The Many Causes of Memory Loss (That Aren't Alzheimer's)

by Women's Brain Health Initiative:It is understandable to worry when you experience bouts of forgetfulness. With an aging population, Alzheimer’s disease has become increasingly prevalent and a growing concern for the general public. Before hitting the panic button, however, bear in mind that there are many potential causes of memory loss that have nothing to do with Alzheimer’s.Firstly, as we age, a little forgetfulness is to be expected. In fact, according to Associate Professor Morgan Barense at the University of Toronto, some memory loss is even a good thing. “People who have good memories are often really good forgetters,” says Barense, a cognitive neuroscientist who studies how the brain forms memory. “This prioritization of remembering information that’s relevant versus information that’s irrelevant. That’s a key part of having a good memory.” One recent strand of research out of the University of California, Los Angeles, published in Developmental Psychology, found that while younger individuals had greater memory capacity, older adults were better at deciding what to remember amongst the clutter.However, in the event that you are past acceptable “senior’s moments” and feel that something is awry, it is important to look first to what is happening in your life. Have you been experiencing a great deal of stress at home or suffering under an overbearing boss at work? In 2013, Harvard Health Publications described stress, anxiety, depression, and exhaustion as the “four horsemen of forgetfulness.” While these causes can be linked to one another, they are quite distinct in terms of what they do to the body and how they lead to memory loss.Stress and anxiety, for example, have been shown over the long term to have damaging effects on the brain and on memory in particular. In a study published in 2016 in The Journal of Neuroscience, a research team out of Ohio State University tested the effects of sustained stress on the memory of mice. They found that mice repeatedly exposed to larger, aggressive mice had difficulties locating an escape hole in a maze that they had been adept at navigating prior to the exposure. The cause of the memory loss, according to the researchers, was inflammation of the brain triggered by the immune system, which was itself activated by recurrent exposures to the alpha mice.Depression could be another culprit. Severe depression can make even the most mundane cognitive processes, such as deciding what to eat for lunch, extremely difficult. An international consortium with the intriguing name of ENIGMA conducted a wide-scale study examining brain scans of approximately 9,000 men and women. The ENIGMA study, published in the 2016 issue of Molecular Psychiatry, found that depression on a recurring basis actually shrinks the hippocampus — the part of the brain responsible for forming memories. The good news, according to one of the study’s lead researchers, is that the hippocampus is one of the most regenerative areas of the brain and the effects of depression can be reversed.Stress, anxiety, and depression are all associated with another potential cause of memory loss — sleep deprivation. As most people who have experienced life with a newborn can attest, exhaustion can sometimes make it hard to remember your own name, let alone much else. A recent study published in eLife sheds some light as to what is actually occurring inside of your brain when you are not getting enough sleep. Researchers from the University of Groningen in the Netherlands and the University of Pennsylvania conducted various sleep-loss experiments with mice and found that five hours of sleep deprivation can lead to a loss of connectivity between neurons in the hippocampus — a problem in terms of remembering things because memories are stored by ensembles of neurons that communicate across the brain.A vitamin B₁₂ deficiency may also cause memory loss, but can be reversed when properly treated. As a review and case report in the Primary Care Companion to the Journal of Clinical Psychiatry found in 2009, vitamin B₁₂ – together with folic acid – is believed to ward off several disorders, including dementia. The richest sources of B₁₂ are animal and fortified foods. There are various reasons why you may not be getting enough B₁₂, including the fact that as we age, many of us stop producing enough stomach acid to release B₁₂ naturally from the food we eat. Vegans and vegetarians may also be B₁₂ deficient, as well as individuals who have had surgery on their digestive systems to aid weight loss.Memory loss may also be linked to urinary tract infections (UTIs). While UTIs impart many unpleasant symptoms upon the young, they can create an entirely different set of challenges for older adults (primarily because our immune system changes as we get older and we respond differently to various infections). Older adults with UTIs may not experience pain, and instead may show signs of confusion, agitation or withdrawal. This is a particular concern for individuals caring for a friend or family member with dementia, as these symptoms may be conflated with the condition or general decline.Another potential cause of your forgetfulness may be residing in your medicine cabinet. A number of commonly prescribed drugs have been found to be associated with memory loss. These include drugs to combat anxiety (benzodiazepines), cholesterol (statins), depression (tricyclic antidepressants), seizures, Parkinson’s disease (dopamine agonists), hypertension (beta-blockers), and incontinence (anticholinergies). Others include certain kinds of painkillers, sleeping aids, and antihistamines. Be sure to consult your doctor before reducing or eliminating any of your prescribed medications.Finally, included among the possible causes of memory loss that are not Alzheimer’s are injuries or chronic illness, which are usually irreversible. If either of these is the cause of your forgetfulness, you are likely well aware of the condition irrespective of its effect on your memory. These brain injuries may stem from violent sports, hydrocephalus or “water on the brain” (which is an excess or cerebrospinal fluid around the brain), brain tumours, subdural hematomas (blood clots caused by bruising), thyroid disease, vascular dementia, and a variety of degenerative diseases, including Parkinson’s and Huntington’s.Regardless of what is causing your memory loss, catching symptoms early remains your best defence. “The brain is this exquisitely organized, complex machine and it’s really hard to put such a machine back together once it’s started to break down,” says Professor Barense. “It’s like reconstructing the Sistine Chapel from crayons. You just can’t do it.”Source: MIND OVER MATTER