Medicine's Silent Threat

A silent, hidden threat continues to gain power in our nations medical apparatus. It is

threat which makes no sound, is completely invisible to the eye and stimulates no

senses. Yet it’s power to impact human health in a profound and powerful way is clear

and undisputed. The name of this threat is Ionizing Radiation.

There are several types of radiation found in nature, but ionizing radiation remains

notable for it’s ability to damage human genetic material and exert physiologic effects in

the body. In an era when medical imaging is routine and as accessible to this

generation of physicians as stethoscopes and reflex hammers were to previous ones,

the problem of medical radiation remains an unseen but deadly manifestation of modern

medicine.

The story is one which plays out thousands of times a day in every hospital, clinic and

emergency room in the developed world. A patient presents with a nebulous medical

complaint and the physician taking care for them must answer a critical question:

Should this person undergo medical imaging or not. This decision might not be so

vexing were it not for the long list of harms and benefits that accompany it. It is

estimated that ionizing radiation from medical imagining now accounts for half the

overall radiation exposure in the US each year.

While some medical imaging studies offer harmless non ionizing radiation (like MRI) or

small doses of harmful ionizing radiation (X-ray) among the most widely used imaging

studies is the CT scan which gives a massive dose of ionizing radiation. A single CT

scan provides more ionizing radiation than 200 Chest X-Rays. Despite the radiation exposure, CT scanning remains increasingly among popular among physicians with use of the CT scanner growing exponentially over the past several decades. It is estimated that use of CT scanning in the United States has tripled since 1993.

The effects of all this radiation on the population is far from miniscule. Studies

estimate that the lifetime radiation dose of a few CT scans (how many depends on

which part of the body is being scanned) is comparable amount of ionizing radiation to

being in Hiroshima on the day the atomic bomb went off. One particularly controversial

study estimated that 1.5-2% of all future cancers in the United States will be because of

medical radiation. Another study estimated that CT scanning increase any one

individuals risk of cancer by .35% and while this may not sound like much on a

population level that would translate into tens of thousands of cases of cancer per year.

In fact another study estimated 29000 cases of cancer caused by CT scans done in

2007 alone.

And yet The CAT scan has changed the way medicine is practiced. It was not long ago

when physicians had to rely on history and physical exam to make the diagnosis. CAT

scans gave physicians an accurate, objective way of seeing exactly what was

happening inside our patients that exceeded the power of our own senses.

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Anyone who has ever practiced medicine understands that the idea behind any medical

intervention is that the therapeutic benefits of doing something that could cause harm

outweigh the risks. The same rules should apply to CT scanning. There are many

indications where the relatively small individual increased risk of cancer from giving a

CT scan is outweighed by the benefit of making a diagnosis, confirming suspicions and

governing treatment.

The problem is that the CT scanner is being used too much and it is contributing to a public

health crisis. Studies estimate that 30% percent of CT scans are not needed and I

believe that is an underestimate. All those unneeded scans are creating exposure to a harmful, but invisible, toxin. If a newly discovered environmental toxin in our food or water was noted to cause almost enough cases of cancer to fill a baseball stadium every year it would be all over our televisions, newspapers and webpages. Should we not hold modern medicine to the same standard?

A few months ago my 6 year old nephew George fell about 12 feet and landed on the ground head first at a family party on rock hard pavement. He was rushed to the emergency room and

even though he was conscious and appeared well he was given a CT scan. The reason

for this was that George’s mechanism of injury was deemed “high risk” and therefore

the CT scan was indicated. His scan was normal and all the adults left the Emergency

Room feeling better that day, reassured that Georgie did not have bleeding inside his

brain. Georgie and his family will have to live with the increased risk of cancer but

overwhelming odds are he will not get cancer from his CT scan.

