Neuro-plasticity and Depression (Part Two)
In my last blog I introduced the concept of neuro-plasticity. Neuro-plasticity describes the brain's ability to change and grow throughout our lifetime. Lately there has been a whole lot of new information coming out about depression and much of it relates to this concept of neuro-plasticity. It's all so exciting that it's going to take me several blogs to even touch on all the new information that is coming to light. And I think one of the main reasons that people are looking for some new answers to depression is that the old answers are now coming under fire.
The Journal of the American Medical Association (JAMA) just published an article which flatly stated that anti-depressants were no better than a placebo in treating mild to moderate depression. This is really dramatic news, especially when published in a peer-reviewed medical journal like JAMA. This news has a lot of family physicians up in arms. Family doctors are the ones who most commonly prescribe these ubiquitous drugs (not psychiatrists) because they see the devastation caused by depression first hand. They also see how depression - in many cases - is mediated by anti-depressants, particularly by SSRIs (Serotonin Reuptake Inhibitors) which raise the level of serotonin in the brain.
But the mystery has always been, that if increasing the amount of serotonin in the brain was the answer to depression, why don't these SSRIs help everyone who takes them? (It only works in about half the cases.) One answer may be that it's the placebo effect that is really helping patients not the SSRIs. (Most of the double blind studies conducted with SSRIs show them only slightly more effective than a placebo, or sugar pill.)
Another answer to the above question (why don't SSRIs help everyone) may be explained by the neurogenic hypothesis of depression. This theory suggests that the reason SSRIs work - is that in some cases - these drugs promote the growth of new neurons. And this explains another mystery of SSRIs which is why it takes them three weeks to kick in. (For, if lack of serotonin in the brain was the reason we get depressed, why wouldn't the pills work immediately?) But the neurogenic hypothesis of depression suggests that that's how long it takes for the brain to start making new neurons and creating new neuronal pathways.
It also helps to explain why depressed patients are so hard to treat - without drugs. When depression is brought on by a traumatic event, say the death of a loved one, a divorce or the loss of a job, some people fall into a rut, perceptually piling bad news upon bad news and feeling like they are never going to get better. It's hard for these depressed patients to even get out of bed, let alone take on new challenges and activities that might stimulate brain growth. (So the theory goes, that even though the SSRIs immediately raise the level of serotonin in the brain, it's the promotion of brain growth that may be what's lifting people out of depression. And that takes about three weeks to get started.)
In a nutshell, this is the neurogenic explanation for mediating depression without drugs: New activities, new behaviors, change, socializing with friends and family all promote brain growth. And it may be this brain growth which is the real enemy of depression. So some day, this neruogenic hypothesis may replace the old neuro-transmitter (serotonin is a neuro-transmitter) explanation . And if you believe what JAMA is reporting the old neuro-transmitter explanation may be half-dead already. *
In my next blog I'll talk about some of the things you can do to promote neurogenisis. In the mean time you may wish to read the book by Norman Doidge: The Brain That Changes Itself.
*Please do not make any changes in your approach to depression, especially in regards to prescriptions, without consulting your doctor first. The neurogenic theory of depression is just that, a theory. If you are affected by depression, let this blog be the start of a conversation between you and your doctor. Be sure to ask if he or she has seen the latest information concerning SSRIs in JAMA. Doctors trust JAMA to deliver information that is peer-reviewed.
James Porter
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