What is the relationship between common illnesses and depression? And why is the relationship so strong? What can clinicians do now to manage both the medical illness and the depression?

Here to shed light on the bidirectional relationship between the brain and other organs and the common biologic processes that affect all organs is Andrew J. Cutler, MD, who is board-certified in internal medicine and psychiatry. Dr Cutler is on the clinical faculty in the Department of Psychiatry at the University of Florida. He is also CEO and Chief Medical Officer of the Florida Clinical Research Center in Bradenton.

Some key points addressed in this podcast:

• People who have chronic conditions, such as heart disease or diabetes or RA, are at risk for depression. What’s underappreciated is that this is not a reactive depression: the same biologic conditions that cause the primary medical condition can also cause changes in the brain that can trigger the depression. Thus, there is a need to screen for depression in patients with chronic illness. Aggressive management of the underlying medical illness can help prevent or diminish depression.

• Conversely, aggressive management of depression can decrease the risk of a variety of medical illnesses.

• In the context of a 10-minute office visit in a patient with a chronic illness, screening tools to identify the likelihood of depression can be administered in the waiting room.

• Commonly available tools to monitor for depression include measurement CRP: if the CRP level is elevated, it signals that the patient is overproducing cytokines—a marker of inflammation and a risk factor for depression.

• Effective antidepressant therapy can sometimes reduce CRP levels.

• There is a strong association between inflammation and various medical conditions. For example, people who are overweight or obese have elevated markers of inflammation. Abdominal fat causes inflammation, which may explain the relationship between obesity and depression.

• Inflammation can prevent neurogenesis and can be toxic to nerve cells. Thus, unmanaged inflammation can “stun” the brain.

• Readers are referred to a study by Charles Raison, MD, et al, which showed that the TNF antagonist infliximab may improve depressive symptoms in patients with high baseline inflammatory biomarkers.