But George’s situation was black and white. George needed the scan because his fall

was high risk and the good outweighed the bad. When the situations are black and

white decisions are easy to make. When situations are grey things gets tricky. What

if instead of falling from 12 feet he fell from only 4 feet? And what if instead of

absorbing the blow only in his head Georgie had a second injury on his arm indicating

that it had absorbed some of the force of the fall? Georgie would have been in a grey

area under those circumstances. Physicians today who find themselves in those “grey

areas” are relying on CAT scanning to help them figure things out. It

reassures physicians and patients but the costs are tremendous: we are creating tens of

thousands of cancer patients per year. This is the definition of a public health

emergency.

Studies have been done and there are clear evidence based rules that tell doctors when

to use CAT scans to image heads, necks, abdomen and chests. Physicians should be

conscious of the harms of CT scan and the price of getting definite answers and try to

stick to these rules in the context of their own judgement.

The risk is one physicians must take at times, but unnecessary CAT scans are causing disease and we all took an oath to do no harm. When physicians minimize patient harm and rely on evidence based rules to form the backbone of their decision making and help them decide when to use the CT scan then they will  be making decisions that benefit patients and truly doing no harm.

The Chest Cracker Diet and Why the Heart Disease and High Cholesterol Epidemic Makes Perfect Sense to Me

Heart disease is one of the leading killers of Americans and I can see why.

  

Much attention has been placed on prevention of cardiovascular disease in this country and on identifying and controlling risk factors for it. Among the many known cardiovascular risk factors cholesterol is important both for it’s powerful impact on the development of heart disease and in it’s capacity to be modified by medical and lifestyle interventions.   Based on the American diet the cholesterol and heart disease epidemic we are experiencing makes perfect sense.

 

 

About one million Americans die each year from heart disease.  A persons cholesterol level is important to the development of heart disease because of cholesterol's ability to strongly contribute to the process of developing plaques in blood vessels. The presence of these plaques increases the chance that someone will experience heart disease.  A major culprit in this process lies in something that is probably in the kitchen and on the plate every day of almost every person who is reading this: Meat.  

Scientists search for the solution to heart disease and high cholesterol in laboratories with pills and physicians crack open about 250,000 chests each year to try to fix the hearts of Americans who have developed severe heart disease. All the while the cholesterol epidemic rages on as currently it is estimated that over 50 million Americans have high cholesterol.

But the cholesterol epidemic we are experiencing now is no mystery and the most powerful solution is not pills or surgery. A close look at what and how most Americans eat reveals that the cholesterol epidemic is a logical consequence of our cultural beliefs around nutrition and especially eating meat.

 

 

The bottom line is that Americans eat far too much meat per year and it is literally killing us. Every year the typical American eats an artery clogging 260 lbs. of meat per year (that breaks down to about 12 ounces of meat per day) which is the world's highest rate. According to the United Nations that is about 1.5 times the industrial world average, three times the East Asian average, and 40 times the average in Bangladesh .

 

Meat is a problem because ALL meat is high in cholesterol, including white meats like chicken and turkey. I want to repeat that because it is a MAJOR misconception among most Americans: White meats like Chicken, turkey, pork and even fish are all loaded with artery clogging cholesterol and have a comparable amount of cholesterol to red meat. White meats usually (but not always) have less dietary fat and that is why they are considered healthier than red meats but it has nothing to do with cholesterol.

 

How meat contributes to our cholesterol problem is two fold. It is part of our culture to eat meat with every meal. Most Americans don’t feel like they are having a “real” meal if it doesn’t involve meat. Therefore most Americans eat meat several times a day with every meal. Secondly the typical American portion of meat is insanely large. Even a pro-meat nutritionist would advise only a 3.5 ounce portion of meat with a meal (about the size of a deck of cards), but the typical American portion of meat at home or in a restaurant in usually around 12 ounces per meal or 3-4 times what is recomended in a serving.

 

It is important to note that some cholesterol is an essential part of a healthy diet. The ADA advises most Americans to have between 200-300 mg of cholesterol per day to maintain normal bodily function. But the typical American diet dwarfs that amount.

