Could something other than aging or dementia be to blame for my fuzzy thinking?

DEAR DOCTOR K:

Lately my mind and memory have not been as sharp as usual. Could something other than aging or dementia be to blame?

DEAR READER:

I’m glad you asked, because memory or thinking problems often lead people to worry that they are developing dementia. Most causes of dementia don’t yet have cures. However, there are several underlying conditions that often affect memory and thinking — conditions that can be cured. And they are often overlooked.

I spoke to my colleague Dr. Shreya Raj. She is a neuropsychiatrist with the Center for Brain/Mind Medicine at Harvard-affiliated Brigham and Women’s Hospital. We discussed several common and treatable underlying conditions that can impair thinking skills:

  • MEDICATION SIDE EFFECTS. Several common medications can affect thinking. Over-the-counter examples include oxybutynin (Ditropan) for incontinence and diphenhydramine (Benadryl) for allergies. Prescription medications such as amitriptyline (Elavil) for depression and cyclobenzaprine (Flexeril) for muscle spasms can affect cognitive function. Any medication that has a sedative effect, such as pain or sleep medications, may also make it hard to concentrate and think clearly.
  • LOW B12. Vitamin B12 is essential for healthy blood and nerve function. But as we age, it gets harder to absorb the B12 we get from food. This can cause abnormally low B12 levels in the blood, which can lead to fuzzy thinking and other symptoms. Fortunately, this problem is easily fixed by taking vitamin B12 pills or, sometimes, B12 injections.
  • ANXIETY OR DEPRESSION. Both anxiety and depression can cause fuzzy thinking. These conditions interfere with your ability to attend to what’s going on around you, and you feel mentally exhausted. They also can keep you from getting enough deep sleep each night. The result is impaired ability to think clearly or make a decision. By improving your concentration and your sleep, treatment for anxiety or depression can improve your mental function.
  • UNDERACTIVE THYROID GLAND. When your thyroid gland isn’t producing enough thyroid hormones, many body functions become sluggish, including brain function. This can lead to blurred thinking and forgetfulness. Treatment with a thyroid pill can fix the problem.
  • OBSTRUCTIVE SLEEP APNEA. Obstructive sleep apnea causes people to stop breathing periodically while they sleep. As a result, they don’t get enough deep sleep at night. The classic symptom is daytime sleepiness. But it can also cause fuzzy thinking. (Sleep apnea also puts you at risk for stroke and heart disease.) There are treatments that can greatly improve symptoms.

You might need some tests to identify an underlying condition. Blood tests can check your thyroid hormones or B12 levels. A sleep test can determine if you have sleep apnea.

If not, your doctor may refer you to a neuropsychologist. This specialist can put you through a series of formal tests of your thinking ability, particularly signs of dementia. Most of the time, however, people with fuzzy thinking do not have dementia. They have a less serious condition, one that usually can be successfully treated.