Are your sleep thoughts Sleep-Promoting, or Sleep-Disrupting?

Posted April 1, 2021 by Dr. Catherine Darley
Categories: Uncategorized

So often, in the clinic, patients share the thoughts that they have about their sleep. They are thinking things like:

  • “If I don’t start sleeping, will I get early onset Alzheimer’s?
  • “When I get home and start making dinner, I start to worry about how I’m going to sleep tonight”
  • “I can never predict whether I’ll sleep well or not”

The first-line treatment for insomnia, recommended by the American Academy of Sleep Medicine, is Cognitive-Behavioral Therapy for Insomnia (abbreviated CBT-I). A key component of CBT-I is that cognitive piece, which is focused on shaping thoughts in ways that support sleep.

It’s useful to put each sleep thought in one of two camps, either a) sleep promoting thoughts, or b) sleep disrupting thoughts. When going through the day, the first step is to catch yourself having a sleep thought, and not let it be part of your automatic mental landscape. Instead, catch yourself, and evaluate “Is this a sleep-promoting, or sleep-disrupting thought?”

If it’s a sleep-disrupting thought, then challenge it by asking “Is this really true, or is there another way to think about it?” You may be able to see cases where that thought is not always true. As soon as that realization hits, the power of the sleep disruption thought diminishes.

The next step is to intentionally think sleep-promoting thoughts. Examples could be:

            “I have overcome health challenges in the past.”

            “Most of my life I’ve slept well”

            “I’m trying a new treatment plan, which has worked for thousands of people”

            “Regardless of my sleep, I’m getting done what needs to get done”           

Of course for these intentional sleep-promoting thoughts to work in re-shaping your view, they must have the power of truth, and be true for you individually.

There’s a saying in sleep medicine: “Only insomniacs try to sleep, everyone else just sleeps.” Sleep unfortunately is one of those rare areas in life that the harder you try, the worse you do. Reshaping your sleep thoughts so that you are more confident in your sleep and therefore can step away from trying so hard can be part of sleeping well again.


The Critical Importance of Sleep for Firefighters

Posted September 11, 2019 by Dr. Catherine Darley
Categories: First Responders, overweight, performance, public safety, sleep, sleep deprivation, Uncategorized

September 11 is a day we will never forget. I am forever thankful for the firefighters and others who step forward to watch over us all as first responders.

In honor of the day, here is a summary of what we know about firefighters’ sleep, and the costs they pay to provide 24/7 service.

It is critically important that firefighters are able to perform well when they are on duty, however, a large number are impaired by inadequate sleep. Many common concerns of firefighters such as cancer and cardiovascular disease risk, barriers to physical fitness, food culture, psychological stress from trauma and injuries (1), are related to or can be improved by sleep health.

Health and Safety:

The effects of inadequate sleep on human mental and physical health have been well documented. For firefighters the leading causes of death are heart attack and auto accidents (2).

  • 51.2% of firefighters report disturbed sleep, which contributes to psychological distress (3).
  • 37.2% of firefighters surveyed screen positive for sleep disorders: 28.4% obstructive sleep apnea, 9.1% shift work disorder, 6% insomnia, and 3.4% restless legs syndrome (3). Of these, the majority (80%) have not been diagnosed or treated.
  • Those who have sleep disorders are twice as likely to have an auto accident, and 2.4 times as likely to experience falling asleep while driving. They also are at increased risk of cardiovascular disease, diabetes, anxiety and depression (4).
  • Another study found that 17% have sleep problems, and as sleep hours decreased, so did physical quality of life (5).
  • Sleep deprivation among firefighters appears to increase high-risk behaviors such as alcohol consumption and decrease mental health and physical well-being (6).
  • Compared to firefighters with 8 hours of sleep, sleep deprived firefighters show changes in both their inflammatory cells and evening cortisol levels which has been shown to have adverse health effects (7).
  • Night and extended shifts increase the prevalence of cardiovascular and mental health disorders (8).

Shift Work and Performance:

Night shift and the extended shifts typical among firefighters are inherently difficult, though improved individual sleep plans and administrative policies can improve daytime sleep and alertness at night.