 

Just do the math. A 3 ounce serving of any meat has around 70mg of cholesterol depending on the cut. If, as the U.N reported, the average American person eats 12 ounces of meat per day than that person will have nearly met their daily requirement for cholesterol just from meat alone in a typical day. Now add on all the other cholesterol from other non meat foods comprising a full diet of 3 or 4 meals and 3 snacks each and every day over the course of decades of life and it is quite logical why over 50 million Americans have high cholesterol and our nation is suffering a cholesterol epidemic.

 

Doctors have good medicines that can help combat high cholesterol, but this is like using a band aid to cover a major wound. The real problem is in the dietary traditions of Americans. Americans choose to eat too much too often and that is why we struggle to control cholesterol levels.   American need to change the way they think about food.    

The typical American meat heavy diet should be called “The Chest Cracker’s Diet” because it leads to hundreds of thousands of chests getting cracked open every year among unfortunate, genetically predisposed individuals who develop severe heart disease. Meat eating is often categorized as being manly in the popular media but trust me there is nothing strong or masculine about heart disease or Coronary Artery Bypass Grafting.  Occasionally eating meat is probably alright (I would say one small 4 ounce portion every2-3 days) but as long as Americans insist on following the myth that massive slabs of any kind of meat must be a part of every meal than we will continue to suffer from a cholesterol epidemic and experience alarming death rates from premature heart disease.

Is It Right For Physicians To Take A Parental Role With Patients?

A pair of recent studies looked at different modalities for following patients on weight loss programs. One study compared patients who received  in person follow up from primary care providers versus those who received telephone and web based follow up to those who got nothing at all.  Patients in either follow up group experienced twice as much weight loss after one year than those who had no follow up at all (there was no difference between either follow up intervention).  The other study looked at the effectiveness of in-person “life coaching” on weight loss results and also found it to be significant. 

While the impact of this in terms of weight loss indeed could be huge I also believe this study raises an interesting question about doctor patient relationships and boundaries that is worth exploring.

The overall message of the studies was that patients in both groups who had any kind of follow up with their primary care providers (be it in person, on the phone or web based) experienced better results in losing and maintaining weight than those who did not.  With 2/3’s of Americans overweight or obese, any intervention that can help patients maintain weight loss has the ability to improve millions of lives and should therefore be utilized. The authors hailed the study as a breakthrough in helping patients battle obesity.

“It could be considered something of a breakthrough in weight loss,” said Dr. Frank Sacks, a professor of Cardiovascular Epidemiology at the Harvard School of Public Health who participated in the second study.

While this intervention may be effective in the laboratory the question remains about how this impacts doctor patient relationships in the clinic and if this impact is ethical or fair?  If adult patients are reporting their weight loss to physicians does this not place the physician in a paternalistic or parental role to the patient and if so is it appropriate for doctors to take advantage of this role in clinical practice?   

The hidden dynamic among all human relationships, and especially those between doctors and patients, is a phenomenon called transference.  Transference is the process whereby one individuals unconscious emotional perceptions influences their participation and behavior in a relationship.  The perceptions are usually very powerfully influenced by early childhood influences.

For example a person who had a poor relationship with little verbal communication with a male caretaker early in life may have a difficult time communicating with other male authority figures later in adulthood.  

Transference is classically thought of as a part of psychiatry and psychotherapy, but all doctor patient relationships (and all human relationships) are deeply influenced by the unconscious subjective perceptions of the participants. 

In my coursework with the New England Society of Clinical Hypnosis I will never forget the words of the brilliant hypnotist  and former NESCH president Dr. Max Shapiro who surprised me in a seminar many years ago when he said: “If a patient comes to you with a deific or mystical transference  about hypnosis don’t be afraid to use that in your work with them.”  

Shapiro felt that using the patients unconscious feelings of awe or mysticism around hypnosis (which is often held in such mystical esteem) to their  advantage could be a useful intervention towards reducing symptoms and improving their lives.  Could the same be argued in this situation regarding a patients parental transference to the physician? 

The doctor patient relationship already intrinsically has a parent child tinge to it by it’s inherent nature.  Consider the things that physicians typically provide to patients.  Empathy.  Nurturing.  Moral, emotional and physical guidance.  The very essence of the relationship evokes a parent-child dynamic between the doctor and provider that is unavoidable.

