May 1, 2016

Sleep apnoea and depression

A good night’s sleep can benefit our health in a number of ways including improving our concentration, alertness, memory and physical performance. Sleep reduces stress, strengthens the immune system and helps our bodies to heal. It is not only important that we get the right amount of sleep, which for the average adult is seven to nine hours per night, but we also need sufficient quality of sleep.

Unfortunately, sleep disorders, particularly Obstructive Sleep Apnoea (OSA), are common with up to 50 per cent of adult males and 20 per cent of adult females affected1. However, the majority of people do not realise they have a sleep disorder which could be affecting their health.

OSA is a potentially serious disorder because breathing repeatedly starts and stops during sleep. It can occur when the muscles in the throat relax and block the airway during sleep. Common symptoms of sleep apnoea include snoring, restless sleep, choking or gasping sensations, as well as periods of complete stoppage (apnoea) or partial reduction (hypopnea) of air flow, for at least 10 seconds. These breathing pauses may occur from 10 to 100 times an hour, depending on the severity of the condition. Daytime symptoms include feeling sleepy, tired or fatigued, as well as poor attention and concentration.

Depression affects around 5 per cent of men at any one time in Australia. Depression occurs much more frequently in sleep apnoea patients, with estimates as high as 20 to 40 per cent reported from studies in patients referred to sleep clinics. These patients are likely to be different from people with undiagnosed sleep apnoea in the community. Our study, conducted through the University of Adelaide, in a large community-based sample of Australian men2, confirms a strong relationship between sleep apnoea and depression even after adjustment for a number of other potential risk factors. In our study 1,875 men aged between 35 and 83 were assessed for depression and other health, lifestyle and demographic risk factors. A random sample of 857 men without a previous sleep apnoea diagnosis then underwent an overnight sleep study in their own homes.

We found that OSA and excessive daytime sleepiness were both significantly associated with an increased risk of depression in men. There are a few plausible explanations for why sleep apnoea and depression may coexist with each other e.g. the two disorders have overlapping symptoms and share common risk factors. It is important that clinicians recognise that individuals with severe sleep apnoea have a greater likelihood of having depression regardless of whether excessive daytime sleepiness is also present. However, if excessive daytime sleepiness is present there is a greater likelihood of depression, even in men with mild to moderate sleep apnoea and this needs recognition. Our findings suggest that individuals presenting to health practitioners with depressive symptoms should be assessed for sleep apnoea. Treating sleep apnoea may be of benefit to depressive symptoms3.

References

  1. Heinzer R, Vat S, Marques-Vidal P, et al. Prevalence of sleep-disordered breathing in the general population: the HypnoLaus study. Lancet Respir Med 2015; l3: 310-8.
  2. Grant JF, Martin SA, Taylor AW, et al. Cohort profile: The Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) Study. Int J Epidemiol 2014; 43: 1040-53.
  3. Chai-Coetzer CL, Antic NA, McEvoy RD. Identifying and managing sleep disorders in primary care. Lancet Respir
    Med 2015; 3: 337-9.