Depression and medical illness often coincide, presenting a complex treatment challenge, with little research supporting the effectiveness of pharmacotherapy in this situation.
Depression is twice as prevalent among diabetic individuals as in the general population. In patients with neurologic disorders, the depression rate is even higher, and in patients with Cushing's disease or HIV infection, the rate is higher still.
"It's a two-way street," said Dr. Michael Popkin, processor of psychiatry and medicine at the University of Minnesota, Minneapolis. "Major depression brings about a host of physiological changes [involving the] autonomic nervous system, platelet aggregation [and] immune system function that can have an impact on the course and progress ion of Axis III problems."
The adverse effect of depression on cardiovascular disease has been well documented. In diabetes, depression is associated with poor compliance and increased complications, is, he said.
Aggressive treatment is thus doubly important, but such an approach is all too easily under mined by clinical nihilism. "It's important to avoid the snag of thinking that depression is an understandable reaction to illness" that must be endured, said Dr. Thomas Wise, professor and vice chair of psychiatry at Georgetown University, Washington.
Diagnosis may require teasing out vegetative symptoms of depression from those of medical origin. Appropriate treatment may depend on distinguishing among pheromenologically similar entities: major depressive disorder, reactive response to the illness as stressor, mood disorder due to the medical condition, and medication effects, Dr. Popkin said.
For drug-induced depression, the obvious first strategy would be to try to eliminate the off ending agent (such as a [beta]-blocker or corticosteroid) or reduce the dosage. Effective treatment of a medical illness like hypothyroidism or liver disease may ameliorate mood symptoms.
Aspects of the disease that could be making depression worse, such as pain, should be addressed aggressively, Dr. Wise said.
"If I thought the depression represented an adjustment disorder, I might emphasize a psychotherapeutic approach at the outset, moving on to medication if necessary;" Dr. Popkin said.
A history of prior affective disorder argues for the likelihood of a recurrence, perhaps linked to the stress of the illness. In this case, "I'd go back to what contained the depression in the past, Dr. Popkin said.
Whatever the origin of the depression, drug therapy is often necessary. Although the literature suggests that the same medications used to treat depression occurring alone are effective for depression in the medically ill population, few randomized controlled trials have been conducted in those with a medical illness, Dr. Popkin said.
The antidepressant should be chosen with the medical context in mind. On the simplest level, a once-daily formulation offers particular advantages to a patient who is already following a complex regimen, Dr. Wise said.
Don't overlook possible drug-drug interactions, particularly with antidepressants that affect liver enzymes. "You have to be careful not to raise the [effective] dosage of another medication to a toxic level," said Dr. Charles Ford, professor of psychiatry at the University of Alabama, Birmingham.
Among selective serotnin reuptake inhibitors (SSRIs), citalopram (Celexa) and sertraline (Zoloft) probably have the least potential to raise the dosage of another medication, he said.
Antidepressant side effects may be particularly problematic for a patient who is already burdened by illness. But antidepressants may, conversely, be deployed to counter medical symptoms, Dr. Ford said.
Sedation, for example, might be intolerable to a patient fatigued by illness, whereas an activating drug would be helpful. …