Prozac’s effect on the brain
This news story from the New Scientist gives the latest news in the ongoing exploration of how Prozac works to produce its therapeutic effects. When Prozac was first available, the idea was that a depressed brain was suffering from a lack of available serotonin, and that Prozac and other drugs in its class (selective serotonin reuptake inhibitors, or SSRIs) helped by increasing the amount of serotonin circulating in the brain. However, this didn’t explain why people typically have to wait for several weeks before seeing any effect, despite the fact that serotonin levels go up right away. Scientists are discovering that the mechanism is a lot more complicated than a simple lack of serotonin. Serotonin can promote neurogenesis, the birth of new brain cells, and Prozac seems to work by promoting neurogenesis in the hippocampus. And not only SSRIs, but other antidepression treatments affect a type of protein that is involved in neurogenesis. The current New Scientist article describes some research that narrows down the point at which Prozac influences the process of neuron birth. There are still a lot of unanswered questions, like why enhanced neurogenesis makes some depressed people feel better, or maybe, looked at from the other side, why depression is linked to a slowdown in neurogenesis. You can read more about the link between Prozac, neurogenesis, and depression in a recent article from Seed Magazine focusing on neurogenesis and a 2001 article from Discover that focuses more on serotonin.
Serotonin is implicated in so many diseases and disorders. A few that I’m familiar with
besides depression are fibromyalgia, migraines, and insomnia. Certainly depression is
quite common, and I’d say migraines and insomnia are fairly so as well. Why are so
many of us so short on serotonin? Is it a result of modern lifestyles
(too much sitting and driving and not enough walking and other physical exertion?)
or diets (not enough fish and fruits and veggies, too many refined grains?), or
has it always been thus and we are only now becoming aware of serotonin-related
problems because we have the science to reveal them?
Maybe it’s a little of both (modern lifestyles/diet and an increased awareness of the problem). This is purely speculation, but it seems like the disorders that are related to a shortage or imbalance of serotonin are not the kind of thing that will kill you before you reproduce, and thus there’s no selection pressure to breed out the ability to walk around a pint low. So maybe there’s always been a certain amount of serotonin deficiency that’s part of the human condition.
BTW I just ran across this serotonin necklace, from a place called Made With Molecules. You can also get a number of other neurotransmitter-related stuff. I like the estrogen necklace.