Depression: Beyond Serotonin

Surprising new findings are challenging the assumption that the world�s most common mental ailment is "just" a chemical imbalance in the brain.  The latest research shows that the actual circuitry of the brain is impaired, even destroyed. What�s more, the disorder appears to afflict the body as much as the brain.

By Hara Estroff Marano

Death was now a daily presence, blowing over me in cold gusts. Mysteriously and in ways that are totally remote from normal experience, the gray drizzle of horror induced by depression takes on the quality of physical pain. But it is not an immediately identifiable pain, like that of a broken limb. It may be more accurate to say that despair, owing to some evil trick played upon the sick brain by the inhabiting psyche, comes to resemble the diabolical discomfort of being imprisoned in a fiercely overheated room. And because no breeze stirs this caldron, because there is no escape from the smothering confinement, it is entirely natural that the victim begins to think ceaselessly of oblivion.

Melancholy, apparently, is a fertile muse. No sooner had William Styron become the poet laureate of depression after describing his bout with madness in Darkness Visible  (Random House, 1990) when all manner of confessions followed. Mike Wallace. Art Buchwald. Dick Cavett lined up to disclose their own struggles with the disabling disorder. It quickly became acceptable, even chic, to publicly confide vulnerability to depression.

At the same time, the world was being made safe for depression, or at least public revelations of it, by another development, the 1988 advent of the so-called SSRIs�Prozac, Paxil and related drugs believed to specifically combat depression by beefing up serotonin and other neurotransmitters that ferry signals between nerve cells. The wild success of psychiatrist Peter D. Kramer�s thoughtful Listening to Prozac  (Viking) in 1993 generated not only new respect for the effectiveness of Prozac but new appreciation of the disorder it was intended to treat.  There followed hundreds of new book titles on depression, over 100 on Prozac alone, surely making it the most heralded drug on the planet. Depression chic cannot be dismissed as a passing fad because, it turns out, how the disorder is defined and popularized deeply shapes what patients are willing to do about it.

Despite the flood of Prozac prose, depression itself has remained, as Styron saw it, a mystery. It is one of the cruel ironies of science that it can explain the most bizarre and rare conditions to strike us. Take Capgras� syndrome, in which, due to an injury to the machinery for the emotional (but not perceptual) evaluation of visual objects, people develop the delusion that a poseur has taken the place of a loved one. But common afflictions like depression�Western countries� second most disabling ailment (after heart disease) and the world�s fourth�have long eluded understanding. That, however, is beginning to change.

In the last two or three years alone, the refinement of brain-  imaging techniques is providing an unprecedented look into the neurobiology of depression, showing what goes on in the brains of patients as they process positive and negative experiences.  Though just beginning, the work is already producing a radically revised view of depression that promises to shape new treatments for the future. Among the emerging findings:

o Regarding depression as "just" a "chemical imbalance" wildly misconstrues the disorder. "It is not possible to explain either the disease or its treatment based solely on levels of neurotransmitters," says neurobiologist Ronald Duman, Ph.D. of Yale University.
 The newest evidence indicates that recurrent depression is in fact a neurodegenerative disorder, disrupting the structure and function of brain cells�destroying nerve cell connections, even killing certain brain cells, and precipitating cognitive decline. At the very least, depression sets up neural roadblocks to the processing of information and keeps us from adaptively responding to whatever challenges life throws our way.

o There does not appear to be a single genetic cause of depression, although there does seem to be a form of major depression that is strongly familial. Rather, the disorder likely results from multiple biological and environmental factors. "There may be lots of ways to get there�and lots of ways to get out of it," says Kramer, associate professor of psychiatry at Brown University.

o Human emotions take shape in a neural circuit involving several key brain structures, including the hippocampus, the amygdala, and the prefrontal cortex. In depression, faulty circuitry begets failure both in generating positive feelings and inhibiting disruptive negative ones.

o Stress-related events may kick off 50% of all depression and early life stress can prime people for later depression. Ongoing research both in animals and in people demonstrates that such early strain  can enduringly alter nerve circuits that control emotion, permanently exaggerating later responses to stress and leading to the neurochemical and behavioral changes of depression. In other words, the deeper researchers probe the brain, the more they validate the psychoanalytic view that early adverse life events can create adult psychopathology.

