Brought to you by the Depression Is Real Coalition, The Down & Up Show is dedicated to the reality of depression. Each week our hosts will talk with some of the world's top experts on depression, as well as people who have been impacted by this illness. The reality of depression is that it is a debilitating and potentially deadly medical condition that affects more than 15 million Americans every year. The other reality of depression is that there is hope.

Down & Up Show #48: Coronary Heart Disease and Depression

DR. REEF KARIM:
Welcome to The Down And Up Show, on depressionisreal.org. I'm your host, Dr. Reef Karim; psychiatrist, addiction specialist, and relationship therapist. Our guest today is Dr. Karina Davidson, an associate professor of medicine at Columbia University College of Physicians and Surgeons.

Dr. Davidson's research focuses on the roles of psychosocial factors in patients with cardiovascular disease. She's recently developed an interest in reduction of depression in patients, and subsequent improvement in their cardiovascular health. Thank you for joining us today, Dr. Davidson.

DR. KARINA DAVIDSON:
Thank you. I'm glad to be here.

DR. REEF KARIM:
Good. So, let's start out here. As far as depression goes, there's been strong evidence that depression can lead to higher death rates from coronary artery disease, and there's been -- but there's really been less research on how the exact symptoms of depression affect people with -- with potential heart failure, cardiovascular disease.

So tell us, just straight up, how does depression affect a person's [inaud.] their coronary health?

DR. KARINA DAVIDSON:
We are chasing right now the exact behavioral, or biological, or other pathway that might lead from depression to exacerbated cardiovascular disease. There are a number of exciting mechanisms that we're chasing, so for example, we know that patients who have omega-3 fatty acid deficits are both at risk for depression, as well as for accelerated heart disease.

So that may be one mechanism by which depression is conferring its risk. We also know, and this has been a fairly recent set of studies, that depressed patients don't take their medications, their cardiovascular medications.

And so even from the day they leave the hospital after a heart attack, they often have trouble, either because of memory or motivation, getting to the pharmacy, receiving their pills, and taking them as scheduled. So that's another behavioral mechanism that we're -- we're chasing in order to understand why it is that these depressed patients are at increased risk.

DR. REEF KARIM:
Yeah, because we all know that part of depression is decreased motivation, you know, the lethargy, the fatigue. So you can get to the point where even though you have serious medications that need to be taken every day for your heart, you may just not feel motivated or really in the mood to take them.

DR. KARINA DAVIDSON:
And one of the interesting findings we're having is depressed patients not recalling that they were told that these were very important medications for them to take. So memory problems that come along with depression may also be working in the wrong direction.

DR. REEF KARIM:
Yeah. Is there a difference between how depression affects the heart and the coronary artery?

DR. KARINA DAVIDSON:
We don't really know the answer to that yet. In otherwise normal, healthy patients, they are more prone, independent of their cardiovascular risk factors, to early heart attacks. Some have argued that it's probably an atherosclerotic progression that's causing that excess risk, but we -- some recent data has suggested that's not true.

Depressed patients' blood is actually more hypercoagulable, and so we think maybe the heart attacks are being... Increased, because the blood is more likely to clot, or to have upregulated platelet aggregation.

One of the interesting findings we've had in patients who already have established cardiovascular disease, is where -- where the diseased coronary arteries are, if we put them under a standardized stress test, we actually see that those arteries constrict in those segments that are diseased.

Whereas in patients who don't have depression, or some other kind of large, negative emotion, that diseased coronary artery actually dilates.

DR. REEF KARIM:
Can you speak a little more about the platelet aggregation?

DR. KARINA DAVIDSON:
One of the interesting things that happens when you work between psychiatry and medicine is, you go to one lecture in psychiatry where people are talking about serotonin, as one of the... You know, very major disregulations that happen in depressed patients.

And then you come back to medicine, where the lab scientists comment that there's this serotonin on the platelet of blood, but that nobody has studied it very much. So one of the things that our group did, as well as with researchers at Mt. Sinai, is we looked at platelets I the blood, and whether depressed patients more easily could clot their blood because of that serotonin receptor on the platelet.

And indeed, we found that's what was going on.

DR. REEF KARIM:
But that would be a decreased amount of serotonin receptor uptake, right?

