Lack of sleep may cause anxiety by making us less adaptable to threats
People kept awake overnight did not seem to habituate to a potentially threatening space the way rested people do, staying hyperalert instead. Researchers think this may help explain the two-way link between poor sleep and anxiety, since anxiety disorders are the most common mental health condition and are both a cause and a symptom of bad nights. The hyperalert response may once have protected our ancestors from predators, an evolutionary better-safe-than-sorry setting that is less useful now. It fits earlier work tying sleep deprivation to increased activity in anxiety-related brain regions such as the amygdala, and matters because around a third of adults in the West struggle with sleep at least once a week.
For you: Worth knowing that feeling jumpy and on edge after a bad night may be your brain refusing to stand down from threats, not just tiredness.
What it shows: Reported by New Scientist (home) and not verified by us: we could not trace this story to a published paper, so treat it as news rather than evidence we have checked.