Bold new research spanning the clinical and the molecular ties physical and  sexual abuse in childhood to depression in adulthood via changes in the  genetic expression of brain hormones.

It's not all in the head. Depression is not just an affliction from the neck up but a disorder involving many body systems.  It both leads to heart
disease in otherwise healthy adults and greatly magnifies the deadliness of pre-existing cardiac problems. What�s more, it accelerates changes in bone mass that lead to osteoporosis. "The lifetime risk of fracture related to depression is substantial," a team of researchers recently declared in the New England Journal of Medicine.

oJust as nerve cell connections can be destroyed in depression, perhaps they can be rebuilt. The common denominator in all effective antidepressant treatments, including electroshock, may be their ability to stimulate the sprouting of neurons in key brain regions, literally the forging of behavioral flexibility. A neurochemical pathway newly identified inside nerve cells promises to revolutionize therapy by allowing for treatments that do this better, faster, and more explicitly.

 o The adult brain has a degree of plasticity that is astonishing researchers and that promises to revolutionize thinking about human behavior. "All these changes, cell loss, atrophy of connections, that�s very new, and they�re still catching people by surprise," says neurobiologist Bruce McEwen, Ph.D., of New York�s Rockefeller University. "We thought that after birth, the brain is a stable organ like a little computer that just works away, and no more new nerve cells are produced. The emphasis before was on chemical imbalances, as if the circuitry itself was fairly stable. The big news is the structural plasticity of the adult brain, the remodeling of neurons. The idea that there are long-lasting, even permanent changes, in structure and function that can affect the way our brain processes information is the most important part of what we�re doing in the lab."

To understand depression we have to confront the mind/body dilemma head on. Although we often arbitrarily divide the mind from the brain and act as if "mental illness" were strictly mental, mood disorders are not ethereal, disembodied ailments. If depression proves anything, the mind and the brain are one. There are nerve circuits in the brain that color psychological events positively and negatively, that lead us to see rewards and pleasures or merely emptiness and hopelessness, and then to negotiate the world either by engaging it or withdrawing from it.

Such nerve circuits connect widely with other brain actions, and they malfunction in depression, spreading the malaise into every fiber of being. What sets the malfunction in motion may be some environmental circumstances, such as neglect of a child, or some internal physical fact, such as a faulty gene that controls a brain enzyme. Or, likely, some highly individualistic collision of the two.

Circuit Riding
Depression appears to hold the very soul hostage, with total lack of energy, disturbed sleep, loss of interest in food and sex, inability to experience pleasure, difficulty concentrating and thinking clearly, impaired short-term memory, self-blame, and inability to see alternatives.. But the disorder�s full-blown misery likely arises in just a few distinct centers in the brain. These hubs have discrete channels of communication with each other, their messages sent out over long filamentous arms extending from the cell bodies in one center to those in another.

One seminal spot in the circuitry of depression is the prefrontal cortex (PFC), the brain area just behind the forehead, which acts as the executive branch of emotions. According to Richard Davidson, Ph.D., professor of psychology and psychiatry at the University of Wisconsin, two of the PFC�s most important functions are restricted to one side or the other. His studies show that the left side of the PFC is crucial to establishing and maintaining positive feelings, while the right is associated with negative ones. Depressed people appear to have a  power failure  of the left PFC. The failure shows up both in electrical studies of brain response and PET scans indicating decreased blood flow and metabolism. The depressed simply don�t activate the machinery to process positive emotions or respond to positive stimuli.

Specifically, the left PFC is instrumental in what Davidson calls "pre-goal attainment positive affect", what you and I might call eagerness ( the positive emotion that arises as we approach a desired goal. Depressed individuals can�t mentally hang on to goals or keep themselves attuned to rewards. The result: lowered capacity for pleasure, lack of motivation, loss of interest.