When patients report their progress in weight loss to the doctors does this not place the physician even more in a parental role with the patient?   The physician becomes the source of praise and approval or of disappointment and disapproval like a parent around a critical issue in the patient’s life.  This takes advantage of the parental transference-countertransference between the doctor and the patient and may produce results but is it appropriate?.  Consider that patients with serious behavioral health problems often lack psychological maturity in some way.

There are no right or wrong answers to this question but it is worth thinking about: Should physicians be placing themselves in a position where they can take advantage of the parental transference countertransference dynamic that exists between them and their patients?    It could produce results but is it ethical and fair to adult patients who ultimately would be best served by empowering themselves to ensure their own wellness without reliance on a professional’s praise or approval?  Could taking on a parental role with a patient eventually provoke feelings of rebellion and disobedience (often a part of parent-child relationships) that may undermine the purpose of the intervention eventually?   Should doctors dare to take advantage of this mechanism in patients who lack psychological maturity?

It is likely that right or wrong these interventions will become more widely used because of the results they showed in these studies but I believe these are important questions to ask.  

A Fundamental Flaw In Modern Psychiatry?

There is no question that as modern psychiatry has evolved it has become a powerful force in the United States.

The field underwent a major shift in paradigm the past 30 years.  Psychiatrists used to work mainly with behavioral modalities like different kinds of therapy to encourage self exploration and change, but modern psychiatry has focused on the use of powerful psychoactive drugs to alter behavior.  Psychiatrists previously spent hours in therapy with their patients but today most psychiatrists get less training in therapy in residency and in clinical practice usually only do 15 minute medication visits with patients.  In these visits they prescribe powerful medicines and inquire about side effects from drugs and leave the therapy to psychologists and social workers.  

Psychiatrists have left the therapy couch behind and transitioned mostly to drug based therapies based on the idea of biological psychiatry.  This is the basic concept that a "chemical imbalance in the brain" can be treated with a "precisely tailored" medicine.  While this concept sounds great in advertisements and commercials a closer look shows that the science is behind these "chemical imbalances" is not well defined and the drugs used are hardly precise and often have bad side effects.

The true causes of psychiatric illness goes beyond a simplified chemical imbalance and remains a nebulous combination of psychological, environmental and biological factors that probably varies tremendously among individuals.   The danger is that in actual clinical practice the treatment option most individuals get now from doctors is a drug that alters brain chemistry in a very imprecise way, but mental problems happen on many different levels.

These underlying chemical imbalances may not be well defined in mental illness, but psychiatric drugs have a place in medicine and if a doctor prescribes one a patient should NEVER stop taking it until they have an in depth conversation with the prescriber.   

As this paradigm shift has happened physicians are confronted with the danger of not considering the depth and complexity of most behavioral problems for the individual.  Advertisements and commercials make these drugs sound simple and many doctors place patients on these drugs without much thought, but be advised: Psychiatric drugs are complicated and have serious pros and cons that must be carefully considered.  The decision to start one should never be taken lightly or glanced over.

There is no doubt that part of mental illness is biology.  There are clearly functional, physiological and anatomical changes in the biology of the brain that are associated with different acute and chronic mental and emotional states.  Yet there is murky evidence that any of the biological mechanisms altered by psychoactive drugs actually cause  the "diseases" these drugs treat.  Altering these mechanisms may help change symptoms much like tylenol helps a back ache but that doesn't mean deficiency or disorder in these areas cause clinical disease.  After all, no one would argue that a lack of Tylenol causes backache. 

As Modern Psychiatry has become overly reliant and focused on drug therapy it has lost sight of the human side of behavior. It has stopped seeing the "forest for the trees" and forgotten that every illness occurs in the context of social, cultural, behavioral and psycho-spiritual factors, not simply biology.    Medicine and Psychiatry often try to drug people to meet our arbitrary cultural standards of normal and abnormal (and disease and health), when often the emotional and behavioral states of individuals are natural to that individual, appropriate based on circumstances and have potential for positive change through non-pharmacologial, human centered modalities.   

