Researchers have found that the type of sleep most apt to calm and reset the anxious brain is deep sleep, also known as non-rapid eye movement (NREM) slow-wave sleep, a state in which neural oscillations become highly synchronized, and heart rates and blood pressure drops.
A sleepless night can trigger up to a 30 per cent rise in anxiety levels, researchers from the university of california said. In a series of experiments using functional MRI and polysomnography, among other measures, researchers scanned the brains of 18 young adults as they viewed emotionally stirring video clips after a full night of sleep, and again after a sleepless night.
Anxiety levels were measured following each session via a questionnaire known as the state-trait anxiety inventory. After a night of no sleep, brain scans showed a shutdown of the medial prefrontal cortex, which normally helps keep our anxiety in check, while the brain's deeper emotional centres were overactive. After a full night of sleep, during which participants' brain waves were measured via electrodes placed on their heads, the results showed their anxiety levels declined significantly, especially for those who experienced more slow-wave NREM sleep.