Sleep apnoea and depression often travel together

Mood disorders such as major depressive disorder and bipolar disorder, and obstructive sleep apnoea, are all common conditions with serious consequences for individuals and public health. Research increasingly suggests they share risk factors and can influence one another — each worsening the other's symptoms and treatment response. Yet despite growing attention, there has been no clear picture of just how often these conditions co-occur, or what factors drive the overlap. Establishing the true scale of comorbidity matters because it determines whether clinicians treating one condition should be actively looking for the other.

The researchers systematically reviewed EMBASE, Ovid MEDLINE, Global Health and APA PsycINFO for studies of comorbid obstructive sleep apnoea and mood disorders published between 1 January 2013 and 25 July 2025. Out of 6221 screened studies, 23 articles met eligibility criteria. These yielded 2,380,986 OSA patients, among whom 446,495 had comorbid mood disorders, and 5724 mood disorder patients, among whom 450 had comorbid OSA. Meta-analyses applied random-effects models, with assessments of heterogeneity and publication bias, plus subgroup and meta-regression analyses examining demographic, clinical and study-quality variables.

All meta-analyses demonstrated a significant prevalence of comorbidity between obstructive sleep apnoea and mood disorders, accompanied by substantial heterogeneity across studies. Within the mood disorder totals, major depressive disorder dominated the OSA cohorts (446,290 of the comorbid cases) while bipolar disorder was far rarer (205 cases). Meta-regression identified two significant moderators of OSA prevalence: mean age (β = 0.18, 95% CI 0.03-0.33) and mean body mass index (β = -0.18, 95% CI -0.32 to -0.04). In other words, the demographic makeup of a study population meaningfully shifted how much overlap was observed.

This analysis consolidates a decade of research pointing to a genuine, sizeable overlap between disordered breathing in sleep and disorders of mood, and it quantifies that overlap across millions of patients for the first time at this scale. The substantial heterogeneity and observational nature of the underlying studies mean the direction of influence remains unresolved — whether apnoea drives low mood, mood disorders worsen sleep breathing, or shared factors underpin both. The strikingly small bipolar disorder numbers also leave that side of the picture far less certain than the depression findings. The authors conclude the results argue for systematic screening and tailored approaches in both clinical practice and research.

If you or someone close to you lives with either persistent low mood or diagnosed sleep apnoea, this is a reason to be aware that the two conditions frequently coexist and can feed each other's symptoms. It is a case for curiosity rather than alarm: comorbidity data cannot say that one condition causes the other, only that finding one should raise the question of the other. The moderating roles of age and body-mass index also underline that risk profiles differ between people. Anyone concerned about symptoms of either condition would discuss assessment with a clinician — the study's core message is that these conversations should happen more systematically.