  • Response time by firefighters is slowest at 5am, twice as long as at 4pm (9).
  • The risk of a work related injury peaks at 2am (10).


Firefighter injuries in the U.S. are estimated to cost $3.7 to 11.7 billion per year (11). Sleep deprivation is known to contribute to obesity via changes in appetite hormones, calorie intake and the insulin system. Obese firefighters miss five times as many work days as those of normal weight, at an annual cost of $1683 per employee (12), and those with BMI >30 have a three times increase in worker compensation claims due to injury (13).

Public safety personnel need to be able to perform well at all times of the day and night, however firefighters are not getting adequate sleep to perform well, make good judgments, or maintain their physical and mental health. Implementing wellness and fitness programs has been shown to improve cardiorespiratory endurance, experienced health and job satisfaction, while decreasing weight, high blood pressure and anxiety(14). Providing expert-led sleep and fatigue management education to firefighters will assist in achieving a higher level of sleep health(15) and safety on the job. A simple sleep education and screening program for firefighters resulted in a 46% decrease in disability days, and 24% decrease in injury reports (16).

The Cost of Workplace Fatigue

Posted February 26, 2019 by Dr. Catherine Darley
Categories: driving safety, fatigue, health education, optimal sleep, performance, public safety, shiftwork, sleep deprivation

Last week, in Seattle, the National Safety Council put on their first Workplace Fatigue Conference, aimed at bringing fatigue experts and corporations together to solve the nation’s fatigue problem.

And no, it’s not overstating the case to say we have a fatigue problem. The costs we pay for being sleep deprived are staggering, here’s a look:

  • Untreated sleep disorders cost up to $3500/employee
  • Direct costs $14B, indirect costs $28B
  • Employees sleeping only 6-7 hours nightly cost employers 3.7 days of lost work
  • Costs come from absenteeism, presenteeism, accidents, injuries and healthcare

A large employer here in my hometown, Seattle, is Amazon. I put their data into the NSC Fatigue Cost Calculator *. Here’s the findings:

  • Fatigue is costing Amazon $47,393,505 per year
  • $6.2M in absent employees
  • $27.8M in decreased productivity
  • And $13.3M in increased health care costs

But this is not the true total cost. There are additional costs resulting from the way sleep deprivation impairs positive human interactions. When sleep deprived, leaders are more abusive and unable to see sleep deprivation in their employees, employees in turn are less satisfied with their jobs, leading to costly employee turnover. There are many other ways that sleep deprivation and sleep disorders raise costs on corporations.

I encourage you to complete the Fatigue Cost Calculator for your own corporation, then take steps by training employees on sleep health, and designing your shift schedule and other safety practices to decrease fatigue. And decrease costs will follow.


NSC Fatigue Cost Calculator

*(Assumptions were: 24,000 employees in Washington, computing sector, no shift work. Though of course we know that these employees do work long and sometimes irregular hours).

Seattle Sleep Community Urges School Board to Vote Yes

Posted November 3, 2015 by Dr. Catherine Darley
Categories: Uncategorized

Tags: , ,

The Seattle sleep community encourages the School Board to vote “yes” on the revised Bell Times and Transportation proposal at their Nov 4th meeting.  Here is the text of the letter that will be delivered during the public testimony.

Seattle School District Attention: Board of Directors MS 11-010 PO Box 34165 Seattle, WA 98124-1165

November 2, 2015

Dear SPS Board of Directors,

As local sleep specialists, we support the revised Bell Times proposal, and urge you to vote “yes” on November 4th, for implementation in fall 2016.

The American Academy of Pediatrics and the Centers for Disease Control and Prevention have recommended that secondary schools start at 8:30am or later.  This recommendation is based upon conclusive research that with puberty the circadian rhythm shifts later, making it virtually impossible for teens to get the recommended 8.5-9.5 hours of sleep nightly before getting up for early school hours.  Later school bell times have been shown to increase the total weekly sleep in teens, and thereby improve learning, performance, health and safety.

