January 2, 2026, 11:56 am | Read time: 6 minutes

Study on the Impact of OSAS Sleep Disorder on Mental Health

There is simple snoring caused by narrowed airways, and then there is sleep apnea. This is a serious and often undetected sleep disorder where the upper airways repeatedly block during sleep. This leads to characteristic breathing interruptions, which bed partners of those affected are likely to notice at night. Sleep apnea sufferers themselves usually only become aware of the consequences of their interrupted sleep the next day—in the form of daytime fatigue.

FITBOOK delves deeper into the symptoms, causes, and possible secondary conditions of the sleep disorder in this article. Many of these affect physical health. The repeated breathing interruptions during sleep lead to oxygen deficiency, stress reactions, and inflammation. The latter is a significant burden on the heart, blood vessels, metabolism, and other organs. However, sleep apnea also seems to affect mental health. Previous studies have already shown links between untreated sleep apnea and specifically the mental illness depression.¹ Large, representative long-term studies that reliably demonstrate these connections have been lacking until now. A research team from Ottawa attempted to close this research gap through the secondary analysis of a comprehensive long-term study.²

Study Details

The study was based on data from more than 30,000 participants in the large, nationwide long-term study “Canadian Longitudinal Study on Aging” (CLSA).³ The study examines how health, psychological, social, and economic factors develop over the course of aging. The CLSA has been running since 2011. It includes adults aged 45 to 85 who had no cognitive impairments at the start of the study. The goal of the cohort study is to observe changes over several years.

In this work, the scientists wanted to find out whether the sleep disorder OSAS in people aged 45 and older is associated with a higher likelihood of developing mental illnesses. Additionally, they aimed to determine which individual factors in people with a high risk of sleep apnea promote the development of mental illnesses. The focus of the study was on three central diagnoses in the field of mental illnesses. These were: anxiety disorders, mood disorders (such as bipolar disorder), and clinical depression.

Methods

The researchers evaluated data from two survey points. The first data collection took place between 2011 and 2015 and included 30,097 subjects. A follow-up survey occurred from 2015 to 2018, with 27,765 participants. The data were mostly collected through personal interviews with trained study personnel. Participants answered questions about their health, sleep, and mental well-being. Additionally, the researchers conducted simple medical examinations, such as blood pressure measurements and recording height and weight.

Assessment of OSAS Risk and Mental Health

The risk for OSA was determined using the validated STOP questionnaire. A high risk was present if at least two of the four criteria (snoring, daytime fatigue, observed breathing interruptions, or high blood pressure) were met. Additionally, a separate question was used to determine whether breathing interruptions during sleep had ever been observed. The main psychological outcome was a composite indicator of poor mental health. It was considered fulfilled if at least one of the following criteria was present: elevated scores in established questionnaires on depression or psychological distress, a medically diagnosed mental illness, or the use of antidepressants.

Also interesting: From Parkinson’s to Cirrhosis! 172 Diseases Linked to Poor Sleep

Study Results

The results show a clear connection between a high risk for obstructive sleep apnea and mental illnesses. At the start of the study, individuals with OSAS risk had a 39 percent higher likelihood of meeting the criteria for poor mental health. Even at the follow-up several years later, the risk remained similarly high. Participants without mental illness at the start of the study developed new mental problems 20 percent more frequently if they had a high OSAS risk. Considering both time points together, the likelihood of mental illnesses in OSA risk individuals was 44 percent higher. Even the sole occurrence of observed breathing interruptions during sleep was associated with a significantly increased risk for depression, anxiety disorders, and mood swings. Overall, about one-third of participants met the criteria for poor mental health at the start of the study; at follow-up, it was around 32 percent.

More on the topic

Research How High Temperatures at Night Affect Sleep Apnea

Many Affected Individuals Regularly Playing a Conch Shell Trumpet Can Apparently Alleviate Symptoms of Sleep Apnea

Possible Significance of the Study

The researchers consider an increased OSAS risk as an independent risk factor for mental illnesses in older age. This is particularly relevant because the sleep disorder is treatable. In many cases, affected individuals can achieve relief through weight reduction, more exercise in daily life, or a change in sleep position. Additionally, there is a very effective treatment method using so-called CPAP masks. These deliver a continuous airflow under slight pressure into the airways, keeping breathing free during sleep. However, according to the study authors, up to 90 percent of cases remain undetected and therefore untreated.

The study results suggest that early assessment of OSAS risk, for example, using the STOP questionnaire, could help prevent the development of psychological secondary conditions. Targeted therapies, such as the use of CPAP masks, might also alleviate existing psychological symptoms or prevent their development.

Limitations

However, some limitations should be noted. First, the pool of subjects was not very diverse. The study participants were predominantly white, lived in cities, and were educated. This limits the applicability of the results to other population groups. Additionally, both the OSAS risk and mental illnesses were assessed through self-reports. Medical diagnoses and objective sleep measurements that could confirm the presence of the sleep disorder and its effects on the psyche are lacking. While the STOP questionnaire reliably identifies most cases, its accuracy regarding actual OSAS cases is only moderate, the authors admit. Therefore, an overestimation of the risk is possible. Furthermore, the observed connection cannot be interpreted as a cause-and-effect relationship. In other words, it is equally possible that mental illnesses themselves increase the risk for OSA. Another significant limitation is that no information was available on any OSAS treatments. Despite the overall robust evidence from the study, it remains unclear whether treating the sleep disorder could reduce the risks to mental health.