Ruling out medical conditions that can cause depression or cognitive impairment is essential in effectively caring for elderly patients. Case examples illustrate how these may present. Diabetes can cause confusion due to either hyper- or hypoglycemia. Congestive heart failure and chronic obstructive lung disease can cause hypoxia and resulting confusion. Sleep apnea can present with amnesia, apathy, and depression. Physiological changes make elderly patients especially susceptible to adverse drug effects, including hyponatremia and anticholinergic symptoms. Depression and cognitive changes have been associated with both hyper- and hypothyroidism, as well as with hyperparathyroidism. Elderly patients are at risk for developing subdural hematomas which can present with cognitive deficits and blunting of mood, and some patients may not have taken notice of the traumatic incident. Vitamin B12 deficiency can present with neurological symptoms including dementia, and cancer may present with fatigue and weight loss, which may be interpreted as depression.