But the left PFC doesn�t just activate positive feelings. Davidson finds that it may also be crucial in inhibiting negative emotion that gets in the way of sustaining positive goals. In this, the left PFC draws on its connections to the amygdala, an almond- shaped structure deep in the center of the brain that pumps out negative feelings.

By placing experimental subjects in a functional magnetic resonance imager to measure brain activity while showing them emotionally laden pictures�photographs of accidents and starving children, for example�Davidson has graphically confirmed what many scientists have long suspected: that the amygdala scans incoming experience for emotional significance, puts a flag on negative feelings such as fear, and sends out notice of threat.

If the PFC masterminds depression by failing to activate, the amygdala controls the severity of depression by its negative out put. Along with the University of Pittsburgh�s Wayne C. Drevets, M.D., Davidson has found that blood flow in the amygdala  is greater the more severely depressed a person is. Moreover, studies show that the amygdala is particularly active during states of experimentally induced helplessness, such as when people try to solve an unsolveable task. The activity of the amygdala also determines how tenaciously a negative event is held in memory.

Ordinarily, as the left PFC turns on, it simultaneously shuts off the amygdala and dampens the flow of negative emotions from it. But among the depressed, the general failure of activation of the left PFC leaves the amygdala running unchecked, overwhelming them with negative feelings.
Individuals normally differ in the degrees of neural activation of the left and right sides of the PFC in response to emotional messages. That difference may help account not only for a person�s vulnerability to depression, Davidson says, but also for variations in personality. A peppy left PFC underlies extraversion, while a relatively more active right PFC is linked to inhibition and anxiety. Left-sided activation prompts people to approach situations, right-sided activation to withdraw from them..

It isn�t clear how asymmetries in  prefrontal activity  get established to begin with. "Although these characteristics of brain function are very stable in adults," Davidson says, "they are much less so in children." That suggests to him that activation levels of this circuit are set early in life," after a sensitive period, certainly by puberty.

One clue may be that differences in PFC activation go hand in hand with differences in brain levels of the stress-related hormone cortisol. When the left PFC is highly active, not only do people have a sunny outlook, their levels of cortisol are insignificant. Cortisol patterns suggest that stress had a hand in there somewhere.

No Glee over Glia

Barely two years ago,, Wayne Drevets, then at Washington University, discovered that depressed persons not only have altered PFC activity, but their prefrontal cortex is actually smaller. It is one thing to find abnormalities in the way the brains of the depressed function�but structural  abnormalities? Anatomical  ones?

Drevets found that depressed patients have a drastically smaller volume of a section of the left PFC that sits about two and a half inches behind the bridge of nose and which is called the ventral anterior cingulate. Drevets likes to call it the subgenual prefrontal cortex because it sits beneath the genua, or knee, of the corpus callossum, the Continental Divide of the brain. The little site was 40% smaller in the depressed.

The subgenual cortex is vastly important: it is one of the few cortical regions that connects with the hypothalamus, a deep-brain structure that instigates the body�s stress response.  The subgenual cortex helps as well to orchestrate the body�s hormonal response to stress and to threatening stimuli. It also is the spot that helps us appreciate that something is rewarding.

Taking their cue from Drevets� findings, colleagues at Washington University got out their microscopes and began looking to see what could account for the cortical shrinkage. They examined tissue that, at autopsy, had been collected from the brains of normal persons and those with bipolar or unipolar depression. At the most recent meeting of the Society for Neuroscience, graduate student Dost Ongur reported the astonishing findings.

He had expected to see a decrease in the number of neurons, what he calls "the business end of the brain in terms of processing information and generating actions." Instead he found a dramatic loss in the number of glia, small cells that perform important�maybe critical�housekeeping functions for the more patrician neurons. And the loss of glia was seen only in those with a family history of depression.

