Medications, Therapy, Exercise in Treating Depression...All Remodel the Brain
It's possible to use the brain's lifelong neuroplasticity to treat disorders
Posted Jul 22, 2011
The fourth key concept of the New Neuropsychiatry as discussed in my book Heal Your Brain is that behaviors, and even our thoughts, are continually remodeling the brain. Medications and therapy also remodel the brain.
By thoughtful use of such treatments and by specific changes in behaviors, it is becoming increasingly possible to undo the damage associated with major depression and anxiety disorders...and to help people recover from these disorders.
Furthermore, we are starting to discover some of the biological factors that make brain remodeling possible, and that can be harnessed in order to help people recover from disorders.
It's important, of course, to admit that we are at the very beginning of this New Neuropsychiatry era, and that we have only the very first inklings of a new world of lifelong neuroplasticity.
Clearly our ideas will need updating and refining over time. But the vast tide of new neuroscience research providing us with more and better information about how to understand disorders-and clinically-informed research gives clues about how to apply this new knowledge to the patients we see every day.
As mentioned in an earlier posting, it has become clear that depression and other psychiatric disorders are bad for the brain. The brain and body's stress response systems are abnormally active in chronic depression. The body produces high levels of cortisone and other stress hormones, which are adaptive in the short run--preparing us for battle, so to speak--but toxic in the long run. Depression is associated with shrinkage of parts of the brain, and on a microscopic level with increased atrophy and even death of brain cells, and with decreased connectivity between brain cells.
If the brain is continually reshaping itself, if it is 'plastic' throughout life, but is injured by disorders, the question is: Is it possible to limit the process of brain damage and even to invoke a more positive 'healing' process in the brain? Not long ago, this question would have seemed absurd.
But in the past several years, fascinating studies have begun to show that antidepressant medications actually cause neurogenesis--or the actual development of new brain cells. SSRIs, lithium, valproic acid, and other classes of antidepressant medicines cause the growth of new brain cells in areas such as the hippocampus. Brain stimulation treatments such as electroconvulsive or magnetic stimulation treatment have the same effect. Conversely, medicines that are not antidepressants do not cause neurogenesis. Antidepressants appear to lead to increased size of neurons, and increased connectivity between brain cells. Indeed, neurologists are now starting to use SSRI antidepressants to help the brains of stroke victims recover more quickly.
Other recent studies have shown that physical exercise also has positive effects on brain health--most likely by increasing the production of 'neurotrophic factors' such as BDNF (brain-derived neurotrophic factor). A wide range of studies are underway--in 'animal models' and in humans--to test the effect of exercise on psychiatric and neurological disorders. Is it possible to use the exercise-induced boost in neurotrophic factors to help people recover from depression?
Other studies have shown that CBT has measureable effects on brain activity: Goldapple and colleagues published a fascinating study in 2004 showing the effects of cognitive behavioral therapy (CBT) on regional brain activity--which, interesting, were different than the effects of medication.
Our research group at Columbia and the New York State Psychiatric Institute is completing a pilot study in which we use behavioral activation therapy (BA) to help improve psychosocial functioning of people whose chronic depression has responded to antidepressant medication but who continue to be 'couch potatoes.' We hypothesize that by helping to activate the behavior of such individuals, to get them more involved in rewarding activities, that we will be able to change their patterns of brain activity--essentially to activate their brains' reward circuitry, a dopamine-based system that involves the nucleus accumbens.
Sounds far-fetched? A fascinating recent functional MRI (fMRI) study by Dichter and colleagues found that after BA therapy individuals with depression indeed did have more activity of their reward circuitry, using a 'Wheel of Fortune task'. We plan to try to replicate Dichter's study in our own research sample.
As a clinician, I can't help but wonder what changes in the brains of patients who achieve remission. In my book Heal Your Brain I talk about a patient Mark M., who had over a decade of severe depression and obsessive behavior following the death of his wife in an accident, who was able to enter prolonged remission after a combination of medications and behavioral therapy. Over time, Mark went from a life of fearfulness and avoidance to a life of rewards and pleasure. He was able to finally get married, to decide to have children, to buy a house, and otherwise to move on with his life. I'd love to have MRI scans of his brain before and after that personal transformation!
New Neurosciences research suggests that the damaging processes of severe disorder can be interrupted, and that by helping people to get back to their lives, we can activate the brain's 'reward circuitry' in a sustained way.
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