Antidepressant Side Effects in the Elderly: What Caregivers Should Watch For

Your parent's doctor prescribed an antidepressant three weeks ago, but instead of improving, your parent seems more confused, more tired, and less steady on their feet. Before you assume the depression is getting worse, consider that the medication itself may be the problem.

Older adults metabolize drugs differently than younger patients. Hepatic blood flow and kidney filtration rates decline with age, so medications linger in the system longer and hit the brain harder. A dose that works perfectly for a 45-year-old can produce debilitating side effects in a 75-year-old — and those side effects often look exactly like worsening depression.

SSRIs: A Common Treatment That Still Carries Risk

Selective serotonin reuptake inhibitors like sertraline, citalopram, and escitalopram are commonly prescribed to older adults when medication is appropriate. The choice depends on the person's other conditions, medications, and side-effect risks.

Watch for these after starting treatment or changing the dose:

• Hyponatremia (low sodium) — presents as confusion, headaches, and unsteadiness. This is more common in older adults taking diuretics alongside SSRIs.
• Increased fall risk — SSRIs can cause dizziness and orthostatic hypotension, particularly when standing up from a chair or bed.
• GI distress — nausea and diarrhea in the first week are common and usually resolve, but persistent symptoms may need a dose adjustment.
• Emotional blunting — some older adults on SSRIs report feeling "flat" rather than sad, which family members mistake for improvement when it is actually a side effect worth discussing with the prescriber.

If your parent was started on citalopram, ask the prescribing physician about QTc monitoring. Citalopram carries a dose-dependent risk of cardiac arrhythmia in older adults, and the FDA recommends a maximum dose of 20mg for patients over 60.

Beta-Blockers: The Blood Pressure Drug That Can Tank Mood

Lipophilic beta-blockers — particularly metoprolol and propranolol — cross the blood-brain barrier and depress central adrenergic activity. Your parent may have been taking one for years for high blood pressure or atrial fibrillation without anyone connecting it to their low mood.

Signs a beta-blocker may be contributing to depression:

• Persistent daytime fatigue that does not improve with rest
• Disrupted REM sleep — vivid nightmares or frequent waking
• Low physical energy that the parent attributes to "just getting old"
• Reduced motivation to engage in previously enjoyed activities

Not all beta-blockers carry the same risk. Atenolol is hydrophilic and does not cross into the brain as readily. If your parent's depression coincided with starting or increasing a beta-blocker dose, ask whether switching to a hydrophilic alternative is clinically appropriate.

Corticosteroids: Mood Disruption Starting on Day Five

Prednisone, dexamethasone, and methylprednisolone are commonly prescribed for COPD flares, arthritis, and autoimmune conditions. They can also cause psychiatric side effects in older adults.

Corticosteroids disrupt neurotransmitter pathways in the brain. Short-term courses may produce euphoria or irritability, while long-term systemic administration strongly correlates with clinical depression, insomnia, and cognitive disturbance. Symptoms can appear as early as five days after treatment starts and are dose-dependent.

If your parent is on chronic prednisone for a condition like polymyalgia rheumatica, monitor mood changes with the same discipline you would use for any new psychiatric medication. Document shifts on a weekly tracking log and bring the documentation to the next appointment.

Benzodiazepines: Prescribed for Anxiety, Fueling Depression

Lorazepam (Ativan), alprazolam (Xanax), diazepam (Valium), and temazepam are central nervous system depressants. In older adults, they cause chronic sedation, cognitive slowing, emotional blunting, and memory impairment — symptoms that directly overlap with depression.

The American Geriatrics Society Beers Criteria explicitly recommends avoiding benzodiazepines in adults over 65 because they nearly double the risk of falls and fractures while offering diminishing therapeutic returns.

Yet benzodiazepines remain widely prescribed to older adults for sleep and anxiety. If your parent is taking one, the medication may be contributing to the symptoms you are observing. Abrupt discontinuation is dangerous — benzodiazepine withdrawal requires a supervised taper — but raising the question with the prescriber is essential.

What to Do With This Information

Bring a complete medication list to your parent's next appointment — prescription drugs, over-the-counter products (including diphenhydramine-based sleep aids), and supplements. Ask the physician or pharmacist to review every medication against the AGS Beers Criteria and flag anything that could be contributing to depressive symptoms.

The Spotting Elder Depression toolkit includes a medication audit worksheet that walks you through this process step by step, along with clinical scripting prompts for asking the right questions without alienating the medical team.

One medication change can sometimes do more for an older adult's mood than adding another prescription on top of the pile.