In our last guest blog post, Linda Rice began an interview with Dr. Kurt Grady, centering primarily on the most popular psychotropic drugs. This post continues that interview, addressing the idea of chemical imbalance as a cause of depression.  You can find more of Linda’s writings here

Before we move to chemical imbalance, is there any other current trend that you’ve noticed in psychiatry?
The “hot” diagnosis these days is bipolar disorder.  Diagnoses run in parallel to what the pharmaceutical industry is promoting.  For more than a decade, depression was the prominent diagnosis as there were many companies who were promoting drugs for that condition.  TV commercials, print ads, talk shows, magazine articles…depression was everywhere.  When was the last time you saw something about depression?  When the drugs become generics, the drug companies stop promoting them and stop investing millions of dollars in advertising.  As bipolar disorder is fading, fewer drugs are coming out for new conditions.  This is largely in response to several of the major drug companies getting out of the mental health business.
I’m not sure I follow you on bipolar as hot and fading. Are you saying that bipolar is the present fad but as a diagnosis it has climaxed? 
Yes, you are correct.  In the absence of new drugs coming out for anything new and novel, bipolar is hanging on as the diagnosis de jour.  However, as you have already been seeing in the popular press, there are lots of “new” diseases coming thanks to the DSM-V.  Now, researchers (read: pharma companies) will have some new targets to look toward.  Sadly, many of these will be in people who have just normal problems of living and no causative pathology.  The cycle restarts….
A few months ago, I met someone who insisted that she had a chemical imbalance. She said that her doctor had run a blood test which indicated low serotonin levels. So a chemical imbalance was causing her depression. How would you respond to that?

Serotonin-3D-vdW (Photo credit: Wikipedia)
First, blood serotonin levels are not known to correspond to brain serotonin levels. Moreover, the assertion that serotonin is the cause of depression is, at best, a theory that is not proven in living, breathing, walking-around human beings. In addition, in order to state that there is a chemical imbalance, we must first know what the chemical balance is. In other words, we must know something about what is normal before we can determine that something is abnormal. This information is not available. We have no quantifiable data to determine the correct amount of serotonin that should be in various parts of the brain. Without that, again, stating that there is an imbalance is based on pure conjecture. Lastly, even if we could identify that serotonin was low in the junctions [synapses] between various nerve cells in the brain, it still does not mean that low serotonin is the cause of depression. Serotonin could be related to depression but to say that it is responsible for causing depression is yet again conjecture. It could very well be that low serotonin is a result of depression rather than a cause. In short, there is much quoted today about various neurotransmitters in the brain yet our understanding of how these chemicals actually work in the brain is limited. There is a great deal more that needs to be said on this topic for the general public to understand the difference between theory and certainty.
You say, “blood serotonin levels are not known to correspond to brain serotonin levels.” This is because serotonin is a molecule too large to cross the blood-brain barrier. So even if a blood test is run, the results will show only the serotonin levels in the body, not what is in the brain. Is this correct?
Yes.  Platelet serotonin does not equal brain serotonin.  there is not even a good way to correlate them in that A) we do not know for certain what serotonin really does in the brain and B) we have no way of quantifying how much serotonin is at work in a particular synapse. C) We have no way of knowing if or how brain serotonin correlates to blood serotonin. D) There are multiple receptors for serotonin and these are found throughout the body, not just in the brain.
Wouldn’t a medical doctor know this?
Well, that might depend on how much of the pop culture mental health cool aid they have been drinking….

English: REGULATION OF SEROTONIN SUPPLY IN THE BRAIN 10 (Photo credit: Wikipedia)
Now, I’ve seen websites and TV ads that explain with terms of certainty how antidepressants work. Yet, I’ve heard biblical counselors say that no one knows for certain how they work. Is it true that we can say without qualification that antidepressants prevent reuptake of serotonin in the brain and, thereby, increase brain levels of serotonin?
See above.  What we can say is that antidepressants sometimes make some people feel better. However, we must also consider that at least some of what we call depression is not an organic brain malfunction.  Often, depression is the result of a spiritual issue. This is difficult for people to accept because we do not want to be accountable for sin. Dealing with personal sin is painful in some cases and forces us to humbly confess and seek forgiveness. It is far easier to blame an alleged chemical imbalance for our feelings than to acknowledge the work of the Holy Spirit in our lives as He works on us to bring us into conformity with Christ. If this is the case, utilizing a medication may make us feel better but it fails to help us deal with the spiritual matter. In this case, God will continue to work on us and our struggles will continue.
Does this mean that it is wrong to take a medication? Certainly not. If there is a true medical problem, an alteration in the anatomy or physiology, a medication may very well help. However, medication is not the answer for every problem that assails us. Great caution should be exercised by Christian people.  Medicine today has attempted to take many of the things that Scripture calls sins and turned them into so-called diseases. Examples would be converting drunkenness to alcoholism or persistent theft into kleptomania. There are many, many others as well. Christians should be looking at life through the lens of Scripture and dealing with spiritual problems biblically and medical problems medically. Much discernment is required, especially when it comes to matters of “mental health.”
Also, it is the Package Insert (PI), not a website or infomercial, that is authoritative on that drug. The PI is the paper that comes in the package when we purchase the drug from the pharmacist. The PI discloses what the drug company itself claims as to what its researchers know or do not know about how that drug works. That information is on the PI under the heading “Clinical Pharmacology.” Is that correct?
Yes…and pay particular attention to the language therein.  Words and phrases like “thought to…  believed to be… suggested… animal models…  in vitro…(this is in “test tubes essentially) ex vivo…(this is human tissue that has been “grown” in the lab and subjected to various tests) [indicate uncertainty].
Animal models assume that what goes on in an animal brain is what goes on in a human brain and that thinking, behavior, and feelings are caused by that chemical. This line of thinking is inextricably linked to the theory of evolution as well as philosophical materialism (nothing beyond what is physical in the universe). In many of our problems, Scripture tells us that the point of origin is in the heart (immaterial man) not in the brain (material man) so many of the things the world calls “disease” and attempts to explain via biochemistry…according to Scripture, are matters of the heart first. Perhaps there are indeed chemical changes in the brain. However, these are just as likely to be the result as they are to be the cause. Applying medical solutions to immaterial man issues does not address the problem at its core: the heart of man. The key here is understanding what is heart and what is brain.
My thanks to Dr. Grady for this interview.