How does sleep affect health?

Getting a good night’s sleep is essential for health and wellbeing, but almost four in 10 Australians are regularly not getting enough quality sleep.
 
Given these findings, it is little surprise the recent Parliamentary inquiry into sleep outcomes has called for a national campaign to help Australians sleep better – equating to better quality of life.
 
A new Sleep Awareness Week campaign focuses on the benefits of sleep for optimal cognitive functioning, from infancy to old age.
 
Darren Mansfield, Clinical Associate Professor at Monash University and Director at the Epworth Sleep Centre, told newsGP that there is an established link between sleep disorders and a person’s mood.
 
‘Just about all of the sleep disorders can be linked in some way with mood symptoms. So if we think about improving the mental health of our community, sleep is a really good place to start,’ he said.
 
‘Sleep disorders and mood disorders are so interlinked. Tiredness and sleepiness flattens the mood and, in reverse, people with flat moods tend to be tired and sleepy, so we think it’s a bi-directional relationship.’
 
Associate Professor Mansfield said the most common issue is loss of sleep itself, or ‘insufficient opportunity’ for sleep, and believes that people would sleep well if they gave themselves the best chance to do so.
 
So how much sleep do we really need? That depends, according to Associate Professor Mansfield.
 
‘The recommendations are for an average of nine hours sleep for adolescents [up to about 18 years of age], then around eight hours in adulthood,’ he said.
 
‘But these are guides only and there are a lot of individual variations ... some people need more than that, and some can get by on a bit less.
 
‘We’re always encouraging people to ensure they give themselves optimal opportunity.’
 
This opportunity begins with establishing good routines and sleep hygiene, which Associate Professor Mansfield believes can be encouraged by GPs, who are becoming increasingly involved in assessing and managing sleep issues.
 
‘We want GPs and other healthcare professionals to be alert in recognising sleep disorders, as they are common,’ he said.
 
‘GPs can ensure they are doing all the right things from a sleep hygiene perspective, things that people can do to optimise their sleep patterns.’
 
Sleep hygiene recommendations include having regular bed and wake-up times (including weekends), limiting caffeine and alcohol intake, regular exercise (preferably not too close to sleep onset), and to avoid napping too much in the day.
 
Associate Professor Mansfield also highlights the benefits of a referral for cognitive behavioural therapy for sleep disorders such as insomnia, which he believes is mood-related.
 
‘Insufficient sleep opportunity is different to insomnia, where there is the opportunity to sleep, but you just can’t,’ he said.
 
Other common sleep issues have an effect on mood, such as sleep apnoea and body clock – or circadian – disorders.
 
‘Body-clock disorders that are connected to mood disorders – depression, in particular, and anxiety,’ Associate Professor Mansfield said.
 
‘The natural tendency would be to fall asleep later with a preference then to sleep in much later, which obviously may not fit in well with the way the majority of the world works.
 
‘So these people may find themselves not managing to fit in very well, or curtailing a lot of sleep in order to get up early.’
 
Body-clock disorders are especially common in adolescents and adults who are shift workers, according to Associate Professor Mansfield.
 
‘There is a real issue in [adolescents] in particular, because they are very susceptible to insufficient sleep,’ he said.
 
‘If they stay up late before school the next day ... or there might be technology [screen time] as a factor, or sports training on at night, then these kids are really getting insufficient sleep.’
 
BMJ Open has launched a pilot evaluation of a smartphone app for adolescent sleep issues, and the Parliamentary inquiry into sleep outcomes also recommended that children and adolescents be one of the main target groups for the national sleep health campaign.

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