What are common psychiatric diseases in the older population and their treatments?

Common Psychiatric Diseases in the Older Population

Depression and behavioral/psychiatric symptoms associated with dementia are the two most common psychiatric problems in older adults, affecting approximately 22% and 30-40% of nursing home residents respectively, with dementia itself having a median prevalence of 58% in long-term care settings. 1, 2

Most Prevalent Psychiatric Disorders

Dementia and Related Conditions

• Dementia affects approximately 5% of persons aged 71-79 years, 24% of those aged 80-89 years, and 37% of those older than 90 years 1
• Alzheimer disease accounts for 60-80% of all dementia cases, followed by vascular dementia (10-20%), dementia with Lewy bodies (5-10%), and frontotemporal dementia (12-25%) 1
• More than half of cognitively unimpaired individuals who subsequently develop dementia had depression or irritability symptoms prior to cognitive impairment, making the distinction between primary depression and early dementia challenging 1

Depression

• Major depressive disorder has a median prevalence of 10% in long-term care residents, while depressive symptoms affect 29% 2
• New-onset depression in older adults was traditionally considered "pseudodementia," but it is now recognized that mood changes are often early symptoms of Alzheimer's disease or related dementias 1
• Depression in older adults with diabetes is significantly more common than in other older adults, with fewer than 10% receiving antidepressant medications despite high prevalence 1

Anxiety Disorders

• Anxiety disorders occur 2-3 times more frequently in older adults than expected population prevalence 1
• Generalized anxiety disorder is usually preexisting and may be exacerbated by illness, while panic disorder may recur during illness in patients with previous panic symptoms 1

Behavioral and Psychological Symptoms of Dementia (BPSD)

• BPSD affects 78% of individuals with dementia, representing a major clinical challenge 2
• These symptoms include agitation, aggression, hallucinations, and emotional outbursts that are associated with worse health outcomes, physical injury, and increased hospitalization rates 1

Other Psychiatric Disorders

• Schizophrenia and schizoaffective disorder: 89% of older adults with severe mental illness receiving institution-based care are in nursing homes rather than hospitals 1
• Bipolar disorder: Prevalence rates are lower in community-dwelling elderly (up to 0.1%) but may be as high as 10% in care homes and hospital settings 3
• Late-onset bipolar disorder (LOB) tends to have milder manic severity but higher medical and neurological burden compared to early-onset bipolar disorder 3

Treatment Approaches

Depression Treatment

• Pharmacological treatment with SSRIs (such as sertraline) and psychological interventions are effective in reducing depressive symptoms in older adults 1, 4
• Patients who receive therapy for depression should be evaluated for improvement in target symptoms within 6 weeks of initiation 1
• Older adults with depression who present with new-onset or recurrence should be treated or referred within 2 weeks, or sooner if the patient is a danger to themselves 1

Dementia Treatment

• FDA-approved pharmacologic treatments include acetylcholinesterase inhibitors (AChEIs) such as donepezil and memantine 1, 5
• Donepezil is available in 5 mg and 10 mg doses, with common adverse effects including nausea, vomiting, diarrhea, and potential for bradycardia and syncope 5
• Nonpharmacologic interventions include cognitive training, exercise, educational interventions, and multidisciplinary care interventions 1

Anxiety Treatment

• After eliminating medical causes, psychotherapy with or without anxiolytics or antidepressants is recommended for anxiety treatment 1
• Benzodiazepines such as alprazolam have been effective in controlled trials, though caution is warranted given fall risk in elderly patients 1

BPSD Management

• Neuropsychological assessment or dementia subspecialist assessment may be helpful when psychiatric symptoms are difficult to differentiate from primary neurologic etiologies 1
• Specific dementia types with prominent psychiatric features include frontotemporal dementia, Lewy body dementia, prion diseases, and Huntington's disease 1

Critical Assessment Considerations

Cognitive Impairment Screening

• Clinicians should assess older adults for cognitive impairment using standardized screening instruments during initial evaluation and with any significant decline in clinical status 1
• The Mini-Mental State Examination (MMSE) can detect impairment in older adults, with scores below 24 points associated with increased hospitalization risk 1

Complex Presentations

• A majority of individuals older than age 80 with cognitive impairment harbor more than one type of brain pathological change, resulting in mixed etiology dementia 1
• Contributing conditions include obstructive sleep apnea, cognitively impairing medications, and excessive alcohol consumption that can exacerbate symptoms 1

Medication Considerations

• Polypharmacy is common in dementia and can contribute to psychiatric symptoms, with anticholinergics, benzodiazepines, and antipsychotics potentially worsening symptoms 6
• SSRIs and SNRIs used to treat depression may cause or exacerbate insomnia 1
• Among hospitalized older adults with bipolar disorder, anticonvulsant medications are predominantly used as mood stabilizers, with rare use of lithium 7

Important Clinical Pitfalls

• Avoid misinterpreting new-onset depression as purely psychiatric when it may represent early dementia 1
• Do not overlook medical causes of anxiety, including hormone-secreting tumors, medication effects, or withdrawal from alcohol or narcotics 1
• Recognize that unrecognized pain is common in dementia and can manifest as increased behavioral symptoms or apparent psychiatric deterioration 6
• Be aware that sleep disturbances affect 42% of adults over age 65 and are associated with depression, cognitive decline, and increased fall risk 1