To many insomnia sufferers, the prospect of sleeping 7 hours a night sounds great. Insomniacs who write to me with news that they’ve achieved this feat after undergoing some type of insomnia treatment are thrilled.
Other people are not so thrilled about 7-hour nights. No matter how long they sleep, they wake up feeling unrested. Insufficiently refreshing sleep is the main symptom of people diagnosed with nonrestorative sleep.
A Closer Look at What Nonrestorative Sleep (NRS) Feels Like
Jeremy wrote to me recently complaining of insomnia. But the way he described his problem was different from the insomnia stories I usually hear:
I do not struggle with sleep onset at all or awakening from sleep. But the ‘sleep’ I do receive is of such low quality it feels like I did not sleep at all. . . . I am often unconscious for 6 to 7 hours. But it feels like I receive practically nothing (the most similar feeling I have ever experienced is being extremely hung over from excessive alcohol consumption).
To “receive practically nothing” after a full night’s sleep makes Jeremy’s situation sound rather desperate. Normal sleep affords many benefits: it allows for the conservation of energy, enables the growth and repair of body tissue, shores up important memories and prunes the unimportant ones, enables the processing of emotion, improves our ability to perform tasks and procedures. Importantly, a night of sound sleep primes us to meet the demands of the day ahead. If Jeremy’s waking up feeling unrested, then even though he’s sleeping, he’s really missing out.
A Subjective Diagnosis
The causes of NRS are still unknown and no objective tests for it exist. Identifying its biological markers is a project only just begun. So the diagnosis of NRS is subjective, based on symptoms alone.
In 2013 Canadian investigators published an NRS questionnaire after identifying 4 key features of the disorder. Compared with healthy sleepers, people with NRS tend to:
- Experience poor quality sleep and wake up feeling unrested
- Have more aches, pains, and medical problems, including symptoms of panic
- Experience impaired daytime functioning (e.g., experience low energy and alertness, and have trouble with memory and concentration)
- More often feel depressed and/or irritable during the day
Is It Insomnia or Not?
Sleep experts have tossed this question around for years. The daytime symptoms of NRS are similar to those associated with insomnia (although the impairment caused by NRS may actually be more severe). Also, overnight sleep studies of people with NRS often look the same as those of normal sleepers, suggesting that NRS might have something in common with paradoxical insomnia, a diagnosis often given to people whose sleep studies look normal but who feel like they’re only getting an hour or two of sleep a night.
But the differences between NRS and insomnia may prove to be more important and argue for NRS to be considered a separate sleep disorder. Unlike people with insomnia, who report trouble falling asleep or staying asleep, many people with NRS experience neither of these nighttime problems.
Funded by a grant from the National Institute of Mental Health, a team of researchers looked for differences between the symptoms of insomniacs and people with NRS in large sample of the general population. They noted the following:
- The prevalence of insomnia increased with age; the prevalence of NRS decreased with age.
- Insomnia was significantly associated with cardiovascular disease; NRS was not associated with CVD but was significantly associated with different medical problems, including emphysema, chronic bronchitis, habitual snoring, sleep apnea, and restless legs syndrome.
- After adjusting for confounding factors, levels of C-reactive protein, a marker of inflammation, were significantly high in people with NRS only but not in people with insomnia only.
The elevated levels of C-reactive protein might be clue about the causes of NRS. “Indeed,” the authors write, “NRS is a core symptom of chronic fatigue syndrome and some forms of major depression, both of which have been shown to be associated with increased . . . inflammatory markers.” For anything more definitive, we’ll have to wait and see.
How Is NRS Treated?
The medical literature is sadly lacking here. If you think you might have NRS, consult a sleep specialist and see what he or she recommends. NRS often occurs in conjunction with another medical problem, such as fibromyalgia or sleep apnea, or a psychiatric problem such as depression. Treatment of that problem may improve sleep quality and help to resolve the issue with NRS.
Some research has also shown that the sleep of people with NRS is characterized by increased alpha wave activity, a phenomenon associated with hypervigilance. If this is true, then vigorous daily exercise may help.