Psychopharmacology for the Elderly: Focus on Depression, Psychosis, and Bipolar Disorder

Article excerpt

Abstract

Late-life depression is a common mood disorder, but is underrecognized and undertreated. Criteria for the diagnosis of major depression stipulate that in addition to having specific symptoms over time, patients must experience significant reductions in their ability to function daily. Patients with latelife depression may have presenting symptoms that diverge from the established diagnostic criteria, which may be a reason why late-life depression is under-recognized. Symptomatic complications of late-life depression include anxiety, psychosis, mania, substance abuse, and suicidal thinking. Although the elderly patient who lives independently has a lower relative risk for depression, patients with increasing numbers of comorbidities are at greater risk for developing it, and such co-occurring illnesses can also adversely affect their outcomes. The pharmacist who commits to the care of late-life depression can saeenfor unidentified depression and advocate for the routine measurement of depression symptom severity. This can be accomplished by the use of validated rating scales such as the Patient Health Questionnaire or the Geriatric Depression Scale. Antidepressants enhance the activity of serotonin, norepinephrine, and dopamine, and are effective treatments for late-life depression. Issues key to their selection and use include understanding known physiologic changes affecting antidepressant pharmacokinetics, ensuring that patients receive an adequate treatment trial, targeting remission as the treatment goal, knowing which antidepressants have clinically important CYP450 enzyme inhibition, evaluating patients for drug-drug interaction risks, and being aware of common and serious adverse antidepressant effects.

Depression is not a natural part of the aging process. Late-life depression, however, is a common psychiatric illness that has significant adverse effects on health status and quality of life. Depending on the population studied, depression in the elderly may occur in up to 50% of patients.18

Generally speaking, community-dwelling elderly have relatively low rates of depression, and elderly patients residing in hospitals or long-term-care facilities or who have co-occurring medical illnesses have higher rates of depression.9

Depressive symptoms in the elderly can range in number and severity, and may represent one of several conditions including bereavement, adjustment disorder with depressed mood, dysthymia (subsyndromal or minor depression), or major depression. Late-life depression has been reported as particularly common in women and in patients with chronic insomnia, chronic medical disorders, social isolation, or declining function, or in those who are experiencing stressful life events.10

For a diagnosis of major depression to be made, patients must have at least five of the nine symptoms included in the Diagnoste and Staüstical Manual of Mental Disorders (DSM)-IV-TR.11 Symptoms must be consistently present for a minimum of two weeks; one of the symptoms must be either depressed mood or anhedonia (loss of interest); and the patient's function must be impaired. The remaining symptoms of major depression include changes in appetite/ weight (most commonly loss of appetite and decreased weight); changes in sleep (most commonly insomnia); decreased levels of physical/mental energy (anergia; psychomotor retardation); feelings of guilt; difficulty making decisions; and suicidal thinking.11

Although late-life depression can present identically to the way major depression might present in young adult patients, aging patients who have late-life depression may also present with symptoms that are not included in the DSM-IV-TR criteria. Alternative types of depressive symptoms have been described that may be part of late-life depression.12

Patients with late-life depression may not report depressed mood or sadness. They may, however, experience irritability, agitation, somatization, cognitive impairment, apathy, paranoia, and/or poor self care. …