Insomnia or Delayed Sleep Phase Disorder?

Sometimes I hear from people whose sleep problem sounds more like a circadian rhythm disorder than insomnia. Laurel wrote that she’d always been a night owl. So she was taking sleeping pills to get to sleep at night.

But if her problem is due to a delayed or sluggish body clock—if what she has is delayed sleep phase disorder (DSPD)—she’d be better off with other types of treatment. Here’s more:

Night owls are better off with bright light therapy than sleeping pillsSometimes I hear from people whose trouble sleeping sounds more like a circadian rhythm disorder than insomnia. Here’s what Laurel wrote:

 

 

 

 

I have trouble sleeping virtually every night—it is not intermittent—and I always have. I was a poor sleeper as a child, staying up until very late (3 a.m. to 5 a.m.), then being exhausted during the next school day and napping in the afternoon . . . continuing the vicious cycle. This pattern has pretty much stayed the same throughout my adult life. It seems to run in the family, as my mother had awful insomnia, as does my sister.

Laurel was taking sleeping pills to get to sleep at night. But if her problem has mainly to do with her body clock—if what she has is delayed sleep phase disorder (DSPD)—she’d be better off with other types of treatment.

Symptoms of DSPD

DSPD symptoms are similar to the symptoms of people with sleep onset insomnia:

  • Trouble falling asleep at bedtime
  • Catastrophic thinking at night (related to how their inability to fall asleep will affect their performance or interpersonal functioning the next day)
  • Poor cognitive functioning in the daytime and irritable mood

But in one fundamental way, the symptoms associated with the two disorders are different. Sleep onset insomniacs are inclined to poor sleep regardless of sleep opportunity. People with DSPD, in contrast, can generally get a good night’s sleep when allowed to sleep during the hours of their choosing (as, for example, when they’re on vacation). Their sleep problem has mainly to do with timing. School and work obligations fit poorly with their internal circadian rhythms. The result is sleep loss, poor performance, and, over time, reduced life prospects.

How DSPD Develops

It begins in adolescence. Then, for unknown reasons, children experience a biological delay in their sleep pattern. This delay causes them to want to go to bed and get up later (which is why later school start times for middle and high school students makes so much sense).

Then, as people reach the age of 20 or so, most of us start shifting backward again to earlier preferred bed and wake times. But a small number of people don’t shift back. They become night owls, and their preference to stay up till 3 and in bed till 11 can persist into middle age and beyond.

Delayed Circadian Rhythms

What keeps people like Laurel running late? Two phase markers determine when we feel like sleeping and when we’re ready to wake up. Onset of melatonin secretion is one. Melatonin secretion is negligible during the daytime but high at night, starting about 1 to 2 hours before normal bedtime. Research has shown that melatonin secretion begins about 4 hours later in people with DSPD than in normal sleepers.

The second phase marker is core body temperature. We’re physiologically alert at times when our core body temperature is high and sleepy when it’s low. Normal sleepers’ body temperature is highest—and physiological alertness, greatest—in the evening from about 6 to 9 p.m. In people with DSPD, this temperature high occurs 2 to 6 hours later.

The lowest core body temperature in normal sleepers—when people are sleepiest— occurs around 5 a.m. Research has shown that the body temperature low occurs on average over 2 hours later in people with DSPD. No wonder they can sleep right through buzzing alarm clocks.

A Longer Circadian Period

Studies have also shown that people with DSPD have longer-than-normal circadian periods. The average circadian period in humans—the time it takes to complete a full cycle—is 24 hours 12 minutes. Exposure to sunlight corrects for the 12-minute delay and keeps most of us running on 24-hour days.

The body clock in people with DSPD tends to run slow, cycling once every 25 or even 26 hours. The 1- or 2-hour advance needed to bring them into sync with the 24-hour day is harder to accomplish, say sleep experts, and likely another cause of DSPD.

