Psychiatric and Behavioral Disorders in Older Adults
Depression
Depression is not normal aging and is underrecognized because elders present with somatic complaints, pain, insomnia, and appetite loss rather than sadness. Use the Geriatric Depression Scale. Screen for suicide risk - older adults, particularly older men, have the highest completed suicide rate, and access to firearms is a major modifiable risk. Treat with psychotherapy and SSRIs such as sertraline or escitalopram, starting at half the adult dose. Avoid tricyclics (anticholinergic, orthostatic, cardiac conduction effects). Monitor escitalopram dosing with QT-prolonging drugs and in hepatic impairment. Electroconvulsive therapy is effective and safe for severe, psychotic, or refractory depression.
Anxiety, psychosis, and substance use
Anxiety frequently coexists with depression and with medical illness. Psychosis in older adults usually stems from delirium, dementia, medications (steroids, dopaminergics, anticholinergics), or sensory deprivation; primary late-onset schizophrenia is uncommon. Alcohol use is often hidden and presents as falls, insomnia, or labile mood; complicate withdrawal with benzodiazepine tapers and thiamine.
Insomnia and behavioral symptoms
Cognitive behavioral therapy for insomnia is first-line. Avoid benzodiazepines and Z-drugs, which cause falls, fractures, confusion, and dependence. For dementia-related agitation, begin with the antecedents (pain, constipation, retained urine, overstimulation, unmet needs) and caregiver education before any drug; if medication is needed, use the lowest dose for the shortest time and document a target symptom.
Traps
Misclassifying delirium as psychotic depression; starting an SSRI plus a benzodiazepine rather than treating the cause; ignoring bereavement as a distinct, usually self-limited condition; forgetting hyponatremia and falls from SSRIs.
Rule of thumb
New psychiatric symptoms in an older adult are medical symptoms until proven otherwise: check medications, pain, sleep, thyroid, B12, and substance use.