When do sleep terrors typically occur during the sleep period?

Sleep terrors, also known as night terrors, occur primarily during non-REM (NREM) sleep, specifically in the first third of the night. This phase includes stages 3 and 4 of sleep, also referred to as slow-wave sleep. During this deep sleep stage, individuals are more prone to experiencing vivid dreams or disturbances that manifest as sleep terrors, characterized by intense fear, screaming, and thrashing without the individual being fully awake or aware of their surroundings.

The timing is significant because, during the first third of the night, the body transitions through its sleep stages, spending a considerable amount of time in the deeper stages of NREM sleep before cycles of REM sleep begin to dominate the later parts of the night. Consequently, sleep terrors are less likely to occur during REM sleep, which predominates in the latter half of the sleep period, making it crucial to understand this timing when discussing sleep disorders and their manifestations.