Unglued by Glutamate

The glia are known to nourish neurons, by assuring a steady supply of glucose, their preferred food. They also protect neurons by stabilizing levels of the neurotransmitter glutamate. Glutamate is the main transmitter in the cortex that activates cells. Important as glutamate is, too much of it can overstimulate neurons, causing the collapse of the branches by which they communicate with other cells.

The glia also play a big role in the development of the serotonin neurotransmitter system, which, practically everyone now knows, also functions abnormally in depression, at least in some nerve circuits. "It could be," Drevets says, "that some defect in development of the prefrontal cortex could be the initial abnormality in depression that starts a cascade of changes in other systems."

It may also be that the action of antidepressant drugs on serotonin is less important than their action on glutamate. Researchers know that one effect of antidepressants is to reduce the sensitivity of receptors in the PFC for glutamate. "Suddenly," says Drevets, "that makes sense. Agents that desensitize the frontal cortex to glutamate may be compensating for the loss of glial cells."

Of course, that still leaves the possibility that a serotonin deficit in other parts of the brain could induce other depressive symptoms. But that�s exactly the point; not only is serotonin not the whole story of depression, neurotransmitters may not even be the main story.

Changes in the structure of the brain�losses of cells�are relatively permanent types of alteration. So far, there�s no evidence that such changes, once they occur�and it�s not clear when in the lifetime course of depression they set in�are reversed with drug or other therapy. And that may account for the propensity of depression to recur. "What�s less clear," Drevets says, "is why there are periods when the illness remits, then returns." But nature serves up at least one other example of disorder where there are symptom-free periods despite an enduring lesion in the brain�multiple sclerosis.

Nature, Nurture, Neuron

One of the most striking features of depression is the inability of those afflicted to see out of their rut, to imagine alternative ways of being and doing. "In depression," says Yale�s Ronald Duman, associate professor of psychiatry and pharmacology, "there�s a loss of appropriate adaptability."

Ordinarily, the neurons of the brain have an ability to change and adapt by sprouting new dentritic spines, tiny fibrous protrusions that are the primary receiving end of connections between nerve cells. By literally opening new pathways, this sprouting is what allows us to learn and to remember, to change our behavior, to meet new challenges, to adapt to new circumstances. Scientists refer to this capacity as neuronal plasticity. Depression appears to represent a failure of neuronal plasticity.

In a ground-breaking study, Duman has tracked the inside operations of nerve cells and found evidence that the depressed have a deficit in specific nerve growth factors, the substances that make possible the sprouting of new nerve cell connections. He has implicated a reduction in brain-derived neurotrophic factor (BDNF), a nerve growth factor specifically known to strengthen synaptic connections in the hippocampus (a center of learning and memory) and to enhance the growth of neurons that respond to serotonin

Duman�s studies also show that, yet again, how antidepressant agents are believed to work and what actually accounts for their effectiveness may be two different things. Long-term antidepressant treatments�including electroshock� do increase levels of receptors for serotonin at the cell surface. But, Duman has found, they also do something else inside the neuron that may be more important. They kick off a cascade of molecular steps that winds up amplifying a neuron�s own production of BDNF�and the sprouting of new connections. Moreover, they do this in parts of the brain that have been linked to depression, such as the hippocampus. The real power of antidepressants, then, may be summed up in two words: neuronal plasticity.

The molecular cascade Duman has exposed opens up a whole new realm of possibilities for improving treatment of depression. It may be possible to create therapies that more directly and more strongly augment BDNF output. At the same time, the molecular pathway culminating in BDNF production suggests new target points for a more rapid-acting treatment of depression.

What has Duman and others excited is that his evidence that neuronal plasticity is at stake in depression fits with imaging studies showing that structural changes are taking place in the brain of the depressed. The two strands of information suggest a way that depression might originate. In a word: stress.

New Stress on Stress

"There is elegant work showing that stress, whether environmental or social, actually changes the shape, size and number of neurons in the hippocampus," says Duman. "There are studies showing that stress decreases levels of BDNF. It�s a really hot area of research right now." And right at its epicenter is Bruce McEwen, head of the neurobiology laboratory at Rockefeller and of the MacArthur Foundation work group on the relationship of socioeconomic status and health.

