Circadian Rhythm Sleep Disorders

Circadian Rhythm Sleep Disorders are a family of sleep disorders affecting the timing of sleep, characterised by an inability to sleep and/or wake at normal or appropriate times due to the dictates of the individual’s biological or circadian clock.

As a result, sleep is attempted (or actually occurs) at an abnormal time in the individual’s circadian cycle.

People with circadian rhythm sleep disorders are therefore unable to sleep and wake at the times required for normal work, school, and social needs, which can severely  impact their quality of life.

Circadian rhythm sleep disorders arise due to phase shifts in individual circadian clocks.

Circadian rhythm sleep disorders arise due to phase shifts in individual circadian clocks.

The spectrum of CRSD includes:

  • Advanced Sleep Phase
  • Delayed Sleep Phase
  • Irregular Sleep-Wake Pattern

Delayed sleep phase syndrome is when people cannot fall asleep till late often the early morning and then cannot wake up till late, missing work or school. We are involved in a national NHMRC funded study investigating the role of melatonin in such patients and work in our inter-disciplinary clinic managing this common problem.

As well it is well known that some patients with severe mental illness such as schizophrenia have very disorganised sleep time and often sleep during the day. In collaboration with other Sydney Local Health District researchers, we hope to understand the circadian rhythm and other sleep disorders (such as sleep apnea) impacting on patients with severe mental illness.