How long will we sleep on obstructive sleep apnoea in schizophrenia?

People with Schizophrenia often sleep 9–12 hours each night, and during the day, many are sleepy and fatigued. Complaints of insomnia, poor-quality sleep and restless legs are also common. So the question is, if 50% of their life is spent sleeping, why are mental health clinicians not investigating sleep symptoms and accurately diagnosing and facilitating access to freely available and evidence-based interventions?

The recently published Schizophrenia Clinical Practice Guidelines (CPG) (Galletly et al. 2016) appropriately emphasised physical healthcare and demonstrated the Royal Australian and New Zealand College of Psychiatrists’ (RANZCP) commitment to providing clinicians with up-to-the-minute research by including a section on obstructive sleep apnoea (OSA). Recent reviews (Kalucy et al. 2013; Myles et al., 2016) highlight the potentially high prevalence of severe OSA and emphasise the need for targeted research in this area. It is likely that approximately 30% of people with schizophrenia have undiagnosed severe OSA. Treatment of previously undiagnosed OSA could lead to improvements in the main drivers of morbidity and mortality in this population: quality of life, cardiometabolic health and cognition. Our review (Myles et al. 2016) suggests a practical approach to screening and advises about appropriate diagnostic and management pathways.

Preventing the metabolic side effects of antipsychotics is front and centre in the Schizophrenia CPG. Olanzapine is now recommended as a second-line agent in first-episode psychosis due to its poor metabolic profile. Additionally, the CPG includes recommendations for monitoring of cardiometabolic risk factors and evidence-based strategies for managing physical health complaints. This is in response to a growing body of evidence highlighting that physical health inequality drives a 15- to 17-year reduction in life expectancy (Galletly et al., 2012) predominantly due to obesity, type 2 diabetes and cardiovascular disease. OSA contributes to cardiometabolic risk, and it requires further attention to improve physical health outcomes in this population. Untreated OSA increases oxidative stress and sympathetic activation which exacerbate hypertension, insulin resistance, heart failure and atrial fibrillation. OSA is associated with increased cardiovascular morbidity and healthcare costs. Importantly, OSA is a treatable disease, with continuous positive airway pressure (CPAP) being the gold standard treatment, offering a means of synergistically improving multiple cardiovascular risk factors, physical health morbidity and quality of life. Excessive daytime sleepiness, fatigue and poor quality of life in this patient group are almost certainly multifactorial. Medications, sleep patterns, mood disturbance, illness factors and OSA are all potential contributors. Clinicians should identify and address all contributing factors, and the CPG guidelines encourage and facilitate this practice.

There is a widespread perception that people with schizophrenia are unable to tolerate a complicated sleep study and are unlikely to comply with or afford CPAP treatment. In contrast, data from our ongoing unpublished project investigating the prevalence of OSA and acceptability and effectiveness of treatments show that with proper community support, people with schizophrenia tolerate home sleep studies (100%), have high rates of OSA (about 45%) and most strikingly have rates of very severe untreated OSA three times that of the general population (about 30%). Importantly, the acceptance of treatment (CPAP), which is provided without cost, is comparable to the general population (about 75%).

Both home sleep study and CPAP treatments are accessible from established sleep services. Treatment for severe OSA with CPAP is subsidised through state health services for patients through public sleep services in most states of Australia.

OSA screening has previously been neglected from physical health guidelines, but we suggest that there is a compelling case for screening for and managing OSA in this group. OSA is more common in men, and specific risk factors identified in our systematic review of the schizophrenia literature (Myles et al. 2016) include neck circumference > 40 cm, body mass index (BMI) > 25, age > 50 and witnessed apnoea or loud snoring. Although no validated screening tools in the schizophrenia population exist, the OSA50 (Chai-Coetzer et al., 2011) has been validated in a primary care setting. An OSA50 score ⩾ 5 indicates that a sleep study is required. Given that snoring and pausing may go unnoticed due to the frequent lack of bed partner and medication induced daytime sedation, there should be a low threshold for testing in this population, particularly those who are overweight or obese. Treating OSA has positive cardiac (reduced arrhythmias) and vascular (improves blood pressure) outcomes, may reduce the burden of sleepiness, improve physical health outcomes and improve cognition.

OSA may be the neglected cardiometabolic risk factor and a missing link in the answer to rehabilitation. Diagnosis and treatment of OSA should not be withheld from people due to treatment nihilism and misconceptions about availability, acceptability and effectiveness of subsidised treatments.