Delayed sleep phase syndrome (DSPS) also known as delayed sleep phase disorder is a circadian rhythm sleep disorder where you stay up extremely late (after midnight) and have difficulty waking up in the morning. There is an inability to fall asleep at a desired time and the inability to awake at a socially acceptable time. When these patients are not required to maintain a strict schedule, patients will exhibit normal sleep quality. Unlike jet lag and the effects of shift work, the disorder is persistent.

If you or a loved one is suffering from delayed sleep phase disorder, professional advice should be sought.