The link between major illness and depression: treating depression aggressively when you have other health problems can improve your quality of life and your medical outcome.
Leaving depression untreated, on the other hand, can have serious consequences. Numerous studies suggest that depression can make illness worse. One investigation, a three-year University of Washington study of 4,154 patients with type 2 diabetes, found that those whose illness was accompanied by minor or major depression had significantly higher mortality rates than those who had diabetes alone.
"It's clear that there is an association between depression and certain illnesses, such as diabetes," says Dan Iosifescu, MD, a staff psychiatrist at Massachusetts General Hospital's Depression Clinical and Research Program and an assistant professor in psychiatry at Harvard Medical School. "But at this point, it is very hard to say what causes what. We know that depressed people have more medical conditions, and that people with medical conditions have higher rates of depression. But we haven't determined if one condition causes the other, or whether a common risk factor causes both the illness and the depression.
"What we do know is that you can and should do something if you're depressed. Most people with illness-associated depression need an aggressive treatment combination of medication and therapy."
CAN THE LINK BE EXPLAINED?
Feelings of depression that last more than two weeks may indicate a mood disorder that requires professional treatment. No one is sure why there are higher rates of depression associated with certain diseases, but scientists have proposed a number of theories:
Behavioral factors: Behavioral explanations of the depression/illness link suggest the two conditions can influence one another. Research has shown that people who are depressed are less likely to follow diets, exercise, take their medications, and change unhealthy behaviors such as smoking. Their behavior may lead to poorer medical outcomes, and account for the depression/illness association.
On the other hand, perhaps people who are physically sick become depressed because of the psychological and physical impact of their disease on daily life. They may be coping with such factors as pain, weakness, disability, a discouraging prognosis, isolation, and restrictions on their activities.
But behavioral explanations fail to explain why only some people with illnesses suffer depression--or some people with depression get sick--while the majority of patients do not. This seems to indicate that other factors influence the depression/illness association. Medications: Many medications may have side effects that include depression, which is one possible reason why people with certain diseases tend to have higher rates of depression.
Medications associated with depression include: interferon (up to 70 percent of people treated with this drug develop symptoms of depression), medications for high blood pressure, some heart medications, and steroids, to name a few. Drug abuse may also contribute to depression.
Disease-specific physiological factors: Certain diseases--such as Parkinson's disease and stroke--involve physiological changes that can cause depression. Half of all cardiac patients develop depression following surgery, possibly as the result of microscopic vascular damage in the brain during the procedure.
Cortisol and stress mechanisms: With repeated or prolonged stress, the body can lose the ability to respond to stress, opening the way to health problems. It may also lose the ability to return to normal after a crisis, leaving chronic high levels of the stress hormone cortisol--associated with the fight-or-flight response--to wreak havoc on both the body and brain. A substantial body of research has demonstrated the link between chronic stress and depression. Other studies suggest chronic stress can also impair the immune system and have profoundly negative effects on all body systems, causing medical illnesses to worsen. Chronic stress, then, offers a plausible explanation for the association between depression and illness.
Inflammatory processes: A number of medical conditions are associated with chronic abnormal inflammatory processes. A byproduct of inflammation found in the blood called C-reactive protein is a predictor of many diseases including cardiovascular disease, diabetes, and arthritis. There are also high levels of inflammatory factors in depression. Antidepressants lower these inflammatory factors. It's possible the link between depression and certain illnesses may be explained by the presence of non-specific inflammation or factors associated with inflammation.
Personal factors: Your approach to life, your resilience when things go wrong, your genetic vulnerability, your experiences--these personal variables may also influence the depression/illness link. A person who is predisposed to depression may become depressed as a result of a stressor, whereas another person exposed to the same stressor might not become depressed.
If you are experiencing depression as well as an ongoing medical condition, ask your doctor what treatment options are available. Chances are that appropriate treatment can improve both your mental and your physical status.
WHAT YOU CAN DO
Most of us have brief bouts of the blues from time to time, especially during times of stress. But you should consider seeking professional help for your depression if it lasts more than two weeks and is accompanied by any of these symptoms:
* Sleep and appetite disturbances
* Persistent feelings of sadness, emptiness, hopelessness, guilt or worthlessness
* Loss of interest in or pleasure from activities that were once enjoyed, including sex
* Decreased energy
* Difficulty concentrating, remembering or making decisions
* Thoughts of death or suicide
* Restlessness or irritability
WEIGHT CAN INTERFERE WITH ANTIDEPRESSANT
Being overweight may make you less likely to respond to antidepressant treatment with a selective serotonin reuptake inhibitor (SSRI), according to investigators at the Massachusetts General Hospital's Depression Clinical and Research Program. They found that, up to a point, the heavier you are relative to your height, the greater your body's resistance is to SSRI treatment.
In the first study to focus on the relationship between body weight and response to antidepressant medications, researchers at Massachusetts General Hospital enrolled 369 depressed males and females in an 8-week trial in which they were treated with 20 mg doses of fluoxetine (Prozac). All subjects were given the same dose of fluoxetine.
At the outset of the study the subjects underwent thorough physical examinations in which their weight and height were measured and their body mass index (BMI) was calculated. They were rated for depression at baseline and during weekly visits using structured questionnaires in which they were asked to rate their feelings such as depression, anxiety, anger, and hopelessness.
At the study's end, researchers assessed the relationship between subjects' BMI and their responses to SSRI treatment. The researchers found that the greater the relative body weight of a patient, the greater the likelihood that the medication would not be effective. "Patients with a greater BMI at baseline were less likely to respond to treatment regardless of the severity of depression at baseline," the authors noted.
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|Publication:||Mind, Mood & Memory|
|Article Type:||Disease/Disorder overview|
|Date:||Oct 1, 2006|
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