In a perfect world much thought would be given to the decision to start high functioning adults on any psychoactive medicine.  These drugs would not be routinely handed out with minimal consideration of the whole person's body, mind and spirit.   And the paradigms that doctors use to view behavioral problems would address the existential roots of human problems.


 Over the next few weeks we will present a series of topics in modern psychiatry where we look specifically at the pro and cons of drugs, investigate the science behind behavior and hopefully provide useful information to help people understand modern psychiatry better. The first topic is going to be on antidepressant use so stay tuned! 

Are People Who Take Vitamins More Likely To Die?

A recent study in the Archives of Internal Medicine has added fuel to the debate regarding vitamin use in healthy adults .  The study showed that vitamin users were more likely to die of any cause over several decades than non vitamin users.

The past several years has seen several journal articles about vitamins and minerals that have provided a wide array of information about their use to the general public.  The information these studies have given usually has been confusing, vague, often contradictory and the result of study methods that are confounded.    The general message of these studies has been that vitamins have not been proven to have great health benefits to healthy adults and may in fact be harmful.  This study does little to add concrete information to the debate about the benefits or harms of vitamin use.  The same questions that existed about vitamins last month persist today. 

 

 

Medicine still doesn't really now much about the long term use of vitamins in healthy adults and the debate rages on about what the effects actually are. As the authors of the recent paper pointed out "Although dietary supplements are commonly taken to prevent chronic disease, the long term consequences of many compounds are unknown."

This particular study looked at a large group of woman from Iowa over several decades to assess what if any relationship vitamin use had on the woman's overall mortality.  Data was collected on over 40,000 woman who completed surveys regarding vitamin use in 1986,1997 and 2004.    The results seemed to carry a daunting message regarding vitamin use. All the vitamins and minerals studied (with one exception) were associated with a higher risk of all cause mortality.


Specifically the authors looked at Multivitamins, Folate, B12, B6, Magnesium, Zinc, Copper, Iron and Calcium. Of these only Calcium use was associated with a lower rate of mortality. All the other vitamins studied showed an increased rate of death.  The magnitude of the association in all cases was small but statistically significant.


So healthy adults are again deluged with another piece of information about vitamin use and are left to wonder if vitamins are associated with a increased risk of death and if healthy adults should stop taking vitamins?


Before we can assess this we need to look at the old paradox of association and causation. We can't assume that the association we see in this study is because vitamins somehow contributed to early death. A very likely explanation for some or all of these findings observed is that people who take vitamins are generally at baseline less healthy and more likely to have chronic disease than those who don't. By studying vitamin users the authors selected a group of patients who were by definition sicker and more likely to die than the general public for reasons that had nothing to do with vitamins.

It is imporant to note the authors did correct for Cardiovascular Disease and Diabetes in the results and the observed association held up. However they did not correct for many other chronic diseases that make people more likely to die and may also lead to vitamin and supplement use such as kidney disease, cancer, anemia, HIV, mental illness and many, many other medical problems.  

We can use iron as an example of the flaws in this study.  If you read the paper you will notice the strongest association the authors found is between iron supplemention and death rates. They even found a dose response relationship between iron and death rates, with the highest doses of iron leading to a 65 percent increase in death risk.  Does this mean iron is a dangerous thing to take? 


As always the true answer is unclear. Iron may contribute to mortality but some of the sickest individuals in the world today are on very high doses of iron because of severe chronic illness leading to low blood counts.   The authors speculate that perhaps iron leads to some "pro oxidative" state that contributes to disease and explains the results.  To me this is complete speculation and almost irresponsible to put in a paper. It may be worth investigating if iron causes disease and death based on these results, but it is hardly the most likely explanation.  The most likely explanation for why this study showed an association between iron use and death rates is that very sick people are often advised to take iron to help manage chronic, debilitating disease (because of low blood cell counts). It should not be a suprise to anyone that more of those people died over 2 decades of follow up.   I would expect to find similar relationships contributing to  (but not neccesarily invalidating) the observed results for all the vitamins and supplements looked at, including calcium which showed a beneficial effect on death rates

So where does this leave us for vitamin use? Can we completely ignore these results because the methodology of the study was questionable?  