The current proposal is a profound improvement over current Seattle school hours, with 100% of high schools and 90% of middle schools starting at a healthy bell time.  It also decreases significantly the number of schools in tier 3, a time that is inconveniently late for many families.  Although you may hear from a few families who struggle with the time their child attends school, this is an important public health advance that supports the health and learning of the vast majority of secondary school students.  We thank you for the diligent efforts on the part of yourselves and the district staff to engage the community in finding this solution.

Thank you for your work to align school schedules with optimal learning times thereby improving Seattle students’ academic success, health and safety.


Sleep Specialists in the Seattle area

Seattle’s Early School Start Times – personal experience

Posted December 20, 2014 by Dr. Catherine Darley
Categories: Uncategorized

It’s 9am Saturday as I write this. My middle school student is still sleeping, despite the household noises. Yesterday, and every school day, she would be finishing math and be headed into science class in 10 minutes. Both essential subjects to master. Yet difficult to master at a time you’d naturally be sleeping.

Over the last 2-3 decades lots of research has demonstrated that puberty shifts natural sleep times later, that secondary students are largely sleep deprived because of early school start times, and that with later school start times students get more sleep, which improves academics, health and safety. You can learn more about this topic at and

Since spring of 2012 thousands of Seattlites, Wa and Seattle PTA, teachers, school nurses, and sleep specialists have asked the Seattle School District to start secondary schools at 8:30am or later, evidence based times. After 2+ years, the district has established a “Bell Time Analysis Task Force” which will look at the issue and make a recommendation to the superintendent in June 2015, for possible implementation fall 2016. As they slowly move on this community-led initiative, the approximately 23,000 secondary students are struggling with sleep deprivation each and every day.
(She woke up now, 9:05am – time for science on a regular school day).

My daughter and family are negatively impacted by Seattle’s early school start times, here’s how:
– My daughter can’t fall asleep at the time she needs to to get enough sleep (9pm for a 6:30am wake-up). She often gets frustrated in the night, and asks for sleep medication. AT 11 years old, it’s a bad sign for her to think she can’t get to sleep on her own and needs medication! What she’s done a couple times this week is to get into bed with me after a couple hours of not being able to fall asleep on her own. She hasn’t gotten into the ‘big bed’ for years! This disturbs my own sleep, and causes sleep deprivation which impacts my day and the people I interact with.
– Getting woken up when she’s still sleepy often sets us up for negative interactions between us and feeling rushed in the morning.
– She’s been sick a lot, missing two full weeks of the 15 weeks this fall. Remember, sleep deprivation impairs immune function.
– It is now so dark at commute time that I drive her for safety, so she misses out on the exercise she needs to get by walking to school. (A child at her school was hit by a car yesterday on the walk to school. She was grazed by the side view mirror, and foot run over by the rear tire).
– At the beginning of the school year she often needed a nap after school, and now needs one on weekends, which cuts our ability to have activities with family and friends. She’s socializing less with her friends.
– When my parents retired they moved into Seattle to be near the grandchildren. It’s been a nice routine over the last years to have family dinner with the grandparents and my brother’s family on Fridays twice a month. Now we no longer can meet because my daughter is so exhausted by Friday afternoon that she is in tears and can’t politely interact with the family. Now the grandparents and cousins feel disconnected and our family ties are weakened.

From this personal experience, I see that the Seattle School Districts slow implementation of evidence-based school start times has a negative ripple effect throughout our community. In our family life alone the impact is felt by: the student, parents, grandparents, cousins, student’s friends, parent’s circle of interactions. That’s a lot of people negatively impacted by one student getting up too early (7 directly, plus more indirectly)!

How are the current early start times in Seattle’s secondary schools impacting your family and community?

Record of natural wake times on winter break:
Saturday 20th wake time 9:05a
Sunday 21st wake time 8:55a

Light Impacts Sleep

Posted November 7, 2014 by Dr. Catherine Darley
Categories: body clock, circadian rhythm, Light therapy, optimal sleep, sleep

Tags: , , ,

Now that the nights are longer, it’s time to think about the impact light has on our sleep. And oh, does it have impact! This last month it’s been a pleasure to read two books on light, and human’s historical experience of night – The End of Night by Paul Bogard, and At Day’s Close Night in Times Past by A. Roger Ekirch. Let’s dive into some of the details, and then how you can design light exposure to help your sleep.