In the lab, McEwen  is studying what happens in the adult brain of animals undergoing various forms of repeated stress. He�s looking in the hippocampus. Imaging studies have shown that this area, like the prefrontal cortex and, more recently, the amygdala, shrinks in people with recurrent depression.

Although it is, he says, "just the tip of the iceberg," the hippocampus is the region of the depression circuit that has been best studied�and linked longest to stress. In the past decade studies have shown that prolonged stress kills hippocampal cells, precipitating cognitive decline.

McEwen himself has documented that several different kinds of stress�including the psychosocial stress of being a subordinate among group-living animals, the stress of being physically restrained from moving about�can cause hippocampal cells to atrophy and retract their dendrites, presumably to make fewer connections. Others have found the same effects on animals from the stress of social isolation and, among infants, even spells of deprivation of maternal care. McEwen  has also found that stress can suppress nerve cell growth in a part of the hippocampus just recently shown to be able to renew nerve cells in adult life.  He�s trying to nail down what is cause and what is effect.

"So far," McEwen offers, "all we know about depression and atrophy of these brain structures is that it�s seen in people who have a long history of recurrent depressive illness, which may be a neurodegenerative disease. It may be that those changes can not be reversed."
However, they may be preventable earlier on in the course of depression, by timely use of an appropriate drug. "We�ve begun to look at this, reports Yale�s Ronald Duman. ""And we have found that antidepressant treatments are in fact able to induce the genesis of neurons."

Freud 1, Neurobiology 1

For many neurobiologists, behavioral plasticity is only half the new story on depression. The other part is the degree to which early experience can establish a whole lifelong pattern of brain activity. New research both in animals and in people demonstrates that stress early in life permanently sensitizes neurons and receptors throughout the central nervous system so that they perpetually overrespond to stress.

At the most recent meeting of the Society for Neuroscience, for example, research psychologist Christine Heim, Ph.D., reported that sexual abuse in girls before puberty creates hyperactivity of the stress-hormone system headquartered in the brain�s hypothalamus. And that makes them subject to depression as adults. "This is the first human study to report persistent changes in the reactivity of the hypothalamus-pituitary-adrenal axis among adult survivors of early trauma," she points out.

Heim so far has studied eight depressed women with a documented history of childhood abuse, seven women who also experienced childhood abuse but who do not have depression, and seven control women who were never exposed to such early life stress and who have never been depressed. In the neurobiology lab at Emory University, she tracked the chemical footprints of stress reactivity, in both brain and body, in all 22 women after applying mild stress�assigning them to make a brief speech and perform mental arithmetic in front of a small audience.

Normally, when a threat to physical or psychological well-being is detected, the hypothalamus amplifies production of corticotropin-releasing factor (CRF), which induces the pituitary gland to secrete ACTH, which then instructs the adrenal glands to step up production of cortisol. Early trauma, Heim found, leads to chronic overactivation of the system. CRF, many researchers are finding, acts of various brain sites to create the symptoms of depression.
All of the women who experienced early trauma reacted to the experimental stress with elevated levels of stress hormones, although the hormone levels were highest in those with current major depression. Such studies are leading researchers to a new model of depression, one they call the diathesis-stress model. Simply put, some inherited factor�maybe a flawed gene for BDNF, or individual differences in PFC activity�creates the biological vulnerability for major depression.

Then some early stressful experience�such as parental neglect or physical or sexual abuse�sets up the brain to permanently overreact to environmental pressures. Then even small degrees of later stress provoke an outpouring of stress hormones, such as CRF and cortisol, throughout the brain (and body).

These hormones act directly on multiple sites to produce the behavioral symptoms of depression�the vegetative state, the sleep disturbances, the cognitive dullness, the loss of pleasure. They push the amygdala into overdrive, churning out the negative emotions that steer the depression�s severity and add a twist of anxiety. And, as if that weren�t enough, they magnify the effects of the neurotransmitter glutamate so that it overstimulates neurons until their dendrites collapse and shrink up.

