Among the mood disturbances, depression is the most frequent cause of emotional suffering in older adults. Depression decreases the quality of life of the elderly, increases functional decline, and, when severe, is associated with a shortened life expectancy. Bipolar disorder, although much less frequent, can be most burdensome to the elderly and a difficult management problem for the clinician. Therefore, the diagnosis and treatment of mood disorders are among the most important and challenging tasks facing the geriatrician and other health-care providers.
During the past few years, a significant effort has been generated to better understand these common and frequently disabling maladies. We have learned much about the causes of late-onset depression. The evidence base for therapy has increased dramatically for both major depression and bipolar disorder. This chapter begins by first exploring current case definitions. Next, both clinical and community-based epidemiological studies are examined so that the reader appreciates the burden of depression across multiple settings. This is followed by extant evidence that informs us of the origins of late-life depression from a biopsychosocial perspective. The chapter concludes with a review of current therapies for depressed older adults. These therapies range from medications and electroconvulsive therapy (ECT) to family interventions.
Although clinicians frequently disagree about exact case definitions of late-life mood disorders, the most cogent subtypes are presented below, subtypes relevant to clinical practice. Naturally, clinicians encounter frequent overlap of subtypes. For example, the acute and usually self-limiting episodes of major depression may be accompanied by chronic and less severe mood disturbances, such as dysthymia. In addition, the symptoms of late-life mood disorders often overlap with other psychiatric and physical disorders. Therefore, these case definitions or subtypes may be more useful for coding and communication than for actual patient care. These do remind the clinician, however, of the variation in symptom presentation and the necessity to tailor treatment strategies to the individual.
Major depression is the “bread and butter” diagnosis for moderate-to-severe, yet self-limited, mood disorders in late life. To be diagnosed with major depression according to the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), the older adult should exhibit most of the time for at least 2 weeks one or both of two core symptoms—depressed mood and/or lack of interest or pleasure in usual activities—along with four or more of the following symptoms: a feeling of worthlessness or inappropriate guilt, a diminished ability to concentrate or make decisions, fatigue, psychomotor agitation or retardation, insomnia or hypersomnia, significant decrease or increase in weight or appetite, and recurrent thoughts of death or suicide ideation. See Table 70-1 for a description of how the symptoms of major depression may vary with older adults compared to younger adults.
Table 70-1 Diagnostic Criteria for Major Depression and Description of How Symptoms May Vary Compared to Those in Younger Adults