What Is the Circadian Rhythm?

Often referred to as the "body clock", the circadian rhythm is a 24-hour cycle that tells our bodies when to sleep and regulates many other physiological processes. This internal body clock is affected by environmental cues, like sunlight and temperature. When one's circadian rhythm is disrupted, sleeping and eating patterns can run amok. A growing body of research is examining the adverse health effects a disrupted circadian rhythm can have, like increasing the chances of cardiovascualr events, obesity, and a correlation with neurological problems like depression and bipolar disorder.

Recent Posts on Circadian Rhythm

Interminable Terminal Insomnia

By Michael Terman Ph.D. on January 08, 2016 Chronotherapy
How does a clinical social worker proficient in sleep hygiene cope with persistent terminal insomnia? Abigail details her struggle with her least favorite symptom of SAD.

Exercise Improves Sleep, but Maybe Not How You Think

By Seth J. Gillihan Ph.D. on January 05, 2016 Think, Act, Be
Aerobic exercise helps sleep, but not always in the way we expect it to.

Light Therapy Can Help Treat Depression Year-Round

A new study reports that bright light therapy can help treat both seasonal and nonseasonal depression.

Sleeping In

Having a hard time getting your Teen up in the mornings? Read on, and get some tips on how to wake your cranky teen.

A Curious Case of Depression

A young adult male comes in reporting weight loss, fatigue, shortness of breath, difficulty concentrating, and depression so severe he's requesting "shock therapy." Where does one begin with such difficult cases?

10 Signs of Seasonal Depression (and 6 Ways to Fight It)

By Guy Winch Ph.D. on October 26, 2015 The Squeaky Wheel
When the days get shorter, the sun shines lower in the sky and the weather gets colder people often experience a drop in mood. Sometimes the drop is really big. Here's what you need to know:

Running On Empty?

When you find yourself feeling exhausted, you are in a state of deprivation, temporarily unable to replenish yourself. This means that the natural balance of give and take, which characterizes healthy living, is disturbed. The question is how to open yourself up again and, quite literally, change your mind.

Everything New Under the Sun

By Robert J King Ph.D. on October 09, 2015 Hive Mind
Time, identity, and immortality

Circadian Rhythm, Light and PTSD

By Leslie E. Korn Ph.D. on September 26, 2015 Rhythms of Recovery
PTSD, chronic pain (fibromyalgia), and sleep problems are all characterized by circadian rhythm imbalance. In order to understand more fully the disruption of rhythm and time perception caused by trauma, it is useful to explore the role of circadian rhythm, light, and the pineal gland.

Five Weird Facts About the Brain You Didn't Know

Discover shock and awe inside your own skull

Colors of Light and Life

What color is the light you're using to read this? Your answer matters. A lot.

When Is the Best Time to Give Birth?

By Robert D. Martin Ph.D. on September 14, 2015 How We Do It
Medical intervention in human birth is now so widespread in industrialized countries that deliveries are seldom spontaneous. Yet with no intervention there is clear persistence of a general mammalian 24-hour biorhythm in birth hour. Is this just a carryover from ancestors that gave birth during their inactive period, or is that basic rhythm still biologically important?

How to Balance Rhythms to Enhance Trauma Treatment

The major rhythmic disruption in PTSD and complex trauma is circadian rhythm; the 24 hr. sleep/wake cycle that follows the dark/light cycle of the sun’s rising and setting.

Whether to Wake Up or Snooze, and Why It Matters So Much

By Garth Sundem on August 18, 2015 Brain Trust
To snooze or not to snooze? The answer can determine whether you start the day with energy or insight.

Complicated Grief and the Inner Clock

By Michael Terman Ph.D. on August 11, 2015 Chronotherapy
For some bereaved individuals, grief turns from an emotion into an illness that can last months or years—and causes neurological changes that can be detected on an MRI. Find out more about complicated grief and the effects it can have on your sleep and circadian rhythms.

Be Creative When You're Sleepy

By Temma Ehrenfeld on August 05, 2015 Open Gently
Your creative times may be when you're a little groggy or drify.

Helicopter Parenting Isn’t Killing Millennials, but This Is

Doing this could save your kid's sanity (and maybe even his life).

Changing Clocks Causes Cancer?

Time rules life. Does disrupting inner body clocks cause cancer?

Everyday Access to Nature Promotes Well-Being As We Age

A new study reports that spending time in natural environments promotes healthy aging and overall well-being.

The Secret Life of Melatonin

Melatonin is a commonly used over the counter sleep aid, but this hormone's effect on fertility and puberty are powerful and not fully understood in humans. Caution should be exercised before any chronic use or using melatonin in kids.

How Does Your Circadian Clock Keep Track of the Seasons?

Until now, the specific neurobiology of how our circadian clocks keep track of the seasons has been a mystery. Recently, researchers identified how circadian rhythms synchronize with the seasons. These findings could lead to new treatments for Seasonal Affective Disorder (SAD) and insomnia.

The Best Defense Against Jet Lag? Ask the NBA

NBA teams may be getting better at mitigating players' jet lag.

Sleepless in the Summer

How to improve your sleep when the mercury rises

How Do Sleeplessness and Insomnia Sabotage Decision Making?

New research reveals how sleeplessness can thwart your ability to make astute decisions.

The Shot Clock and the Body Clock

By Alex Korb Ph.D. on March 27, 2015 PreFrontal Nudity
During March Madness most people overlook important aspects of neuroscience that contribute to peak athletic performance.

The House of Cards Characters Have Terrible Sleep Hygiene

By Jordan Gaines Lewis on March 06, 2015 Brain Babble
If Frank Underwood has trouble sleeping, it's not because of his conscience. Here's why the House of Cards characters have terrible sleep hygiene.

Why Do We Dream?

By Michael J Breus Ph.D. on February 13, 2015 Sleep Newzzz
Many scientists studying sleep and dreams believe that dreaming does have a purpose.

Our Dreaming World

By Michael J Breus Ph.D. on January 02, 2015 Sleep Newzzz
Despite sustained scientific exploration and attention—and no shortage of theories—we still don’t know the answer to the most fundamental question: Why do we dream?

When Our Bodies Lose Track of the Time

By John Cline Ph.D. on December 30, 2014 Sleepless in America
Internal circadian rhythms stay synchronized with external clock time because environmental factors such as light and meals align the rhythm with the external clock. If these cues are unavailable the circadian rhythm will steadily shift over time. For totally blind individuals this can result in problems such as insomnia and daytime sleepiness.

Sleep, as We Get Older

By John Cline Ph.D. on December 29, 2014 Sleepless in America
With advancing age there are changes in sleep pattern, sleep quantity and sleep quality. Sleep remains important for good health throughout our lives and understanding how these changes affect the sleep of older individuals can help people to maximize the quality and quantity of their sleep and thus their health.