Cognition in schizophrenia improves with treatment of severe obstructive sleep apnoea: A pilot study

Abstract

Previous studies have shown that people with schizophrenia have high rates of Obstructive Sleep Apnoea (OSA). Despite this, intervention studies to treat OSA in this population have not been undertaken. The ASSET (Assessing Sleep in Schizophrenia and Evaluating Treatment) pilot study investigated Continuous Positive Airway Pressure (CPAP) treatment of severe OSA in participants recruited from a clozapine clinic in Adelaide. Participants with severe untreated OSA (Apnoea-Hypopnoea Index (AHI) > 30), were provided with CPAP treatment, and assessed at baseline and six months across the following domains: physical health, quality of sleep, sleepiness, cognition, psychiatric symptoms and CPAP adherence. Six of the eight ASSET participants with severe OSA accepted CPAP. At baseline, half of the cohort had hypertension, all were obese with a mean BMI of 45, and they scored on average 1.47 standard deviations below the normal population in cognitive testing. The mean AHI was 76.8 and sleep architecture was markedly impaired with mean rapid eye movement (REM) sleep 4.1% and mean slow wave sleep (SWS) 4.8%. After six months of treatment there were improvements in cognition (BACS Z score improved by an average of 0.59) and weight loss (mean weight loss 7.3 ± 9 kg). Half of the participants no longer had hypertension and sleep architecture improved with mean REM sleep 31.4% of the night and mean SWS 24% of the night. Our data suggests CPAP may offer novel benefits to address cognitive impairment and sleep disturbance in people with schizophrenia.

Pilot cohort study of obstructive sleep apnoea in community-dwelling people with schizophrenia

“…Thirdly, our data are observational and does not determine whether treatment of OSA co-morbid with schizophrenia improves cognitive measures, psychopathological outcomes, quality of life outcomes or cardiovascular risk factors. However, in an extension of this pilot study, we monitored the response to CPAP and found CPAP improved obesity and cognition when used in people with schizophrenia and severe OSA (published elsewhere) (Myles et al, 2019). Given the high prevalence of OSA in our pilot study and because CPAP treatment modifies these outcomes in general populations, further intervention studies are required to determine whether OSA treatment has any role in improving outcomes in this population.…”

Medication of comorbidities in females with sleep-disordered breathing during long-term CPAP therapy

“…Symptoms of OSAS can resemble those of mental disorders and some medications used for severe mental disorders can exacerbate the symptoms of OSAS [31]. CPAP therapy for OSAS has been shown to improve cognitive impairment of schizophrenia patients [32], but has also resulted in manic symptoms in patients with bipolar disorder [33]. However, in one review, prevalence of OSAS was not increased in patients with schizophrenia, bipolar disorder or severe depression [34].…”

Don't let sleeping men lie

“…Fatigue and reduced concentration may result in lower productivity and increased workplace injuries. There is also increasing evidence that OSA accelerates the progression of Alzheimer's disease, and effective treatment of OSA may delay the onset of cognitive impairment and prevent psychiatric disorders 22–24 . There is a significant relationship between depression and OSA.…”

“…These conditions have shared risk factors, the symptoms overlap and there is bidirectional causality 25 . The prevalence and severity of OSA are increased in men with schizophrenia, 26 and treatment has been shown to be acceptable and beneficial 24 …”