Not Thinking Clearly? You Might Not Be Getting Enough Sleep


Sleeping seven to eight hours a night is best for cognitive performance for most people, according to a large 2018 study in the journal Sleep.

Canadian researchers had more than 10,000 people from around the world complete online surveys and cognitive tests. Participants reported that they slept 6.4 hours per night, on average, during the past month.

When the researchers correlated typical sleep durations with the cognitive test results, they found that, regardless of age, participants sleeping seven to eight hours per night performed best, on average, especially on tests of reasoning and verbal ability; short-term memory was not affected by sleep duration. People who regularly slept less than seven hours a night and those sleeping more than eight hours were equally impaired.

If you’re having trouble getting a good night’s sleep, ask your doctor to evaluate your medications and identify any that might be contributing to sleep disturbances. Also, ask your doctor if you should be screened for sleep apnea, restless legs syndrome, or another sleep disorder.

Don’t forget these self-help tips:

  • Stick to a sleep schedule. Go to bed and wake up at the same time every day, even on weekends.
  • Use the bedroom only for sleeping or sexual activity. Remove electronic distractions like TVs, computers, and phones.
  • Exercise regularly, but not too late in the day. Avoid strenuous activity at least two to three hours before bedtime. Regular exercise is especially beneficial in calming restless legs.
  • Create a relaxing sleep environment. It should be noise-free, with a comfortable temperature, and dark.
  • Don’t lie in bed awake. Get out of bed and do something quiet like listening to soft music until you’re tired.
  • Avoid long late-afternoon naps. A nap that lasts longer than half an hour can induce grogginess and difficulty sleeping at bedtime. If you do nap, limit duration to 20 minutes, which could relieve daytime fatigue and sleepiness.
  • Avoid alcohol. A nightcap can wreak havoc on sleep patterns and leave you stuck in lighter, less refreshing sleep.
  • Pass on the nicotine and caffeine, too.
  • Skip big meals right before bed. Eating late can trigger indigestion, especially if you have gastroesophageal reflux disease, or GERD.
  • Limit beverages in the evening. Nighttime bathroom trips disrupt sleep. If frequent urination at night persists, see your doctor. You may have an overactive bladder or an enlarged prostate.
  • Lose excess weight. Being obese makes you more prone to sleep apnea.