulate neuron growth in the hippocampus, they say.
Dr Thomas Insel, a director of the National Institute of Mental Health in the US, said: "This is an important new insight into how antidepressants work.
"We have known that antidepressants influence the birth of neurons in the hippocampus - now it appears that this effect may be important for the clinical response."
However, scientists are still a long way from figuring exactly how the antidepressant triggers this cell growth.
Experiments with genetically engineered mice have suggested that a particular "receptor" on the neuron plays a key role in this process, but much work remains to confirm this.
There is no certainty that a human brain will respond in a similar way to a mouse brain.
However, Dr Tony Cleare, from the Institute of Psychiatry told BBC News Online that the theory made sense.
He said: "We know that the hippocampus can be smaller in people with chronic depression.
"What we don't know is if it can recover."
Posted by Dinah on August 9, 2003, at 8:48:16
In reply to Antidepressants 'grow brain cells', posted by Arthurgibson on August 9, 2003, at 4:58:15
That's so odd. I would have sworn that my four years on Luvox destroyed (or seriously damaged) any memory related brain cells I had. So would my boss. :(
Maybe a different sort of memory.
Posted by mattdds on August 9, 2003, at 15:40:56
In reply to Re: Antidepressants 'grow brain cells' » Arthurgibson, posted by Dinah on August 9, 2003, at 8:48:16
Hi,
I've been hearing so much about this lately. Although these findings are interesting and could eventually give clues about the biology of depression, it's hard to know if these findings are applicable to humans.
I also have to wonder if someone had a spontaneous recovery, or if he/she recieved a non-somatic treatment, such as CBT or other psychotherapy (assuming it was successful), if you would see the same neurogenesis in the hippocampus.
My point is, I wonder if this is not just another biological marker in recovery from depression in general (like the whole serotonin thing apparently turned out to be), that *corresponds* with, but is not necessarily causally related to the SSRI per se. I read somewhere that SSRI treatment reduces cortisol mRNA expression in *successful* treatment, but not in unsuccessful treatment. I also wonder if *successful* *placebo* treatment (this does occur) induces hippocampal neurogenesis.
In my case, I don't care how many new neurons were growing in my hippocampus when I took Celexa, Zoloft, Paxil, and Prozac. The most important thing to me was that they significantly worsened my symptoms.
I'm not saying this is not an important finding, because it certainly is interesting and groundbreaking. I just would hate to see this become the next "monoamine hypothesis", which we all know was highly inadequate to explain depression.
I can just picture the new antidepressant commercials - presenting all the data on how SSRI's induce neurogenesis, and how they grow new brain cells. To me what is important is that they WORK!
Matt
Posted by slinky on August 9, 2003, at 19:59:54
In reply to Re: Antidepressants 'grow brain cells' » Arthurgibson, posted by Dinah on August 9, 2003, at 8:48:16
Posted by Shawn. T. on August 10, 2003, at 18:00:40
In reply to Would successful *placebo* induce neurogenesis? , posted by mattdds on August 9, 2003, at 15:40:56
Posted by BekkaH on August 10, 2003, at 18:20:11
In reply to Would successful *placebo* induce neurogenesis? , posted by mattdds on August 9, 2003, at 15:40:56
Hi Matt. Thanks for a great post. I don't know what you're on now, but it's clear that you are doing some very good thinking!
Posted by mattdds on August 10, 2003, at 21:46:19
In reply to *placebo* induce neurogenesis?- mattdds, posted by BekkaH on August 10, 2003, at 18:20:11
>>I don't know what you're on now
LOL. Just about 1 mg of Klonopin daily. That's all that works for me as far as medications. AD's dont' do anything positive for me, unfortunately. However, it's clear they can be helpful to some.
I take CBT too, but that's not really a drug. But it works for me. I always give the estimate that CBT decreased my symptoms by 80%, and Klonopin the other 20%. I've felt quite well for about a year now.
>>but it's clear that you are doing some very good thinking!
Thanks! Nice to hear my ideas make sense to someone else besides me.
Matt
Posted by mattdds on August 10, 2003, at 21:48:59
In reply to Good points Matt (nm) » mattdds, posted by Shawn. T. on August 10, 2003, at 18:00:40
Shawn,
Thanks, that means a lot from someone as knowledgable as yourself.
Best,
Matt
This is the end of the thread.
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