Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

What are circadian rhythms?

The word ‘circadian’ comes from the Latin ‘circa’  meaning ‘around’ and ‘diēs’, meaning ‘day’. Our circadian rhythms are biological processes that follow a (roughly) 24-hour cycle.  Throughout the day our alertness levels will wax and wane, as will our temperature, blood-pressure, appetite and hormone production. These fluctuations are examples of circadian processes. The most obvious circadian process is the sleep-wake cycle.

Circadian rhythms and mental health

At any one time, 16 per cent of adults in the UK have a common mental disorder, while 1 per cent has a severe mental illness, such as schizophrenia or bipolar disorder. Mental disorders are estimated to become the biggest cause of disability by 2030. A recent study by the European Brain Council estimated the cost of brain disorders to Europe alone at €800 billion in 2010. A striking, long-recognised and diagnostic feature of mental illness is SCRD and poor health. Although clinically recognised, the precise nature, causes and effects of SCRD in mental illness are poorly defined, and its treatment invariably neglected.