What To Know About Delayed Sleep Phase Disorder

If you or your teen stay up until 3 a.m., there may be a medical explanation. Learn more about DSP [whichever letter] and how to treat it.

Teenager asleep and wrapped in a blanket
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If your teenager is a night owl who sleeps well into the day, there might be a very good reason. Though many teens naturally have a later circadian rhythm, a particularly late sleep schedule could be due to delayed sleep-phase disorder (DSPD).

DSPD is a circadian rhythm disorder that pushes back typical sleep and wake times by at least two hours. Though it affects approximately 13% of adults, it’s far more common in teenagers, impacting up to 16% of adolescents.

Instead of feeling sleepy at 10 p.m. — considered an optimal bedtime in a recent study — those with DSPD may stay up well past midnight, sometimes by many hours. Because of that later bedtime, they may have significant difficulty waking up for work or school.

“People with DSPD have difficulty going to sleep at the bedtime that is desired or necessary to get adequate sleep,” explains Dr. Michelle Caraballo, a pediatric pulmonologist and sleep specialist at UT Southwestern Medical Center. “They are often unable to fall asleep at the desired bedtime even when other factors (social media use, homework load, social demands, etc.) are taken away because their body’s natural circadian rhythm is to go to sleep very late and sleep very late. People with DSPD do not need more sleep than a typical person their age; their body simply prefers an alternative schedule that often does not fit the daytime demands of school or work hours.”

Symptoms of DSPD

The two main symptoms of DSPD are an inability to fall asleep at a conventional bedtime and difficulty getting up at a traditional time. Other signs of DSPD include:

  • Daytime drowsiness, especially when the person must get up without having adequate sleep. According to research published in the Journal of Thoracic Disease, when people with DSPD are allowed to sleep according to their own internal clocks, their sleep duration and quality are normal.
  • Depression. According to research published in BMC Psychiatry, depression was twice as likely in young people with delayed sleep onset than among the general population and among young people with other mental health disorders. “Sleep is essential for maintaining mental and emotional well-being,” says Dr. Meeta Singh, a psychiatrist and sleep scientist. “Chronic sleep disturbances, like those experienced in DSPD, can negatively impact mood and contribute to the development or exacerbation of depressive symptoms. Individuals with DSPD often struggle to maintain a socially acceptable sleep schedule, which can lead to difficulties in school, work, or social relationships. This can result in feelings of isolation, low self-esteem, and depression.”
  • Attention-deficit hyperactivity disorder (ADHD). People with ADHD tend to have more problems with sleep, including DSPD. According to researchers’ writings in the journal Nature and Science of Sleep, this may be because those with ADHD can lack impulse control, making it harder for them to settle into sleep at night. It also may be because those with ADHD tend to have delays in the secretion of melatonin, a naturally occurring substance that increases as darkness approaches, helping to bring on sleep.
  • School absences. One study showed that children with DSPD miss about twice as much school as children without the sleep condition.

What causes DSPD?

Experts aren’t exactly sure what causes DSPD, but they do suspect that a combination of factors — from genetics to the environment — can influence its development.

While DSPD can overlap with other sleep conditions, such as insomnia, for the most part, people with DSPD sleep well when allowed to adhere to the sleep schedule that feels most natural to them.

Some risk factors include:


Adolescents and young adults are far more prone to developing DSPD for a variety of reasons.

“During puberty, there’s a natural shift in the circadian rhythm known as sleep-phase delay,” says Singh. “This means that adolescents' internal clocks make them feel sleepy later at night and more alert in the late afternoon and evening. What’s more, teenagers often face social pressures to stay up late, such as engaging in social media, chatting with friends, or attending events. These activities can contribute to delayed bedtimes and reinforce night owl tendencies.”


Nearly 50% of people with DSPD have a relative with the condition, according to research published in Chronobiology International.

Light exposure, particularly to blue light: Scientists know that exposure to blue light — like the kind emitted from computers, TVs, and smartphones — can suppress melatonin production. “And that can interfere with the circadian rhythm and contribute to the development or exacerbation of DSPD in some individuals,” says Singh.

Treating DSPD

If your health care provider suspects a circadian rhythm disorder like DSPD, they’ll most likely have you wear a sleep tracker or maintain a sleep log, tracking when you’re asleep and when you’re awake. They may even suggest a sleep study to rule out other possible causes of your sleep issues, such as sleep apnea.

The good news: Many cases of DSPD are resolved by the time a person reaches their 20s. And in the meantime, there are effective treatments to try, sometimes in combination. These treatments include:

  • Chronotherapy. This is a behavioral technique that involves consistently pushing bedtime forward until the desired bedtime is achieved. For example, a person who is used to a bedtime of 4 a.m. will be instructed to stay up until 5 or 6 a.m. and then sleep for eight hours. The next night they stay up to 7 or 8 a.m. and then sleep another eight hours. “You continually march them around the clock until they reach their goal bedtime,” says Caraballo. “And then they have to stick strictly to the schedule, so they don’t revert to their old bedtime.”
  • Melatonin. While there is no consensus on how much melatonin to use or when to use it, a general recommendation is between 3-5 mg per night, taken 1.5 hours before the desired bedtime. Before starting, check with your doctor for guidelines specific to your situation. “The exact timing and dose of melatonin should be discussed with a sleep doctor because taking it at the wrong time can actually shift the clock in the wrong direction, causing more of a delay,” says Caraballo.
  • Light therapy. Exposing yourself to bright light in the morning can help reset your circadian rhythm, allowing you to feel more tired in the evening. “The body is particularly sensitive to light in the morning, and exposure to bright light during this time can help advance the sleep-wake cycle, making it easier to fall asleep earlier and wake up earlier,” says Singh. Experts at Stanford Health recommend getting light exposure as soon as possible after waking up. Natural sunlight or artificial indoor light at 10,000 lux (a unit of illuminance equivalent to full daylight) will do. Even 15 minutes can make a difference, but more time can mean more effectiveness, so many people aim to get 30 to 90 minutes.
  • Sleep hygiene. Creating an environment conducive to sleep can help any number of sleep conditions, DSPD included. Some tips: Make sure your bedroom is dark and comfortably cool, turn off electronics at least one hour before bed, and stick to a consistent sleep schedule, even on weekends.