8 Causes of Memory Loss That AREN'T Alzheimer's

Worried About Dementia? There May Be Other Explanations
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It's hard not to think of Alzheimer's disease when memory loss or a memory lapse darkens your day. After all, Alzheimer's and other forms of dementia are constantly in the headlines -- and of the more than five million affected Americans, 200,000 are under age 65. But many other situations can also produce this worrisome symptom.

Memory loss is just one Alzheimer's warning sign. Others, for example, include personality changes and problems managing money.

Your safest bet: "If you're concerned about memory issues, see a specialist," says psychiatrist Gary Small, director of the UCLA Center on Aging and author of several books about memory and cognition, including The Naked Lady Who Stood on Her Head. An evaluation will examine the type of memory loss, its timing, environmental factors (such as injuries or drug use), and other symptoms. (See also Worried About Your Memory? 5 Signs It's Serious.)

The eight following conditions are among the non-Alzheimer's causes of memory loss to consider:

Memory Loss Cause #1: Chronic Stress

Why it happens: When the body goes on hyperalert to face a crisis, a series of biochemical changes takes place that fuels the fight-or-flight response system. The chemical cortisol increases in the brain, for example, to mobilize energy and alertness. That's great when a saber-toothed tiger is chasing you. But when tension and anxiety become chronic, as with work or family problems, the system is overloaded with substances that are intended for emergency use only.

Result: The brain actually loses cells and has trouble forming new neurons. This creates problems with cognitive thinking, especially with regard to retaining new information.

What else to look for:

  • Is your sleep disrupted, or are you getting less of it? Sleep deprivation compounds the effects of stress on the brain, because memories are sorted and organized during normal sleep.

  • Are you multitasking your way through a stressful period? Straining the attention system drains memory, too.

Memory Loss Cause #2: Depression

Why it happens: Depression is usually linked to low levels of serotonin, a neurotransmitter connected to the arousal system. Concentration and focus are affected, impairing the ability to properly store new memories. It doesn't help that some depressed individuals dwell on sad events of the past, which can contribute to a lack of attention to the present, which in turn makes it harder to store short-term memories.

Three groups especially vulnerable to depression: older adults, caregivers, and people with dementia. When depression symptoms are treated, memory problems mistaken for dementia often disappear. In people with dementia, symptoms often improve with treatment (they may even go away completely for those with mild-stage dementia).

What else to look for:

  • Are other common signs of depression present? These include a sense of hopelessness, loss of interest or pleasure in formerly enjoyed activities, and changes in appetite or sleep.

  • Can you drive or pay bills? Someone with depression may not feel like doing such tasks, but they can, says psychiatrist Anton Porsteinsson, director of the Memory Disorders Clinic at the University of Rochester. Someone with Alzheimer's can't.

Memory Loss Cause #3: Medications

Why it happens: Drugs affect the entire system, and some interfere with the ability of brain cells to communicate. Sometimes this effect is produced by dangerous interactions between two different drugs -- a common problem for older adults, who often have multiple prescriptions. The average number of prescriptions filled per person of all ages, per year in the U.S. is 12.6 (refills and new), according to a recent Kaiser Family Foundation study.

What else to look for:

  • Have you started a new prescription recently? Be sure all your doctors know about all your medications. Don't be shy about reporting worrisome symptoms back to the prescribing physician.

  • Has there been a change in dosage? What seems like a small adjustment can have big effects.

  • Are you taking one of the drugs that cause memory loss? These include statins for high cholesterol, sedatives, antianxiety drugs, and medications for incontinence.

Memory Loss Cause #4: Malfunctioning Thyroid

Why it happens: In hypothyroidism, the body lacks sufficient thyroid hormone, which regulates metabolism. The entire body, including the brain, is affected when metabolism runs too slowly. Cognitive problems are often an early warning sign of thyroid issues. Researchers are also investigating a possible connection, among women, between Alzheimer's and too high (hyperthyroidism) or too low (hypothyroidism) amounts of the thyroid hormone thyrotropin. (The association hasn't been seen in men.)

What else to look for:

  • Are you experiencing the other symptoms of hypothyroidism? These include fatigue, lethargy, weight gain, dry skin and hair, a loss of libido, irregular menstrual cycle, sensitivity to cold, and muscle cramps. Memory problems tend to happen in tandem with several of these other symptoms, although it's a common initial complaint.

