Circadian Rhythms....

Circadian Rhythms

With the clocks going forward, we may feel some tiredness adjusting.

Circadian rhythms are physical, mental and behavioural changes that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism’s environment. They are found in most living things, including animals, plants and many tiny microbes. The study of circadian rhythms is called chronobiology. What are circadian rhythms?

There’s a section of our brain that synchronises our body to a 24-hour cycle and releases hormones to regulate regular bodily functions, like our appetite, energy levels, mood and sleep. These daily cycles for appetite, sleep, etc. are known as circadian rhythms and are really important to our physical and emotional well-being. They help us to keep a stable mood a

nd good physical health. Your body can usually tell when to prepare for certain events.

For example, when the sun comes up your body releases cortisol to give you energy so you can be active during the day, and when the sun goes down, you produce and release melatonin, a hormone that makes you sleepy. Sometimes these cycles get messed up and that can wreak all sorts of havoc on our physical and emotional health. When our circadian rhythms are disrupted and our bodies produce hormones at the wrong time of day, it can increase the chance of depression or make existing depression worse. For example, producing melatonin in the daytime can make us feel dull, unstable, irritable and moody.

Are circadian rhythms the same thing as our biological clock? No, but they are related. Our biological clock drives our circadian rhythms. What are biological clocks? The biological clocks that control circadian rhythms are groupings of interacting molecules in cells throughout the body. A “master clock” in the brain coordinates all the body clocks, so that they are in synch. What is the master clock? This controls your circadian rhythms and consists of a group of nerve cells in the brain called the suprachiasmatic nucleus, or SCN. The SCN contains about 20,000 nerve cells and is located in the hypothalamus, an area of the brain just above where the optic nerves from the eyes cross.

Do circadian rhythms have a genetic component? Yes. Researchers have already identified genes that direct circadian rhythms in people, fruit flies, mice, fungi and several other model organisms that have been used for studying genetics. Does the body make and keep its own circadian rhythms? Circadian rhythms are produced by natural factors within the body, but they are also affected by signals from the environment. Light is the main cue influencing circadian rhythms, turning on or turning off genes that control an organism’s internal clocks. How do circadian rhythms affect body function and health? Circadian rhythms can influence sleep-wake cycles, hormone release, body temperature and other important bodily functions. They have been linked to various sleep disorders, such as insomnia.

Abnormal circadian rhythms have also been associated with obesity, diabetes, depression, bipolar disorder and seasonal affective disorder. How are circadian rhythms related to sleep? Circadian rhythms are important in determining our sleep patterns. The body’s master clock, or SCN, controls the production of melatonin, a hormone that makes you sleepy. Since it is located just above the optic nerves, which relays information from the eyes to the brain, the SCN receives information about incoming light. When there is less light –like at night – the SCN tells the brain to make more melatonin so you get drowsy. Circadian rhythms and depression Your body regulates on a 24-hour cycle that can get messed up when you don’t either get enough light or too much light.

Find out about your circadian rhythm and what happens when it is disrupted, including its link to several mental health disorders. Get tips on how to overcome circadian disruption. There are a number of signs that this might be a problem, such as a bad sleeping pattern and feeling tired and depressed in winter when you don’t get much light.

So what causes circadian systems to get messed up?

• Lack of sleep, stress and trauma

• Going to bed, waking up at strange hours, shift work

• Genetic factors

• Lack of light.

Signs and symptoms of circadian disruption When our circadian rhythms have been disrupted, it can have a range of impacts on our physical and mental health, such as: Not being able to feel alert Becoming easily agitated feeling slow Feeling run down and exhausted Feeling grumpy and irritable Experiencing symptoms of depression. Other disorders impacted by circadian rhythms: Seasonal Affective Disorder Seasonal Affective Disorder (SAD) affects people in the winter months when it is darker and colder, particularly in areas of the world that don’t receive much sunlight. When days become shorter and we don’t receive enough light, our brains can miss the cues to produce the right hormones at the right times. This can mean we might be sleepier or more energetic at the wrong time of day. Bipolar disorder Bipolar disorder is different to other types of depression in that it is marked by episodes of unusually elevated mood or mania. These episodes can last for hours, days or even months. In many cases of bipolar disorder, depressive and manic episodes are seasonal. What to do about circadian disruption? There are a range of things people do to get their circadian schedule back in working order. The first step is to recognise and correct bad habits that could lead to problems. You can make corrections such as:

• Not taking naps during the day.

• Allow yourself time to wind down at the end of the day.

• Checking out some ways to relax.

• Getting exposure to sunlight in the mornings.

• Getting into regular sleeping routine – try to go to bed and wake up at the same times each day and night.

• Eating and exercising regularly. If this isn’t working… Sometimes this isn’t quite enough and a doctor may need to help you with different strategies to kick your cycle back into the right pattern.

These include:

• Light therapy – exposure to bright or blue light during the daytime can help your cycle realign

• Medication – your doctor will be able to work with you to figure out an approach that suits you and your lifestyle.

What can I do now? Get tips on how to establish a good sleeping routine. Try and get up and go to bed at the same time each day, allowing for 8-9 hours sleep each night. Get outside and enjoy the morning sunshine.