Delayed sleep phase syndrome (DSPS) is a type of circadian rhythm sleep disorder. It’s also known as delayed sleep phase disorder or delayed sleep-wake phase disorder.

DSPS is a problem with your internal body clock. If you have DSPS, you can’t fall asleep at a socially acceptable bedtime. Instead, your sleep is delayed by at least two hours. This happens even when you’re tired.

The delay can make you wake up later, which might interfere with work, school, and other daily routines.

DSPS is common. It can develop at any age, but it mostly affects teenagers and younger adults. Approximately 15 percent of adolescents and adults have DSPS.

The condition isn’t the same as being a “night owl.” If you’re a night owl, you choose to stay up late. But if you have DSPS, you’re up late because your body clock is delayed.

Difficulty falling asleep

DSPS makes it hard to fall asleep at a conventional bedtime. The delay in your internal clock tells your body to stay alert.

Typically, you won’t be able to sleep until several hours after midnight, between 2 a.m. and 6 a.m.

Sleeping difficulty can get worse if you try to stay up to do homework or socialize.

Difficulty waking up

Because you can’t get to sleep until late, DSPS also makes it hard to get up at a normal time. This is because your internal clock hasn’t started telling your body to wake up.

You might sleep well into the late morning or afternoon.

Excessive daytime sleepiness

Daytime drowsiness occurs when you can’t fall asleep but need to wake up at a certain time. During the day, you might find it difficult to focus and pay attention.

Even if you fall asleep early, DSPS may prevent you from getting enough deep sleep. This can make you feel excessively tired throughout the day.

No other sleep issues

Usually DSPS isn’t accompanied by other sleep problems like sleep apnea.

Unless it’s interfering with daily activities, you may generally be getting enough quality sleep — it’s just delayed. Additionally, when you fall asleep, you have no problems staying asleep.

The problem is when you can sleep and wake up.

Depression and behavior problems

If you can’t keep a normal sleep schedule, you may develop depression due to stress.

Daytime sleepiness can also interfere with work or school. You might show up late, miss days, or have a hard time paying attention. Children and teenagers with DSPS may experience poor academic performance.

DSPS can also lead to a dependency on caffeine, alcohol, or sedatives.

While the exact cause of DSPS isn’t known, it’s often associated with several factors.

These include:

  • Genetics. If you have a close relative with DSPS, you have a higher chance of developing the condition. Forty percent of people with DSPS have a family history of the disorder.
  • Changes after puberty. During adolescence, the body’s 24-hour sleep cycle becomes longer, which requires later sleep and wake times. Adolescents also tend to become more social and take on more responsibilities.
  • Psychological and neurological disorders. DSPS is linked to conditions like:
  • Chronic insomnia. DSPS affects 10 percent of people with chronic insomnia.
  • Poor sleeping habits. DSPS symptoms can get worse if you don’t get enough light exposure in the morning. Symptoms might also increase if you’re exposed to too much light at night.

DSPS isn’t the same as being a night owl.

If you’re a night owl, you might purposely stay up to do homework or socialize. You’ll also wake up later than usual.

But when it’s time to follow a normal routine, you’re able to adjust your sleep schedule.

If you have DSPS, you don’t try to stay up late. Instead, your internal clock delays sleep even if you’re tired. It may be difficult to adjust your body clock, which makes it difficult to sleep and wake at normal times.

DSPS is often misdiagnosed.

This is because many people with DSPS force themselves to follow a normal routine. So, if you’re constantly fatigued, you might be misdiagnosed with depression. If you report problems falling asleep, you might be misdiagnosed with insomnia.

If you or your child has sleep issues, talk to a sleep specialist. You should also see a doctor if you have delayed sleep for at least seven days.

A sleep specialist can do different tests to determine if you have DSPS.

This might include the following:

  • Gathering medical history. This helps your doctor understand your family history and symptoms.
  • Request a sleep log. Your doctor might have you write down when you fall asleep and wake up each day. If you’d like, come prepared to your first appointment with a sleep log.
  • Actigraphy. You’ll wear a wrist device that tracks your sleep-wake patterns. This test is best done when you’re off from work or school, because you won’t need to wake up for various responsibilities.
  • Polysomnogram. If your doctor thinks you have a different sleep disorder, they might request an overnight sleep test called a polysomnogram. As you sleep, the test will monitor your brain waves and heart rate so your doctor can see what your body does during sleep.

Generally, DSPS treatment involves more than one method.

The purpose of treatment is to normalize your sleep schedule by adjusting your body clock.

Your doctor will choose the best treatments for your symptoms and lifestyle. This might include:

  • Advancing your internal clock. Each night, you’ll go to bed about 15 minutes earlier. You’ll also wake up a bit earlier each day.
  • Delaying your internal clock. Also known as chronotherapy, this method involves delaying your bedtime 1 to 2.5 hours every six days. This is repeated until you can follow a normal sleep schedule.
  • Bright light therapy. After waking up, you will sit near a light box for 30 minutes. The morning light exposure can help you sleep sooner by advancing your internal clock.
  • Melatonin supplements. Your doctor might have you take melatonin, a hormone that controls your sleep-wake cycle. The best amount and timing is different for each person, so it’s important to follow your doctor’s exact instructions.
  • Improving sleep hygiene. Good sleep habits include following a regular sleep schedule and avoiding electronics before bedtime. You should also avoid these things before going to sleep:
    • caffeine
    • alcohol
    • tobacco
    • vigorous exercise

Usually, a teen who has DSPS won’t grow out of it.

DSPS often continues into adulthood, so it needs to be actively treated.

The initial treatment will adjust your body clock. But to maintain that change, you’ll need to continue treatment.

Your doctor can explain the best way to keep treating DSPS.

Delayed sleep phase syndrome (DSPS) is a body clock disorder. Your sleep cycle is delayed, so you can’t fall asleep until two or more hours past the “normal” bedtime.

DSPS isn’t the same as being a night owl. If you have DSPS, you don’t choose to stay up late. You can’t fall asleep even when you’re tired.

With your doctor’s help, you can get your sleep back on track. Treatment aims to change your body clock with bright light therapy, melatonin, and good sleep hygiene. It might also involve adjusting your sleep and wake times.

DSPS is most common in teenagers, but it can happen at any age. Talk to your doctor if you or your child is having sleep issues.