TCPR: Psychiatrists often have patients who come in bearing long lists of medications for various comorbid conditions. Is there any evidence that we should evaluate and treat such patients differently than patients without medical illnesses?
Dr. Katon: Researchers have been studying the interaction between depression and chronic medical illness for a couple of decades. In 2003, I published an article in Biological Psychiatry that hypothesized that there is a bidirectional interaction between depression and chronic medical illnesses, and I think since then there is extensive evidence to support this theory (Katon WJ, Biol Psychiatry 2003;54(3):216–226). A person with a mental illness plus a chronic medical illness is, on average, twice as functionally impaired as a person with just the medical illness. For instance, take people with depression and diabetes compared to those with diabetes alone—not only do such patients perceive themselves as much more functionally impaired, but they are also more likely to develop actual complications of their illnesses.
TCPR: What else has that research shown?
Dr. Katon: Data shows that having either depression early in life or other childhood adversities, like physical or sexual abuse, are each independently associated with premature development of chronic medical illnesses (Von Korff M, Scott K, Gurejo O, eds. Global Perspectives on MentalPhysical Comorbidity from the WHO World Health Surveys, Cambridge, UK: Cambridge University Press; 2009).
TCPR: And why do you think this is?
Dr. Katon: It probably occurs because of two or three things. One is that depression, particularly developed earlier in life, is associated with health risk behaviors like smoking, poor diet, obesity, and sedentary lifestyle. A second reason is that depression is associated with biological factors like higher cortisol levels, which may lead to obesity, other abnormalities in the HPA [hypothalamic-pituitary-adrenal] axis and autonomic nervous system, and also an increase in pro-inflammatory factors that may raise the risk of cardiovascular and cerebrovascular diseases. Finally, we have seen that having depression and a chronic medical illness makes it harder to cope with medical symptoms like pain (Bair MJ et al, Arch Intern Med 2003;163(20):2433–2445).
TCPR: How does all this affect the questions we ask, the kind of therapy we offer, or the recommendations we give these patients?
Dr. Katon: Well, one way that psychiatric training is not adequate is that once we have successfully treated the depression, we psychiatrists tend to pat ourselves on the back and feel like we have done our job. But we need to be aware that our patients with chronic mental disorders are dying anywhere from five to 25 years earlier than the general population. The evidence shows that schizophrenics die about 20 to 25 years earlier, patients with bipolar disorder die 10 to 20 years earlier, and those with depression die five to 10 years earlier (Colton CW et al, Prev Chronic Dis 2006;3:11–42). They are dying prematurely from illnesses like diabetes, heart disease, cancer, and COPD.
TCPR: Those are pretty dramatic figures. Are there any known interventions to help curb this?
Dr. Katon: Well, some of the very medicines we use, such as atypical antipsychotics, mood stabilizers, and some antidepressants actually cause obesity, and may worsen or provoke the early development of diabetes.
TCPR: With this in mind, what are some medication recommendations for patients with chronic medical illnesses?
Dr. Katon: We know certain antidepressants like mirtazapine (Remeron) and tricyclics are highly associated with weight gain. Of the SSRIs, probably paroxetine (Paxil) is the most likely to cause weight gain (Bostwick JM, Mayo Clin Proc 2010;85(6):538–550). There are some trials of long-term maintenance treatment of type 2 diabetics treated with bupropion (Wellbutrin) that actually show weight loss (Lustman P et al, Diabetes Care 2007;30(3):459–466). In terms of mood stabilizers, lithium, carbamazepine (Tegretol), and valproic acid (Depakote) all can induce weight gain. Lamotrigine (Lamictal) is not associated with weight gain, so that may be the best choice in people we are worried about developing diabetes if they are obese. Among the atypicals, ziprasidone (Geodon) and aripiprazole (Abilify) have the lowest risk for obesity. The high risk drugs are clozapine (Clozaril) and olanzapine (Zyprexa), and the moderate risk drugs are quetiapine (Seroquel) and risperidone (Risperdal).
TCPR: What are some behavioral strategies you recommend for these patients?
Dr. Katon: Frequently with my depressed patients, after their depression gets better, I find out that they are doing something like drinking a six-pack of cola a day. If you have a patient who is a couch potato, who smokes and is overweight, and you successfully treat his or her depression, he or she may still have maladaptive health habits. Treating depression alone will not lead to changes in health habits for most people. It will in some, because when their depression goes away they will start to exercise and live healthier lifestyles. But in most people, once their depression is better, we should be thinking about counseling them about habits that put their health at risk, such as smoking and poor diet.
TCPR: What kinds of medical procedures should we be doing with our patients who have medical illnesses?
Dr. Katon: You can estimate BMIs (body mass index) to see if they are obese, and you can check their blood pressures. There are now very inexpensive automatic blood pressure cuffs that don’t even require you to use a stethoscope. Patients can even use these at home to monitor their own blood pressure.
TCPR: So should we re-educate ourselves about how to treat hypertension?
Dr. Katon: Most psychiatrists are not going to treat hypertension ourselves, but we certainly can check blood pressures. You can also ask basic questions: Do you smoke? Are you motivated to quit? What is your diet like? How much weight do you need to lose? Then, if you have a connection to an internist you could say to your patient, “Ms. Jones, I am concerned about your blood pressure being too high. Do you have a primary care doctor? If you do not, I have several recommendations, and I would really like you to see one because this puts you at risk of a heart attack.” So we can do the screening and education without doing the treatment.
TCPR: And working closely with the internist would seem especially important with these patients.
Dr. Katon: Yes, because we often find out about the poor control and the lack of adherence before the primary care doctors do, and we need to be able to work with them to help patients get better and stay better. We have done some studies where we have treated only depression among people with diabetes, and we have compared the results with other trials where we help the patients not only with depression, but with control of their medical conditions, too. We have seen twice the rates of improvement of depression when we have helped patients with all their medical concerns (Katon W et al, Contemp Clin Trials 2010;31(4):312–322).
TCPR: That’s an interesting finding. Addressing the medical issues more aggressively improves our treatment of depression. Why is that?
Dr. Katon: That is because patients are often worried and feeling guilty about the fact that they are not doing better with their medical control. And because these are genetic diseases, often they have watched their mom go blind from diabetes or watched their dad die early from a heart attack. So somewhere in the back of their minds they are always worrying, “Gee, I am not taking care of myself,” and that worrying can fester and worsen their depressive states. The benefit of psychiatrists helping with health habits, paying attention to disease control, and working closely with primary care doctors, is that we can do a much better job treating people’s depression by paying attention to the patient’s whole health. To put it more bluntly: If we treat someone’s depression and he or she dies five years later of a heart attack at age 45, we really haven’t done our job.
TCPR: Thank you, Dr. Katon.