Memory Loss Cause #5: Pregnancy or Menopause

Why it happens: Changing estrogen levels at key points in a woman's reproductive life can affect other brain chemicals estrogen interacts with. Hence, the so-called "fuzzy brain" of pregnancy and the "brain drain" of perimenopause. A 2010 study at the University of Bradford in England found that maternal memory problems are worst from the second trimester through three months postpartum, though not all women are affected.

What's more, these life passages are also times when women tend to be distracted by other intense symptoms (from excitement and nausea in pregnancy to menopausal hot flashes and the multitasking of being a sandwich-generation adult). Distraction adds to forgetfulness because information is not attended to, and therefore never stored.

What else to look for:

  • Are you feeling blue? Researchers believe that depression coinciding with pregnancy or menopause may also have a role in memory problems.

Memory Loss Cause #6: Excessive Drinking

Why it happens: Heavy drinking doesn't just damage the liver and kidneys. Imaging studies have shown proof of brain impairment, too. Shrinkage is worst in the frontal lobe, which governs higher intellectual functions, although other structures are also affected -- including those involved in memory.

Long-term excessive drinking can cause a condition called Korsakoff syndrome, a form of alcohol-induced dementia.

What else to look for:

  • Do you have other signs of alcoholism? These include a history of falls, excessive sleep, drinking alone to cope with difficult emotions, tardiness at work (due to hangovers), and morning drinking.

  • How old are you? The ability to metabolize alcohol declines with age. So two or three beers for a 70-year-old have the same effect as four or five beers did at age 50.

  • Are you drinking and taking prescription medications? Certain drug and alcohol combos can be toxic to the brain, even at relatively low levels of drinking.

Memory Loss Cause #7: Concussion/Head Injury

Why it happens: It's little surprise that, although the brain is protected by a thick skull, brain tissue is vulnerable to trauma. Traumatic brain injury (TMI) can be caused by the brain tissue slamming into the skull itself during a fall or sharp blow, or by an object piercing the skull -- a more obvious explanation for memory loss. The force of impact can cause direct damage or bleeding that causes more widespread problems.

What else to look for:

  • Have the cognitive problems come on suddenly? Alzheimer's disease develops slowly, but memory loss from head trauma can trace to the single incident.

  • Are there other signs of brain injury? These include numbness, excessive drowsiness, severe headache, weakness in arms or limbs, dizziness, dilated pupils, and slurred speech.

  • Do you participate in contact sports? Sometimes athletes suffer concussions in knocks and falls they consider mundane.

  • Has there been a recent car, bicycle, or motorcycle accident? These are among the most common situations for head injuries, especially if the person wasn't wearing a seatbelt (car) or helmet (cycle).

Memory Loss Cause #8: Normal Aging

Why it happens: Memory lapses aren't always a sign that something's wrong. Sometimes they're normal. After all, the brain starts its gradual decline as early as during one's late 20s and early 30s. By the late 40s and early 50s, most people get that "now why did I come into this room?" feeling and have occasional trouble remembering names of new acquaintances or items on shopping lists.

Dementia, such as Alzheimer's, isn't a normal part of aging. But occasional forgetfulness does tend to increase as we get older.

What else to look for:

  • How old are you? The risk of Alzheimer's increases with age. The likelihood of developing it doubles every five years after age 65, according to the Alzheimer's Association. About one in two people over 85 have it. Of course, this means half don't.

  • Are you finding it harder to learn new things? That can happen normally with age, as the ability to form new memories sometimes slows. But with Alzheimer's, following multiple steps is difficult-to-impossible, and new knowledge isn't retained well because these memories don't get formed. Also with Alzheimer's, memory troubles tend to affect not just new tasks but old familiar ones as well.

  • Are you scared? The irritation of forgetting an appointment is different from the deeper fear inspired by, say, forgetting how to use the telephone, says University of Wisconsin geriatric psychiatrist Ken Robbins.

  • Are others mentioning their concern to you? People with Alzheimer's are often unaware that they're even having memory troubles -- so if you're worrying, you may be just fine, experts say.

  • Can you still pretty much carry on your everyday life? With Alzheimer's, the answer is clearly no.

Paula Spencer Scott

Paula Spencer Scott is the author of Surviving Alzheimer's: Practical Tips and Soul-Saving Wisdom for Caregivers and much of the Alzheimer's and caregiving content on Caring. See full bio