Following is the fourth and last segment of my interview with Ken Duckworth, M.D., the medical director of the National Alliance for the Mentally Ill (NAMI) that I was afforded through a blogger call hosted by Revolution Health.
For Part 1 click here.
For Part 2 click here.
For Part 3 click here.
To hear a podcast of the entire interview, click here.
Here, then, is the fourth and final part!

Are there any studies that have showed a connection between thyroid disturbance and depression or any brain chemical imbalances?
There are a lot of things that are interesting. There is an increased association between some endocrine problems and brain disorders. For instance, if you look at the question another way … people with bipolar illness and schizophrenia have definitely been shown to have higher rates of diabetes. I think it’s a less robust association with thyroid problems, but what’s important about thyroid problems is that the thyroid is essentially the battery that drives the car. And when a person has too little thyroid, they can really appear depressed, and when a person has too much thyroid, they can appear manic.
And there is an association between endocrine problems and brain disorders, but it’s far from perfect. That is to say most people with thyroid problems have normal brains. And most people with major mental illnesses have normal thyroids. But if you have a mental illness, you should look at your thyroid, because that’s important. And if you have a thyroid problem, you should evaluate how that can be interfering with your mental-health function, because it can.

I think all this is interesting because I found out that I had a tumor in my pituitary gland, and it seems to me that the timing of when I began to get better from my debilitating depression was when I started the medication to shrink the tumor.
Are you okay now?
Yeah. It’s small enough now that it can stay where it is, as long as it’s not growing. When you mentioned the connection between the endocrine system and mental illness, I just thought that was interesting because now I go to an endocrinologist regularly, in addition to my psychiatrist. I guess I’m just amazed at the interconnection of it all.
There are a lot of interconnections.
Yeah, there are … I was interested in your take on the work of Helen Mayberg, Professor of Psychiatry and Neurology at Emory University School of Medicine in Atlanta, Geogia, and Peter Kramer, who wrote “Against Depression“—some of these more neurological approaches to treating depression, the kind of brain circuit model. Because from what I read in a Johns Hopkins report, Mayberg is trying to treat depression from WHERE it’s causing a problem in the brain, instead from a bio-chemical, neurotransmitter model. She’s trying to locate where, specifically, Area 25 I think, in the brain where this type of black-out happens. She can tell the difference between the brain or neurocircuits of depressed people as opposed to persons who don’t suffer from depression. And with brain-imaging scans, she’s been able to detect the problem, and she thinks we will be able to treat depression more effectively if we can get these brain images.

There is no question. We need to understand more about the neurocircuits and the path of physiology of depression. Depression seems to appear around the globe, just as bipolar illness and schizophrenia do. Some health organizations believe that depression will be the number one cause of disability or lost days in the future across the world as the world gets more westernized. With this, it appears, that depression becomes a greater risk: increased mobility, less connection with other people. So understanding the roots of depression is very, very important.
What flows from this transcranial magnetic stimulation, or TMS, is looking more at a neurocircuit model. I will say that it’s an untested treatment. I never recommend that people go out and try the newest thing because it’s frequently that you learn about the weaknesses in the treatment or the intervention later on. But I very in favor of all neuroscience research, looking at circuitry.
You mean, like deep brain stimulation?
Deep Brain Stimulation (DBS) is even more theoretical than TMS, but it’s basically looking at the same idea of trying to stimulate the brain in an important area. Now vagus nerve stimulation (VNS) is a treatment that’s lost favor rather quickly. This was something that didn’t have the best scientific base behind it, and as I understand it, and that company is not doing very well.
And so models to try to pursue this neurocircuitry thing have not yet really made the mainstream of treatment, but I applaud anyone who is trying to do a better job of helping us understand the roots of depression in the brain. We’re just not there yet.
Do you think we’ll be there at a time in the future when we can go to Rite-Aid and get a depression test?
Well, a lot of people are working on that. When I was young, twenty years ago, the dexamethasone suppression test was supposedly going to be that test. It was trying to look at people’s cortisol levels at different times of the day. People who were depressed would have a different response. But it turns out it wasn’t good enough to be a test for depression
At this point, there is no blood test, and there is no brain scan that really define people. What we have are diagnoses that are reliable, but may not be valid. Now let me explain that for a minute.
If five psychiatrists interview the same person, they’re very likely to come up with the same diagnostic category. Very likely. This is a major depression. Now is that diagnosis valid? That is to say, did God make this condition called major depression with or without psychotic features, with or without melancholia? How do we know the biochemical differences between those two illnesses? The answer is we don’t. What we do now is syndrome recognition based on consistently presented symptoms, that multiple interviewers can come up with the same syndrome.
It’s a little bit like in the 1800s you had Yellow fever or Red fever … what were the fevers caused by? We didn’t know but we could identify that we had a fever. This is a little bit about the way we are with psychiatric illness.
Now I’m not ashamed of that, because if you consider that two-thirds of the human genome have something to do with the central nervous system, you figure it would take us a little longer to break down some of these things. That’s just the status of the condition right now, and we don’t yet know the etiology of these conditions. We do know that they cause a lot of suffering, that treatment tends to work—if you get the right treatment combination—and that a lot of people do really well.
So what we don’t know is the exact biochemical pathway. But I would caution you that even though we do know the exact biochemical pathway that gives us Alzheimer’s disease, we do not have good treatments for Alzheimer’s disease. Scientists have basically worked out all of biochemistry of how Alzheimer’s disease plays out in terms of the different cascade of certain enzymes and phenomena that get you to the senile plaques that you can see on people’s brains.
We don’t have that chemistry worked out for depression and mental illnesses. But even though they have all that worked out on the Alzheimer’s side, there is no outstanding intervention for that disease. The current treatments slow the course of decline, but that’s all you can say about them.