Swank Center for Memory Care and Geriatric Consultation, ChristianaCare
About half of individuals affected by Alzheimer’s disease will experience clinically significant depressive symptoms at some point. Depression can occur during early, middle, or later phases of the illness. The timing of depression during Alzheimer's influences its characteristics and also helps to determine the treatment approach that will be most likely to help.
Alzheimer’s disease is now being diagnosed earlier and earlier, thanks to our growing use of biomarkers. Specialized brain imaging can identify a disease hallmark, called amyloid plaques, in living people, even when cognitive impairment is minimal or absent. Alzheimer's interferes with the brain's chemical messengers most associated with mood, even at an early stage of its development. Some researchers have suggested that depression in early Alzheimer's is related to the disease’s primary brain-altering effects.
An early diagnosis can trigger a “reactive depression,” a depressive response to the serious news of disease and impending future cognitive decline. As with other neurological disorders such as Huntington’s disease or stroke, depression in Alzheimer's probably represents a debilitating mixture of reactive and primary influences.
There is a famous look-alike condition called “dementia syndrome of depression.” In this case, a person affected primarily by a depressive disorder experiences mental slowing and forgetfulness that suggests Alzheimer's. In some people, depression later turns out to have been an early sign of oncoming dementia, but many others experience significant cognitive improvement once the depression is treated.
As the damaging effects of Alzheimer's intensify, depression can take on a different quality. Apathy is often prominent when depression emerges during Alzheimer’s middle stage. However, classic depressive symptoms such as agitation, crying, the inability to experience pleasure (anhedonia), loss of appetite, suicidal ideation, and psychotic delusions may also occur. As cognitive decline becomes more severe, an affected person may be unable to remember symptoms of depression or to understand and articulate their meaning. Instead, in the late stages of the disease, disruptive behaviors such as resisting care, expressing delusions, or displaying increased agitation and even self-destructive behavior may indicate depression.
Treatment of depression in a person with Alzheimer's differs in important ways from the treatment provided to individuals with depression who do not have dementia. Insight-oriented or behavioral psychotherapy, which are helpful to depressed older adults with intact cognition or mild cognitive decline, can be useful during the earlier stages of Alzheimer's. However, these approaches are not considered likely to be helpful once the person with Alzheimer's can no longer comprehend and retain information from session to session.
Early on, the therapist’s role may include tasks somewhat unique to treating people with neurodegenerative disorders like Alzheimer's. The therapist may encourage the person to consider long-range plans, including estate planning and advance directives for financial management, residential decisions, treatment, and implementation of end-of-life care wishes. Psychotherapy with a severely impaired person typically involves relieving symptoms with an emphasis on activities. The planning of pleasant events and the use of distraction and redirection are appropriate measures for those with advanced Alzheimer's. Fun and engaging group activities that involve exercise or outings may be more soothing in late Alzheimer's than therapy, with the goal of increasing insight and understanding.
Cognitive enhancers, with their modest benefits for memory and activities of daily living, have not proven particularly beneficial in treating depression. Further, the use of medications designed for the treatment of depression in people with Alzheimer's has been controversial. Despite several well-designed studies that showed antidepressant benefits for Alzheimer's, a similar number of other credible studies fail to differentiate the effects of antidepressants from those of placebo.
A large, recent double-blind randomized controlled trial using sertraline in people with Alzheimer's and depression failed to find significant benefits. Yet, some of the study’s data suggest that antidepressant treatment may be of value in certain cases. In practice, many clinicians will prescribe an antidepressant, but discontinue the medication if it is ineffective or if it causes significant adverse effects.
For some, antidepressants are a useful tool for short-term symptom relief, while others may benefit for a longer time period. Research suggests that some non-cognitive behavioral symptoms of dementia such as agitation can respond to treatment with an anti-depressant that targets serotonin, a brain messenger involved in many biological processes impacted by Alzheimer's.
For a list of currently approved Alzheimer's treatments, please see our fact sheet.
Prescribing medication for someone with Alzheimer's and depression is often complicated by side effects or by the possibility of adverse interactions with one or more other medications a person may take. Anticholinergic medications such as tricyclic antidepressants are best avoided for people with Alzheimer's, as research supports a deficiency in the brain chemical messanger acetylcholine. Combination approaches that pair this kind of antidepressant with another targeting serotonin, such as sertraline or citalopram, might increase gastrointestinal symptoms.
If the treatment is effective and the person's symptoms clear, discontinuation of the antidepressant may be appropriate after a period of months. Periodic re-evaluation of the need for an antidepressant plays an important role in limiting unnecessary medication therapy. However, discontinuing an antidepressant in some cases ushers in a depressive recurrence, so the pros and cons of such a discontinuation are weighed on a case-by-case basis.
Alzheimer's caregivers take on great challenges that can place them at increased risk for depressive disorders. Those who are caring for a loved one with Alzheimer's should take steps to protect their physical and mental health, which are stressed by the demands of caregiving. Support groups may also provide a sense of community and comfort during this time. For more caregiver resources, please visit our Alzheimer's Disease Caregiving page.
James Ellison, MD received his medical degree from UCSF in 1978 and trained in psychiatry at the Massachusetts General Hospital (1979-1982).
Receive Alzheimer's Disease breakthrough news, research updates, and inspiring stories.
Your gift can help lead to treatments and a cure to end Alzheimer’s. Fund the latest, promising research and help provide valuable information to families living with this disease.
