You’ve heard it said before: insomniacs typically overestimate how long it takes to fall asleep and underestimate the amount of sleep we get. Time and again, sleep experts ask us to estimate our sleep time. Then they conduct overnight sleep studies with polysomnography (PSG) and find, on average, that we fall asleep faster and sleep longer than we think.
Are insomniacs just unreliable when it comes to estimating time? What else might account for this discrepancy? Should we be reassured that we’re probably sleeping more than we think?
Psychophysiologic insomnia: This was my diagnosis when I finally decided to see a doctor about my sleep. I didn’t like the sound of it. “Psycho” came before “physiologic,” and to me the implication was that my trouble sleeping was mostly in my head.
My insomnia felt physical, accompanied as it was by bodily warmth, muscle tension, and a jittery feeling inside. I was anxious about sleep, too, and my thoughts weren’t exactly upbeat. But surely putting the psycho before the physiologic was putting the cart before the horse?
When I ask people with persistent insomnia if they’ve had a sleep study, the common responses I get are these:
“I had one and all I learned from it was that I don’t have sleep apnea.”
“I want one, but my doctor won’t write the prescription.”
If you haven’t had a sleep study, you may wonder if spending the night at a sleep clinic might help the doctor understand your problem and how to fix it. Polysomnography, or PSG, is the test conducted at the clinic. New guidelines from the American Board of Internal Medicine (ABIM) clarify when PSG is useful in cases of chronic insomnia and when it isn’t. Here’s a summary and explanation of the guidelines.