DR. KARINA DAVIDSON:
Because there's decreased bioavailable serotonin, there are increased receptors, and more dense receptors on the actual surface of the platelet. And so, as soon as they get triggered by a little serotonin, they actually clot more quickly.

DR. REEF KARIM:
Okay. Does the degree... I mean, let's talk severity. Does the degree of the depressive symptoms, or the degree of the cluster of depressive symptoms, affect the degree of their impact in regards to the cardiovascular system?

DR. KARINA DAVIDSON:
It does seem to. We have what we call a dose-response gradient. So the more severe the depressive symptoms, the earlier the heart attack, the -- you know, the worse the prognosis for the patient who already has heart disease.

And conversely, the milder the depressive symptoms, although they are still at elevated risk, it's at less risk.

DR. REEF KARIM:
So it would follow, then, that treating depression, especially early on, can reduce cardiac events.

DR. KARINA DAVIDSON:
It would seem to follow, but one of the lessons we've learned in epidemiology is that observational studies don't necessarily mean causality. And we have had now two or three major depression trials with patients with cardiovascular disease, and not yet shown changes in outcomes on the cardiovascular disease side.

We clearly are able to treat depression, and it appears that we can improve quality of life for these patients, but we haven't yet found the type of treatment that we should be offering that will offset this cardiovascular risk.

Some of the interesting new trials are starting to look at things like exercise as an intervention for depression, or omega-3 fatty acid supplementation, or improving the baroreflex, all is ways of improving depression, and perhaps also altering that cardiovascular risk.

DR. REEF KARIM:
Do you think that's specific to the cardiovascular system? I mean, it -- just in general, physicians are told if somebody's got diabetes and they're depressed, if they have coronary artery disease and they're depressed.

If they have any kind of chronic medical condition and they're depressed, the chances of further compromise in regard to their health status is definitively worsened if they're depressed.

DR. KARINA DAVIDSON:
Absolutely.

DR. REEF KARIM:
But if they're treated, any kind of health or clinical condition could improve, because you're treating the depression.

DR. KARINA DAVIDSON:
That's what we -- we're -- it's a fairly new field, and the fact that depression worsens the medical prognosis for so many medical diseases is now fairly well established, but whether treating depression slows down that medical progression is not yet known.

It's not yet known for diabetes, it's not yet known for heart failure, it's not yet known for arrhythmias, and it's not yet known for cardiovascular disease. But we have a number of exciting trials that are asking exactly that question, out in the field, right now.

DR. REEF KARIM:
Okay. Could you talk for a little bit about the findings of your study, I believe it was entitled "Psychological theories of depression: Potential application for the prevention of acute coronary syndrome recurrence." That was published in Psychosomatic Medicine in 2004, right?

DR. KARINA DAVIDSON:
Yes.

DR. REEF KARIM:
Tell us a little bit about your findings in that.

DR. KARINA DAVIDSON:
Sure. A lot of the treatments that we have developed thus far for depressed patients are for what I would call treatment-seeking depressed patients. Patients whose symptoms are bothering them, and they wish to find some help, you know, for that distress.

Many of the patients that we see with diabetes, with heart failure, with established coronary artery disease, have depressive symptoms, or maybe even meet the criteria for a diagnosis of depression, but they don't necessarily see that as a problem that they wish to have treated.

And so one of the things we examined in a sample of about 457 patients with cardiovascular disease, is we tried to find out what psychological vulnerabilities to depression they had. So as you know, some people's depression develops because they've had a lot of interpersonal role changes, or losses in their life.

For other people, depression develops because they've got cognitive distortions or errors. And yet other people develop depression because they've lost a lot of behavioral reinforcements in their life. Things that they enjoy doing. Taking a walk, spending time with a -- a friend or a relative, and those things have changed recently in their life.

So we were trying to establish if the things that cause depression, or that we think cause depression in a healthy population are the same things that exist or we can find in patients with cardiovascular disease. What we found was that they do report changes in their relationships, or losses of pleasurable activities in their life.

But that didn't seem to predict the persistence of their depressive symptoms. Things like their inflammatory level at the time of their hospitalization did a better job of predicting that.

DR. REEF KARIM:
I saw something really, really interesting that -- you were recently quoted in a USA Today article discussing a study that was presented at the American Psychosomatic Society annual meeting. And in the study, you found that C-reactive protein that's linked to inflammation...