Treatments

The gold standard in treatment for people with DSPD is early morning bright light therapy combined with a melatonin supplement taken around dinnertime:

  • Bright light: The light source can be the sun or a light box that disseminates light at 10,000 lux. Light exposure should occur immediately upon waking up. Two-hour sessions are most effective.
  • Melatonin supplement: Phase advances are also larger when morning bright light therapy is combined with a melatonin supplement taken late in the afternoon or early in the evening. In a recent study, 0.5 mg of melatonin taken late in the afternoon and 30 minutes of bright light therapy in the morning produced 75% of the phase shift that occurred with the 2-hour light exposure.

Q&A: Should Night Owls Use Sleeping Pills?

Rob wrote to Ask The Savvy Insomniac complaining about insomnia and wondering if Belsomra might help.

Today’s blog post features his story and my response.

Rob wrote to Ask The Savvy Insomniac complaining about insomnia and wondering if Belsomra might help.

trouble functioning in the a.m. could indicate circadian rhythm disorder

I’ve had insomnia since my teens. Never could get to sleep before 2:30. And that’s when I’m lucky. Sometimes it’s 3:30 or 4.

I do everything I’m supposed to do. I work out at the gym every day. I have a few beers when I get home but that’s it. I use a blue light blocking app on my computer and anyway I’m usually off it by 11. But nothing I do changes the situation. I just don’t feel sleepy. No matter how sleep deprived I am, I feel wired.

When the alarm goes off at 7:20 I feel exhausted. Coffee doesn’t help. I fight to stay awake at the office and by the end of the week it’s a losing battle. Early morning meetings are the worst.

What saves me is being able to sleep in on weekends. That and sleeping pills. Ambien will sometimes put me to sleep by 1. So my question is: Do you think Belsomra could work for me?

Barking up the Wrong Tree

I’m no doctor, but I suspect that if Rob were to consult a sleep specialist, his diagnosis would not be insomnia disorder but rather delayed sleep phase disorder (DSPD). The symptoms he reports are classic:

  • a preference for going to sleep several hours later than normal
  • difficulty sleeping at more conventional times
  • feeling alert, not sleepy, at night
  • struggling to wake up and function in the morning
  • catching up on sleep on the weekends

Rob might not have a sleep problem if his work began at noon. But most jobs start earlier, and for people with DSPD, trying to function on a conventional schedule is a major ordeal. It can quickly lead to sleep deprivation and trouble meeting obligations. It limits prospects down the line.

A 25-Hour Circadian Period

We humans can’t choose our sleep time preferences. Whether you’re a night owl, an early bird, or somewhere in between depends on a mix of genetic factors. These preferences can be modified, though, and may also evolve with age-related changes.

Sleep experts have long suspected that people with DSPD have body clocks that run slow, taking longer to complete their daily cycle. While the average circadian period in humans is 24 hours 11 minutes, scientists have hypothesized that the period length in people with DSPD is closer to 25 hours.

The results of two recent studies confirm that circadian rhythms are quite a bit more delayed in people with DSPD than in normal sleepers:

  1. Investigators in Australia assessed study participants’ core body temperature rhythms over 78 hours and found that under conditions of a constant routine, DSPD patients’ temperature rhythms were delayed by about one hour a day. This suggests “that DSPD patients, on average, must advance their circadian rhythm by almost an hour each day to maintain stability of their sleep–wake cycle to the 24-hour world.”
  2. Using a similar, 30-hour study protocol, the same team found that melatonin secretion began almost 3 hours later in DSPD patients than in normal sleepers. While in normal sleepers the melatonin secretion began with a surge, in DSPD patients, it started out gradually.

No wonder people like Rob have trouble getting to sleep!

Therapies: Bright Light and Melatonin

The most effective treatment for night owls wanting to get to sleep sooner is not sleeping pills but rather bright light therapy. The light source can be the sun or a light box that disseminates light at 10,000 lux. Light exposure should occur first thing in the morning. The largest phase advances occur in sessions lasting for 2 hours.