The moral of the story: Early life experience counts. Not because it creates oral fixations or other such fictions. It shapes wiring patterns in the brain and sets the sensitivity of the molecular machinery, such as production of nerve growth factors, behind nerve-cell operations.

It�s Not All In the Head

While disparate biological changes suggest that there are different types of depressions�some seeming to arise spontaneously from within, others reflecting heightened reactivity to life events�all depression is more than an affliction from the neck up. It is a whole-body disorder.

At Columbia University, where he is a professor of psychiatry, Alexander Glassman, M.D., had been studying the cardiac effects of antidepressant drugs when reports began to trickle in confirming what he had suspected�that depression makes heart disease particularly deadly. But it wasn�t clear how much of a role cigarette smoking played; the depressed are especially apt to smoke, and smoking leads to heart disease.

So Glassman teamed up with epidemiologists following thousands of people for over a decade. In 1993 the group reported that, even after they controlled for smoking, depression essentially multiplies the malignity of heart disease, substantially increasing the risk of sudden death within the next year. The report dropped an even bigger bombshell; it showed that healthy  people who are struck by depression are more likely  than their counterparts without the mental ailment  to develop heart disease about 10 years down the road. Just because they once got depressed.

 "There are two things we can say without any hesitancy," says Glassman. "If you�re 45, in perfect health, and depressed, you�re somewhere between 50% and 100% more likely to have a heart attack than if you weren�t depressed. That�s big. And if you have a heart attack and then get depressed, whether you simply get some symptoms of depression or the full diagnosis, over the next 18 months you are three and a half times more likely to die. That�s even bigger."

The numbers add up. There are roughly 500,000 heart attacks a year in the U.S. And 20% of heart attack victims develop depression.
What puts the head and the heart on a collision course are, likely, blood platelets, which play a key role in the propensity of blood to form clots. Platelets turn out to be stickier in those who are depressed. At Emory University in Atlanta, home of one of the world�s leading neurobiology labs, Dominique Musselman, M.D., has shown that the platelets of depressed people are hair-trigger responsive to activation signals, aggregating when they should be flowing.

A decade ago, the thinking was that heart attacks occurred when cholesterol-laden plaques formed on coronary artery walls and, over time, grew large enough to block blood flow in the artery. Today it�s known that heart attacks occur only when a crack develops in the artery lining that covers the slow-growing plaque. Then platelets are suddenly drawn to the site, where they adhere to the exposed artery wall and rope in even more platelets. Clotting occurs within minutes, choking off blood flow to the heart.

Bones of Contention

The somatic changes of psychological depression go bone deep. Literally. The hormonal abnormalities that mark the disorder, particularly elevated body levels of cortisol produced by the adrenal glands, also rob the skeleton of calcium. The result: osteoporosis on a highly accelerated schedule.
A team of researchers at the National Institutes of Health has found that depressed premenopausal women develop bones as porous as those of postmenopausal women. And the leaching of mineral from bone persists despite treatment with antidepressant drugs.

Led by David Michaelson, M.D., the researchers reported that bone mineral density was, on average, 6% lower in the spine among 24 depressed women than among 24 controls. And in the hip, it was 10% to 14% lower among the depressed women�decrements that set women up for hip fractures.
"Once lost," Michaelson observes, "bone density is difficult to regain." It takes years, plus a modicum of physical activity and a calcium-rich diet. But it probably never returns to normal in depression, since the disorder tends to recur�and depressed people tend to be physically inactive and eat poorly.
It�s not that chronic depression doesn�t create a huge psychological burden. But it�s becoming increasingly clear, says Columbia�s Glassman, that "depression is an illness with very real and dangerous physical concomitants."

Sick, Not Sad?

The new corporeality of "mental" illness is perhaps most daringly embodied in the work of Bruce Charlton, M.D., a research psychiatrist in the department of psychology at the University of Newcastle in England. Depression, Charlton provocatively contends, doesn�t just have physical concomitants; it is wholly a physical disorder, one that is misinterpreted by the brain. Sickness is read as sadness.