Depressed people have more of it, and it may explain why depressives always have stiffer heart tissue. Could you kind of expand on that a little bit?

DR. KARINA DAVIDSON:
Sure. I just want to clarify, that's not actually my study. I was commenting on someone else's study that was reported at American Psychosomatic Society. What those authors found was that depressive symptoms were highly correlated with inflammatory markers from the blood in patients with heart failure.

And one of the models of depression is called the cytokine or inflammation-induced model of depression. When we take animals and notice that they have high levels of inflammation, they often show what look like depressive symptoms.

They're lethargic, they seem to exhibit learned helplessness, they can't be bothered to get up and go get their food, and the same kind of thing occurs in human beings. If they have enough inflammation in their body, they often report feeling depressed.

And so one of the hypotheses about what may be going on in patients with cardiovascular disease or heart failure is that the inflammation is causing both the heart disease as well as the depressive symptoms. In that case, obviously, we wanna figure out how to therapeutically target the inflammatory markers, and then the depression may resolve.

DR. REEF KARIM:
So what are your thoughts on the findings? How did this... How does this change possible diagnosis and treatment?

DR. KARINA DAVIDSON:
It means we have to start searching for different types of depression in patients with medical problems. So it may mean looking at a patient who's got heart disease and depression, and finding out what their inflammation level is, and then treating that.

So it could send us in some quite different directions about ways to in fact improve patients' quality of life, as well as their heart disease.

DR. REEF KARIM:
And are their other relationships between one's mental health and one's heart's health, so to speak? I mean, could you just describe them?

DR. KARINA DAVIDSON:
Sure. Anxiety, particularly phobic anxiety, has been found quite recently in four or five large studies to predict sudden cardiac death. And those are in apparently healthy people. So there seems to be interest and possible important findings that certain phobias may actually be leading to ventricular arrhythmias that eventually, if left untreated, may cause sudden cardiac death.

That's different than what you see with depression.

DR. REEF KARIM:
So, when -- I remember this in medical school, when -- when patients would come to the emergency room, and they would complain of anxiety related to phobias, or related to just kind of some generalized anxiety or fear of driving or whatever else, we would come in and we'd do an EKG, we'd do some type of cardiac study.

And usually it would be negative, but what you're saying is it actually is a predictor of some type of cardiac compromise?

DR. KARINA DAVIDSON:
In three or four recently published studies, a very large sample. So probably some of us wanna see, you know, in [unint.] or a very large population-based study show it. But I think there's a signal in the data that... And I'm gonna say it's possible two ways.

It could be people who experience high levels of flooding of anxiety, may eventually, through a sympathetic nervous system overactivation, start disregulating their heart across time, that then leads to the problem.

But the interesting flip side of that is, it is possible that people who are starting to experience heart rhythm problems, first feel that as anxiety. So both directions are possible in this finding.

DR. REEF KARIM:
Is there a specific author, or a specific journal that our listeners could look for about those articles?

DR. KARINA DAVIDSON:
Laura Kubzansky from Harvard has published the majority of the studies in this area. Her last name is K-U-B as in boy Z-A-N-S-K-Y.

DR. REEF KARIM:
Okay. Let's -- do you have any closing thoughts you'd like to add on the subject?

DR. KARINA DAVIDSON:
I think right now, for the family member or the caregiver of someone who's got depression or anxiety and a medical diagnosis, they may listen to the podcast and wonder what can they be doing for their loved one. We know that taking medication, getting to cardiac rehab, seeing -- you know, the physician for the follow-up visit, is critically important for insuring that a patient survives, and survives well...

The heart attack, or the cardiovascular event that they experienced. And so I think at this point, what we can offer by way of treatment is, make sure that anything that needs to be done for the cardiovascular disease gets done, and people who have depressive symptoms have trouble taking their meds, getting to the cardiologist, exercising regularly.

All of those become even more important to help your loved one do if you see that they've got symptoms of depression or anxiety.

DR. REEF KARIM:
Okay, great. I mean, this is a great subject. I mean, thank you for speaking with us today, Dr. Davidson.

DR. KARINA DAVIDSON:
Oh, it's been -- it's been fun.

DR. REEF KARIM:
Okay. Join us next week for another segment of The Down And Up Show, on depressionisreal.org. I'm Dr. Reef Karim.