While there is no doubt that vitamin use has been shown to be helpful in specific medical conditions (such as Vitamin D and Calcium preventing osteorporosis in at risk individuals) for the general public if you don't fall into a specific group that needs to take a vitamin or supplement for a medical reason than the wisdom of taking vitamins is questionable.  More and more research has failed to find a health benefit to vitamin use in healthy adults (including this study) and some have shown a potential harm.

It is possible that all the studies showing harms of vitamins had such flawed methodologies that they actually masked a truly beneficial relationship for vitamin use in healthy adults but this is unlikely.  It seems more plausible that evidence supporting benefits to vitamin use in healthy adults without medical problems is scarce and the harms may be real.   There are specific medical conditions where vitamins are definitely beneficial but until more is known healthy adults should have conversation with their physician about if vitamin use is appropriate for them.

What Creates a Back Injury?

Lower back pain remains a common and debilitating problem for many Americans because of it's ability to cause discomfort and disability in those who experience it.

Any significant  back pain requires a medical evaluation because of the uncommon possibility of a serious problem but most back pain is caused by injury to the muscles and joints of the lower back. 

Because of the association between certain high risk occupations and back pain The National Institute of Occupational Health and Safety has investigated the conditions that create these injuries by studying the forces that act on the lower back to cause injury.  In doing so they give an important message to the general public about how to prevent back injuries.

What NIOSH has found is that individuals who develop back injuries do so usually because they place chronic repetitive forces over long lengths of time on the joints, bones and muscles of the back. 

NIOSH analyzed the process and found that three major forces act on the lower back during movement and lifting.  These forces consist of a rotational force and a compressive (downward) force on the muscles and joints from the weight of and technique used for the object lifted and the force of the individuals own upper body weight acting down on the muscles and spine during each act of  movement and lifting. 

NIOSH has adopted a complicated equation to describe these forces at play in occupational activities and to calculate them in order to prevent occupational lifting from exceeding forces that human backs can tolerate. For the purposes of understanding back injuries we don't need to crunch numbers or understand any math to see the take home message is that the forces that act on our lower back are proportional to what we lift, how we lift it and (quite importantly) how much force our own upper body weight exerts on our on back with every act of lifting or movement.

The NIOSH lifting equation shows that our own upper body weight is a big part of the repetitive forces exerting impact on our lower back muscles and spine. Every time we lift something or move we are putting a force down on our back that is proportional to our own upper body weight.

As Americans gain more and more weight it makes sense that lower back pain is among the most common chief complaint to doctor's offices. It is estimated that as many as 70-80 percent of adults will experience lower back pain at some point in life.

When the chronic repetitive forces on the back muscles and joints exceed the ability of body to heal itself injury develops.  NIOSH learned that cases of back pain are often preventable by reducing the impact of these chronic repetitve forces on the back muscles and joints and enacted rules to limit what and how much can be lifted in the workplace.  For most Americans who don't work in jobs that require repetitive lifting of objects excessive body weight is the main culprit in the development of chronic repetitive forces on the back.

Weight loss can reduce the magnitude of forces acting on our spinal joints.   In a country where it has become normal to be overweight or obese back injuries are becoming more and more of a problem.  By remaining at an appropriate weight people can minimize the impact of forces on the lower back.

The Western lifestyle is a medically dangerous endeavor that is creating many health problems for individuals that modern medicine can not overcome.  As individuals enter into a viscous cycle of poor nutrition, sedentary living, weight gain and stress medical problems are sure to follow. We can see in this instance one small example of this process. We can imagine how weight gain might be the result of a sedentary life style and poor nutrition leading to increased upper body weight and increased forces on the back.  When injury develops this could be a further roadblock to activity, weight loss and better health. 

