Like most medical complaints, a depressed mood in and of itself represents a symptom, and not a diagnosis. Indeed, depression is a relatively nonspecific complaint, that could reflect anything from the most debilitating psychiatric illness to a normal response to stress or loss (Fig. 3-1). The differential diagnosis for depression among psychiatric disorders alone is broad, requiring a thorough history, examination, and often laboratory tests to discern the underlying etiology (or at least exclude potential confounders). The assessment of mood disorders in the medically ill poses yet several additional challenges, especially since many core, neurovegetative symptoms of depression – such as fatigue, anergia, insomnia, anorexia, weight loss, and pain – often result directly from medical illnesses, themselves. Among patients with severe medical disease, assessment can be confounded by “sickness behavior,” a state of decreased motivation resulting from systemic inflammation, and characterized by malaise, anorexia, insomnia, fatigue, as well as fever.1 Similarly, delirium, especially the hypoactive subtype, can present with prominent mood symptoms, making patients appear dysphoric. Adding to the complexity in assessment, many commonly used treatments, such as steroids or interferon-α, can also lower mood as a side effect. Proper diagnosis remains critical, as the recommended treatment approaches do vary widely, depending on the etiology.
The symptom of depression has several possible causes.
In this chapter, we review approaches for screening and diagnosing depression in the medically ill. We begin in what is likely familiar territory: the common, primary psychiatric diagnoses that present with a low mood, and their implications for medical patients. We then discuss approaches to the clinical interview, available screening tools, the potentially confounding role of delirium in this population, and the assessment of suicidal risk. Finally, we review cultural and ethnic considerations that inform the assessment of depression.
WHEN IS DEPRESSION A DISORDER?
Along with anxiety, a low mood represents a common, typical response to stressors in life. As is the case with bereavement, a certain degree of depression is considered normal, even adaptive, and does not rise to clinical attention. This phenomenon is of special relevance for individuals with medical illness, all of whom face some degree of stress, loss, or burden. Physical suffering, functional limitations, hospitalizations, frequent medical appointments, social isolation, concern about the future, reliance on caregivers, and the financial burdens are just a few examples of illness-related stress. Feeling at least somewhat discouraged is to be expected in these situations, so how do we know when depression requires clinical intervention? The DSM addresses this issue primarily by requiring the presence of “significant distress or impairment in social, occupational, or other important areas of functioning” as diagnostic criteria for a mood disorder.2 That said, even the authors concede that normal grief and illness can coexist and that clinical judgment is ultimately required. For depression ...