The low mood is a secondary response, a product of physical malaise, the same malaise�the lack of energy, sleepiness, slowness of movement, lack of pleasurable appetites (including sex), inability to concentrate and think clearly�one gets when, say, the flu strikes. "The trouble with malaise is that you don't necessarily know you've got it, and you blame yourself for your condition of low performance," he says.

But it is the body�s way of withdrawing (think of a wounded animal) to conserve energy and minimize risk, an "evolved pattern of behavior" mediated by the immune system. "In fact," he says, "major depressive disorder is sickness behavior inappropriately activated and sustained."

Charlton subscribes to the model of emotions put forth by the University of Iowa�s Antonio Damasio, M.D.�that feelings are the brain�s representation of what�s going on in the body. But, he says, sadness and happiness do not correspond to specific body states. Instead, they are "catch-all names given to aversive and gratifying states, end products of more primary emotions."

Still, the prevailing body state, the malaise, colors all incoming perceptions and stamps them "aversive" as they are encoded in memory. Recall, then, summons up malaise, as does thinking about the future. To the extent the malaise continues, patients are stuck, unable to even imagine anything that makes them feel motivated and energetic. Bleakness! Despair! Depression!

According to this view, antidepressants, notably the tricyclics, possibly Prozac, probably work to the degree that they are analgesics! "Antidepressants do not make people happy," Charlton insists. They treat the malaise, the state of unpleasantness. In so doing they "remove a significant obstacle to happiness. The effect of antidepressants on mood is no more remarkable than the fact that it is easier to be happy without a headache." Imagine�aspirin as a remedy for the blues!

Charlton is not alone in disputing the way antidepressant drugs are believed to work. British psychiatrist David Healy, a card-carrying psychopharmacologist, in his book The Antidepressant Era  (Harvard, 1998) contends that these agents are falsely presented as specific to depression. The idea that depression is a single specific disorder, Healy says, was created  largely by drug companies with a product�antidepressants�to sell. He argues instead that "depression" is even more than a disorder of the whole body; it�s a disorder of the whole person, existential or social distress marked by unhappiness and hopelessness. It is cast into physical symptoms�precisely because they have been made fashionable, sanctioned and publicized by today�s medical-industrial complex.

Therapy: Stripped Down and Revved Up

While debate has raged for decades over the relative contributions of nature and nurture to creating depression, and the relative merits of drug and psychotherapy to relieve it, therapy itself is evolving in ways that eventually promise to make the old issues obsolete. Consider the case of meditation, which is now being tested as both a preventive and a treatment for depression. It isn�t specific for depression. Yet it may reverse changes in the brain that are specific to depression. Is it treatment of an organ? Or of the whole person?

At Cambridge University in England, John Teasdale, M.D., has been testing meditation on recurrently depressed persons who are currently free of the ailment. The goal is to reduce the risk of future relapse. "Our results are encouraging," Teasdale teases, refusing to say more until his study report is accepted for publication in a scholarly journal.

In the U.S., Wisconsin�s Richard Davidson is also testing meditation, in this case measuring its effects on brain function. He is specifically looking to see whether it activates the left PFC or deactivates the right PFC, or both.

Two other new therapies, both inventions of the mid-1990s, are essentially adaptations of earlier treatments. And both, like meditation, have a stripped-down, tightly focused quality.

One is transcranial magnetic stimulation (TMS), a vastly defanged cousin of the extreme yet often-effective electroconvulsive therapy. In TMS, a hand-held electromagnetic coil is placed on the scalp and a series of tiny pulses are released that prompt the cortical neurons directly underneath to fire. In one placebo-controlled study, where TMS was applied over the left prefrontal cortex in daily 20-minute sessions for two weeks, patients experienced a measureable lessening of depressive symptoms.

