Arch Intern Med. 2006 ;166:1709-15.
Peppard PE, Szklo-Coxe M et al.
BACKGROUND: Sleep-related breathing disorder (SRBD, also known as sleep apnoea) and depression have each been independently associated with substantial morbidity, impairment and disability. The development of clinical strategies for screening and managing depression in patients with SRBD requires elucidation of the association between the two conditions. This population-based epidemiological study assesses SRBD as a predictor of depression.
METHODS: Men (788) and women (620) randomly selected from a working population were evaluated for SRBD by in-laboratory polysomnography (a special sleep study to detect breathing abnormalities during sleep) and for depression by the Zung depression scale. Results of multiple studies, performed at 4-year intervals, were available for most participants. Sleep-related breathing disorder was characterized by the apnea-hypopnea index (AHI; events per hour). The categories were: AHI = 0 meant no SRBD; AHI between 0 and 5 meant minimal SRBD; 5 to15 inclusive, mild SRBD; and AHI greater than or equal to 15, moderate or worse SRBD. Depression was defined as a score of 50 or higher on the Zung scale or use of antidepressants.
RESULTS: In purely longitudinal models, an increase of 1 SRBD category (eg, from minimal to mild SRBD) was associated with a 1.8-fold increased odds for development of depression. In adjusted models combining longitudinal and cross-sectional associations, compared with participants with no SRBD, the odds for development of depression were increased by 1.6-fold in participants with minimal SRBD, by 2.0-fold in participants with mild SRBD, and by 2.6-fold in those with moderate or worse SRBD.
CONCLUSION: The authors suggest that the longitudinal findings of an association between SRBD and depression, which increases with severity, provide evidence consistent with a causal link between these conditions and should heighten clinical suspicion of depression in patients with SRBD.
Given the seriousness of sleep apnoea (SRBD) and its other associated conditions such as high blood pressure and risk of heart attacks, all HWC patients are screened for SRBD or sleep apnoea during the medical examination.
