Is It Really Alzheimer's Disease?

When Reversible Medical Conditions Look Like Alzheimer's

Woman sitting with father
Getty Images/Peter Zander

If your loved one is experiencing memory problems and other cognitive symptoms, it's important to obtain an accurate diagnosis because the cause may be reversible. Consider the costs -- physically, emotionally, and financially -- of diagnosing someone with Alzheimer's disease when, in fact, the cause could have been treated and the symptoms could have been resolved. Reversible conditions creating cognitive problems include:

Pseudodementia -- When depression creates cognitive symptoms that look like Alzheimer's, it's often referred to as pseudodementia. Depression can result in difficulty thinking clearly, problems concentrating, and trouble making decisions. Pseudodementia often responds well to a combination of antidepressant medication and psychotherapy.

Thyroid problems -- People with thyroid problems can have hypothyroidism (an underactive thyroid gland) or hyperthyroidism (an overactive thyroid gland). Thyroid problems can cause cognitive problems such as forgetfulness and difficulty concentrating. Medications can either replace the function of an underactive thyroid or suppress the function of an overactive thyroid. Some people with thyroid problems see their symptoms improve within a few days or weeks after starting the appropriate medication.

Dehydration -- Dehydration occurs when the body has lost too much fluid, which affects the body's balance of electrolytes (e.g., sodium, potassium). Severe dehydration can cause confusion that looks like Alzheimer's disease. Dehydration is treated by replacing fluids and electrolytes with water or liquids that contain electrolytes. In severe cases, fluids may need to be administered intravenously.

Malnutrition -- Malnutrition occurs when a person isn't getting enough nutrients due to an inadequate diet (not enough food), an unhealthy diet, or digestive problems that make it hard to absorb nutrients into the body. Vitamin B-12 deficiency is one of the most common types of malnutrition. Malnutrition can prevent the brain from functioning properly, often resulting in confusion. Malnutrition is treated by replenishing the body with nutrients either with food or nutrition administered intravenously.

Infections -- Infections can affect the brain's functioning, resulting in confusion, foggy thinking, difficulty concentrating, or forgetfulness. Urinary tract infections are a common cause of cognitive problems among older adults. Infections are treated with antibiotics, and symptoms often subside soon after starting antibiotic treatment.

Medication problems -- A common medication problem among older adults is that a dosage is too high because the older person can't break down and absorb the medication as quickly as a younger person. Other problems include taking or being prescribed the wrong medication altogether or interactions between medications (to check for drug interactions between common prescriptions, see Drugs A to Z). Common medications that cause cognitive problems are sedatives (used for reducing anxiety or improving sleep), hypnotics (used for improving sleep), blood pressure medications, and arthritis medications.

When a medical condition causes a rapid onset of cognitive symptoms, such as changes in consciousness, thinking, and behavior, it's called delirium. In some cases, delirium needs to be treated immediately to prevent permanent brain damage or death.

Uncovering a reversible medical cause requires a full diagnostic workup, similar to the procedures used to diagnose Alzheimer's disease. Several possibilities might need to be explored before an accurate diagnosis is made. Only then can proper treatment be started that focuses on whatever is causing the Alzheimer's-like symptoms.

American Psychiatric Association (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author.

Diagnostic procedures. Alzheimer's Association. April 13, 2007.

Zarit, S. H., & Zarit, J. M. (1998). Mental disorders in older adults: Fundamentals of assessment and treatment. New York: The Guilford Press.

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