Phase advances are also larger when morning bright light sessions are combined with a melatonin supplement taken late in the afternoon or around dinnertime. Combined with 0.5 mg of melatonin taken late in the afternoon, continuous exposure to bright light for 30 minutes early in the morning was found, in another recent study, to produce 75% of the phase shift that occurred with the 2-hour exposure.

But the bright light–melatonin regimen is not a cure for DSPD. Stop it and your circadian rhythms will revert to their natural cadence. This will also happen if you allow yourself to sleep in late on weekends. You’ll function best if you maintain the same sleep-wake schedule all 7 days of the week.

As for sleeping pills like Ambien and Belsomra, why assume the risks these pills confer when bright light therapy and melatonin supplements, which have few if any side effects, can work even better?

If you’re a night owl, have you tried bright light therapy and/or melatonin supplements? How have they worked?

The ADHD-Insomnia Connection

Got ADHD? Chances are you’ve got insomnia symptoms, too. About 92 percent of the subjects in a recent study of adults with ADHD reported going to bed late because they were “not tired” or “too keyed up to sleep.”

The sleep problems of adults with ADHD may be due to delayed (and possibly less stable) circadian rhythms. If you’ve got ADHD-related insomnia, treatments aimed at advancing circadian phase may help.

too-much-to-doGot ADHD? Chances are you’ve got insomnia symptoms, too. About 92 percent of the subjects in a recent study of adults with ADHD reported going to bed late because they were “not tired” or “too keyed up to sleep.”

Results of this study, from University of Alabama at Birmingham, show that the sleep problems of adults with ADHD are due to delayed (and possibly less stable) circadian rhythms. (Circadian rhythms are controlled by the body clock.) And, say UAB researchers, delays in sleep timing—and daytime sleepiness—correlate with more severe hyperactive-impulsive and inattentive ADHD symptoms. If you’ve got ADHD-related insomnia, treatments aimed at advancing circadian phase may help.

The Larger Picture

The new findings are in line with the results of other work. Investigators have found, for instance, that ADHD is associated with differences in type or expression of these circadian genes: CLOCK, BMAL1, and PER2.

The body’s production of sleep- and wake-friendly hormones is correspondingly delayed. Investigators in The Netherlands reported in a 2010 study that secretion of melatonin—which helps with sleep at night—began an average of 83 minutes later in adult subjects with ADHD than in adults without. Production of cortisol, which helps with waking up in the morning, is also delayed in people with ADHD.

Across the board, ADHD subjects tend to fall asleep later and wake up later than subjects without ADHD. The medical diagnosis for this delay in falling asleep, when uncomplicated by ADHD, is Delayed Sleep Phase Disorder. Treatments that work for people with DSPD may work for you if you’ve got ADHD.

Better Sleep, Less Sleepiness

  • Bright Light Therapy: A two-hour exposure to bright light (sunlight, or light from a light box) immediately upon waking up every morning is the most effective way to shift sleep to an earlier hour. But this may not jibe with your morning routine. In the winter you wake up to darkness, and continuous use of a light box may not be an option if you have to care for children or get ready for work. Do the best you can by turning up lights in your home full force, and spend as much time as possible by a light box in the first few hours of the day.
  • Melatonin Supplements: Over-the-counter melatonin supplements may also help shift your sleep forward when used every day. But melatonin is not a sleeping pill. It’s effective only when taken well before your internal melatonin secretion begins. For best results, take a tablet 5 to 7 hours before your normal bedtime (rather than right before bedtime, as advised on the label).
  • Rozerem: Ask your doctor about Rozerem (or ramelteon) if you’re interested in going the prescription drug route. Rozerem, approved by the FDA in 2005 for people with trouble falling asleep, purportedly behaves like a super-melatonin. Unlike most sleeping pills on the market today, it’s not known to have many side effects. Take it half an hour before you go to bed.

Shifting circadian rhythms forward may improve your sleep, cut down on daytime sleepiness, and—possibly—help control your ADHD symptoms.

If you’ve got ADHD, how often do you find yourself too keyed up to sleep?