The negative effect of light at night
Roger Ekirch talks about the human experience of night over the centuries. Streets until the 1600s had only the light spilling from homes to light them. To be out at night was dangerous, and many towns would close their doors at night and enforce a curfew. For safety, fires and candles would be put out before bed. Their use would be conserved to save money, so some poor people would go to bed soon after dark.

Compare that history to the “sky glow” that many of us are now living in, where we can hardly see the stars at night. In The End of Night author Paul Bogard outlines what is lost when we no longer have dark nights. Not only is human physiology influenced, but migrations of birds and the life-cycle of trees is altered.

Melatonin is a hormone secreted by the pineal gland of the brain. Melatonin is nicknamed “the hormone of darkness,” and helps us feel sleepy at bedtime. Unfortunately melatonin is very sensitive to light, particularly blue light, which suppresses it’s release. And what are 90% of us exposed to during the evening? The blue light of electronics which suppresses melatonin!

The positive effect of light during the dayA recent study compared the sleep of office workers who get natural sunlight to those who work on the interior of the building and don’t. Those who got more light during the work day had better sleep quality, slept longer, and had more physical activity. They also reported a higher quality of life – something we’d all like!

Using light exposure to improve sleep
The basic principle is to get historical light levels during both day and night. In other words, bright full-spectrum light it the morning and during the day, then full darkness at night. How can you do that? Here are some ideas:
– in the morning get some bright outdoor light as soon as possible. Maybe go stand on the porch and look out while having your morning tea.
– continue to get bright light in bursts throughout the day
– in the evening, have lights low, and use the yellow-red spectrum if possible (rather than blue or full-spectrum lights). Avoid electronics for the hour before bed.
– if you are up in the middle of the night, again have low lighting. Particularly troublesome in many homes are the bright bathroom lights, instead put a small night-light in the bathroom to use if need be.
– watch out for your neighbors too by turning off outside lights that aren’t truly needed, and if you need outdoor lights, aim them downward so you are not committing ‘light trespass.’ (Interestingly, Bogard cites studies showing that increased lighting does not decrease crime, that criminals like to work in a well-lit area just like everyone else!)

Be purposeful about making all of these lifestyle changes at the same time. Then notice after a week or two how your sleep has changed!

The Problem with Alarm Clocks

Posted April 8, 2014 by Dr. Catherine Darley
Categories: bedroom, optimal sleep, sleep

Beep-Beep. Beep-Beep. Beep-BEEP. BEEP-BEEP. BEEEP-BEEEEP!

Using the alarm clock each morning to wake up is common for many Americans. It’s a practice that is hard on sleep, and a practice I’d like to do away with for everyone. Here’s some of the problems.

– If you are waking to the alarm, you haven’t gotten enough sleep. Most adults need a solid 8-9 hours of sleep nightly, and there are many negative consequences of being sleep deprived (see the video mentioned in the last post). Allowing yourself to wake on your own helps ensure that you are getting enough sleep.
– If you wake to the alarm, you may be woken out of deep sleep, or “slow-wave” sleep. This can leave you feeling groggy and take some time to “get with it” mentally.
– A feature many people use is the snooze button, giving themselves another 8-10 minutes of rest before the alarm goes off. Really it is disrupting your sleep for 10-20-30-40 minutes before you have to get up, making that sleep much less restorative.

So here’s my recommendations:
– If you’re waking to an alarm, move your bedtime earlier by 15 minutes every 4-5 days until you are waking up on your own at the time you need to. Alternatively, you can shift your committments later so that you can sleep later in the morning.
– Set the clock for the time you truly need to get out of bed. Then place it across the room so you have to be out of bed to turn it off. This will help you avoid the snooze button, and really get quality sleep until it’s time to get up.

Think about this for yourself, and for your kids too. If you are waking your children up for school they’re not getting enough sleep either.