The NIOSH lifting equation, while meant to aid in management of occupational back pain, gives an important message to all with back pain and the general public.  There is yet another reason to eat right, exercise  and stay active: Controlling your body weight can reduce forces on the spine and prevent the development of lower back injury.

Not So Fast: Drinking Coffee May or May Not Protect Against Depression

The Archives of Internal Medicine recently released a study that linked reduced incidence of depression with increased coffee consumption. While the actual study only touted an "association" between coffee consumption and reduced rates of depression, the popular media took the ball and ran with these findings to present a different picture to the general public.

The headline for the link for the story on Boston.com read "Can Woman Avoid Depression by drinking Coffee?" This headline is emblematic of a long standing trend in the popular media to categorize medical research in a way that is misleading to those without medical expertise. Of course the headline isn't entirely unreasonable but to most people who merely glance at it or perhaps read a few paragraphs the message may well be "Avoid Depression" and "Drink Coffee" but this is not exactly what the study says.

In very plain English the message of the study is "We observed a group of woman and those who developed depression reported that they drank more coffee than those that did not." If you don't have a backround in science it is easy to get from that the message that "Coffee protects against depression.". Yet the difference between these ideas is subtle but critical.

It is presumptious to infer that coffee can protect against depression based on the results of this study because we don't fully understand the nature and direction of the association. The fact is the study does not offer concrete evidence into the observed relationship between coffee and depression. We can only say that for some as of yet unexplained reason, people who drink more coffee seem to have less depression than those who drink less coffee.

For all we know the association could be that coffee shops tend to be located near psychiatrists offices and people who seek psychiatric care (and therefore areless likely to develop depression) also just happen to stop for coffee when they visit their psychiatrists. It could be that people who can afford coffee come from a higher socioeconomic status or have access to better preventive treatments for depression.

Of course these explanations are somewhat ridiculous (especially considering that medical treatments for depression have questionable efficacy) but the point is clear: there are many explanations possible that could account for this association besides concluding that coffee protects against depression. For all we know coffee may actually even cause depression.

A more realistic potential snag in this study that I see is that caffeine use is not generally recommended in two important groups of people that have high rates of depression as compared to the general public. People with sleep disorders and people with anxiety disorders can not drink coffee and are told by doctors to avoid them because they worsen anxiety and insomnia symptoms. These groups also have higher a incidence of depression than the general population.

The study authors agreed with this and even commented in the article on this possibility saying "caffeine might induce sleep disturbances or insomnia or anxiogenic effects. It is possible that sleep sensitive or anxious woman are aware of the stimulatory effects and may lower their consumption accordingly." While the study did include asking the subjects to complete an index assessing mental health, it did not gather data on anxiety disorders or sleep disorders that could be controlled for in the final results.

So is the effect we see in these findings really that drinking coffee caused a reduced chance of developing depression or was it that people with other medical problems strongly associated with depression also tended to avoid coffee because it would exacerbate their symptoms of anxiety and insomnia? Or is it something else? We simply don't know.

In the past some of our best medical discoveries have come from observations such as this association. But this method has also created some of our most massive medical blunders (ever read the story of hormone replacement therapy?). Individuals should continue to be skeptical of how findings of medical evidence are presented in the popular media.

The reasonable conclusion from this study is that coffee is probably not harmful to humans and may indeed have health benefits so if one enjoys coffee they should continue to enjoy it in moderation. We can also say that coffee is associated for an unknown reason with reduced risk of developing depression, that this effect could be real but it could also be artificat (we don't know). We can definitvely say that coffee will definitely make symptoms of sleep disturbances and anxiety, often found in depressed individuals, much worse.

The take home message is that if you are interested in preventing depression you may want to hold off on buying that big bag of coffee beans, especially if you have trouble sleeping or are anxious, until further studies can be done to to explain the true nature of this association. The real danger of how studies like this are reported is it may cause someone with anxiety or insomnia, in addition to depression, to binge on coffee thereby making their anxiety/insomnia symptoms worse and that is definitely not the right thing to do in this situation.