The therapy is too new for researchers to know yet what the best dose is, exactly where to apply the current and how often. But they are confident it causes no side effects. There are no convulsions, no loss of consciousness, no memory gaps�just a tiny tingle. It is now being tested around the country as an outpatient treatment for both unipolar and bipolar depression.

At the National Institute of Mental Health, where researchers first developed the technique as "a neuropsychiatric tool for the 21st century," investigators have found that TMS produces changes in brain hormones suggestive of a tamping down of hypothalamic overactivity. But its antidepressant action may have more to do with the possibility that the treatment stimulates neuronal plasticity; researchers now know that is what ECT does, forging the connections from one nerve cell to the next that allow for behavioral change.

Behavioral change is the unambiguous goal of behavioral activation (BA), a treatment developed by psychologist Neil S. Jacobson, Ph.D. It turns clients�he rejects the term  "patients" and all "defect" models of depression, whether the defect is in brain chemistry or patterns of thinking�into miniscientists, prompting them to observe and identify aspects of their daily life that influence mood, to set workable goals, then to make small changes on a daily basis, acquiring the skills they need to solve their own life problems.

"BA takes a contextual view of depression," says Jacobson, professor of psychology at the University of Washington. It sees depression as a signal that "something is awry in the person�s life, that what is wrong is the life and not the person." BA helps people avoid making things worse by retreating from the world, "something that�s natural to do when you�re feeling depressed" but that cuts off needed sources of pleasure.

In a study of 149 depressed persons, BA proved as effectve as full-blown cognitve therapy in reducing depressive symptoms.  Although it didn't even
attempt to alter clients� thinking, BA  nevertheless decreased negative thinking. It significantly lowered clients� tendencies to attribute problems or negative events to factors that are internal as opposed to situational ("I�m stupid."), enduring ("I  was born this way."), and all-encompassing (I can�t do anything right.")�attributional styles that catapult people into depression.

Having performed as well as cognitive therapy, BA has now been put to the test against an antidepressant drug, the SSRI Paxil. "Our current trial is looking even better than the last one," Jacobson confides. "BA is working better in the short run and at least as well as Paxil." Long-term data, however, aren�t in yet.

Jacobson has his fingers crossed. "Antidepressants can be more of a problem than a solution, because at times when people feel good they lose their motivation to change their lives. When the drug effect wears off, as it does eventually, they still have the same life problems."

Plasticity Regained

Whatever pathways depression takes through the brain and the body, it is still experienced by sufferers as a disorder of the whole person, which is why its pain has always been so hard to locate. As a result, how depression is seen by psychologists and psychiatrists, how they explain it to you and me, and how patients understand their own disorder�all influence not only what symptoms patients complain of, but what they are willing to do about them.

Fashions in thinking about depression make a measurable difference to recovery. "We have, before applying standard treatments, looked at clients� theories of why they are depressed," reports Michael Addis, Ph.D., a psychologist now at Clark University in Worcester, Massachusetts, who studied with Jacobson�s group in Seattle. "Their theories are predictive of the outcome of treatment."

What is available to clients as explanation is the very stuff psychologists and psychiatrists talk about. The culture has become both more psychological-minded and more biological-minded. As a result, Addis has heard clients say things like, "My doctor said this is a chemical imbalance, so why are you talking to me about doing pleasurable activities?"

He urges professionals to understand what patients think of their own psychopathology. "We don�t know what our theories mean to individuals. We say �chemical imbalance.� To a patient that means, �I�m damned.� Our theories are not neutral."

Which is why Peter Kramer, who usually prescribes both psychotherapy and drug therapy, ponders "which is the umbrella concept?" Is the brain a biological organ and psychotherapy another way to influence the brain? This is the view the field of psychiatry is moving towards.

Or is drug therapy an adjunct to psychotherapy? "This is my model," he says. "Medication is one way of helping patients broaden their perspective." In other words, it�s a way to restore what makes people most human�our remarkable capacity for meeting life�s ever-changing demands.
 

Copyright 1999 Hara Marano.  All rights reserved.   HMarano@aol.com

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