Researchers use a method called polysomnography to measure the quality, duration, and patterns of people's sleep. The word polysomnography derives from three roots: the Greek word "poly," which means many, the Latin word "Somnus," which means sleep. And the Greek word "graph," which means to write.
When sleep researchers do sleep studies using polysomnography, they measure the brain activity, eye movement, heart rate, oxygen levels, and muscle activity of sleepers. This complex data collection enables sleep researchers to determine precisely when someone falls asleep and wakes up and tracks their cyclical journey through the different sleep stages.
From time to time, sleep researchers encounter a conflict between polysomnography data and a patient's self-reported sleep. The patient swears he's been awake most of the night, but data from the polysomnogram shows that he's been asleep the whole time. Or the patient complains about not falling asleep, but the data tells a different story. While this may sound contradictory, the patient is not lying, and the polysomnography machine is not malfunctioning. This discrepancy between subjective perception and objective measurement of sleep is a known phenomenon called paradoxical insomnia (or sleep state misperception).
Patients with paradoxical insomnia often underestimate their actual sleep time and genuinely believe they have slept very little or not at all. However, these patients remain fully functional and do not experience a reduction in functional performance the day after having reported poor or limited sleep. So, the paradox is actually visible in their day-to-day functioning. They do not display the cognitive impairment that would go hand-in-hand with the levels of sleep deprivation they report.
What causes paradoxical insomnia?
It's theorized that paradoxical insomnia has a strong correlation with a type of anxiety that is rooted in a fear of not sleeping enough. When you constantly worry about sleep and the consequences of sleep deprivation, the brain interprets this worry as something dangerous and, in response, activates your arousal system. When you finally nod off, your sleep is light because your mind is still active, and your alertness levels are high. You remain in a state of hypervigilance, despite being asleep. The light sleep, induced by hypervigilance, is then misinterpreted as wakefulness.
How does one treat paradoxical insomnia?
Paradoxical insomnia can be treated effectively with cognitive-behavioral therapy for insomnia (CBT-I). CBT-I is recommended as the first-line treatment for insomnia by the American Academy for Sleep Medicine and the European Sleep Research Society. CBT-I works because it gradually changes the way you think and feel about sleep. It helps you understand the paradox between perception and observation and improves your ability to discriminate between appearance and reality. This self-awareness gradually reduces anxiety about sleeplessness and resolves the paradox at a cognitive and emotional level.