Great video on Sleep Deprivation

Posted April 3, 2014 by Dr. Catherine Darley
Categories: Uncategorized

Over the years I’ve written a lot about sleep deprivation and it’s effects.  Primarily because Behaviorally Induced Insufficient Sleep ie, chronic partial sleep deprivation, is the most common sleep problem, affecting 47% of adults in America.

Right now I’m working with a group of shift workers to help them create a lifestyle that promotes healthy sleep on work nights and days off, and optimal alertness when awake.  People can be very motivated to work nights because of the increased pay, and often shorter work week because of longer, 12 hour shifts.  But trying to sleep during the day is hard, and often shift workers are sleep deprived.  To help them stay motivated to get enough sleep, I’ve been teaching them about the negative impact of sleep deprivation.  This excellent youtube video about “25 scary and surprising effects of sleep deprivation” by List25 tells it well.  Enjoy!


Reducing Night Nurse Fatigue

Posted March 30, 2014 by Dr. Catherine Darley
Categories: body clock, circadian rhythm, public safety, Seattle, shiftwork

Lately it’s been a pleasure to provide an intervention program for night-shift nurses to help them sleep well during the day, and thereby improve their alertness at night. For many nurses working nights a typical shift is 12 hours, often from 7pm to 7:30am. This requires them to function well during the hours that human beings are designed for sleep. Many of these employees like to sleep during the night on a similar schedule to their loved ones when not working, which keeps them in a perpetual state of circadian misalignment, making it even more difficult to function well at night.

In December 2011 the Joint Commission issued Sentinel Event Alert #48 on the effect of extended work hours and cumulative work hours on patient safety and nurse health. They summarize the extensive research on the performance effects of working at night. Some of the results of fatigue include:
– impaired information processing and judgement
– inability to focus attention
– reduced motivation
– loss of empathy
Fatigue among healthcare workers increases the risk of adverse events, decreases patient safety, and negatively impacts the health of the night shift workers.

The Commission report goes on to suggest steps organizations take to improve employee alertness and thereby improve patient safety. Fatigue management typically includes steps for both individual employees and the administration. Sleep training for employees so they can sleep well during the day, and entrain their circadian rhythm to the schedule, is one step. Another is fatigue reducing strategies such as precisely-timed caffeine and light to increase alertness on the job. Administrations can optimize their scheduling practices, and provide an alerting work environment. You can see the full Sentinel Event Report of the Joint Commission here:

Over the next 6 months I hope to continue this work for Seattle-area hospitals, and expand to help other public safety organizations that are providing 24/7 service, including the police and fire departments. Around the clock service is a must for public safety, and helping these night-shift staff to sleep well during the day, so they can be alert and healthy during the night is extremely rewarding!

Sleep Impacts Cancer

Posted February 6, 2014 by Dr. Catherine Darley
Categories: cancer, insomnia, sleep

We have become a 24-hour society where people can work, shop and exercise at all hours of the day or night. But just because we can, does that mean we should?

Humans evolved in a rhythmic world, with daily and seasonal variations in light, temperature, and food availability. In our modern world we can control all these environmental factors so they are the same throughout the year, but our body is still programmed for circadian variation. Cancer incidence increases when people live out of sync with natural rhythms, like those who do shift work.

Shift Workers at Increased Cancer Risk

Those people who work graveyard shift have an increased risk of breast cancer. This risk increases with the number of years graveyard shift has been done. Getting bright light at night suppresses our natural melatonin surge. Melatonin is a powerful anti-oxidant, protecting our cells from damage.

Shift workers also are at increased risk for:
•Cardiovascular disease
•Duodenal ulcer
•Elevated stress hormones
•Menstrual irregularities

Cancer Causes Sleep Disruption

The sleep – cancer relationship goes both ways. For those people undergoing cancer treatment, sleep disruption can be a symptom. This can be a side-effect of chemotherapy, or of pain, or other factors.

The good news is that several studies have shown that sleep of cancer patients can be improved by doing Cognitive-Behavioral Therapy for Insomnia. Specifically, after treatment, cancer patients ended up sleeping a higher percentage of the time they were in bed, had improved mood, and decreased fatigue. Another study additionally found that the people had fewer nights on medication, and that the improvements were maintained for 12 months afterwards.