After a bad night of sleep, do you feel groggy? Irritable? Maybe, in extreme cases, even depressed? It’s not uncommon for a night of poor sleep to affect mood, but can it really escalate to the point of depression? If so, perhaps a night full of apneas can worsen sleep to the point of depression. Therefore, a recent study sought to investigate whether untreated sleep apnea is linked with depression and whether sleep apnea treatment (CPAP) can alleviate these symptoms.
The first phase of the experiment assessed whether those with untreated sleep apnea have elevated levels of depression. Research participants underwent an overnight sleep study to assess the presence and severity of obstructive sleep apnea (OSA). Each participant also completed the Patient Health Questionnaire, which is a standard questionnaire for gauging symptoms of depression (example question: In the past 2 weeks, have you felt bad about yourself — or that you are a failure or have let yourself or your family down?). Depression scores were then correlated with OSA severity to see if a relationship between these two factors exists.
There was a significant relationship between the number of apneas and hypopneas per hour and depression scores, such that worse sleep apnea was linked with higher depression scores. The same relationship existed for body mass index (BMI), where a higher BMI was linked with higher depression.
The second phase of the experiment explored the possibility that depressive symptoms may be reduced after sleep apnea treatment. Before this could be done, CPAP compliance (i.e., how often the CPAP was used) had to be determined using the usage-monitoring chip inside the CPAP machine. Those who used their treatment for at least 5 hours per night were included in the analysis. The depression scores of these individuals, obtained before and after treatment, were compared.
As expected, the number of apneas and hypopneas per hour decreased significantly after CPAP treatment (47/hour vs. 7/hour). Amazingly, depression scales also decreased significantly after treatment. And finally, the amount of individuals with “depression,” as gauged by a score over 10 on the depression scale, reduced from 75% of the sample to 4% of the sample.
During the first phase of this study, there were cloudy results, such that depression was linked to both sleep apnea and BMI. Given that there is a strong link between BMI and sleep apnea, the relationship between sleep apnea and depression could have been confounded. However, CPAP treatment significantly reduced depression scores, while weight remained stable. These results show that untreated sleep apnea may exacerbate or even cause depression in some individuals. Therefore, for the sake of your mental health and happiness, stay treated!
Source: Edwards, C., Mukherjee, S., Simpson, L., Palmer, L. J., Almeida, O. P., & Hillman, D. R. (2015). Depressive Symptoms before and after Treatment of Obstructive Sleep Apnea in Men and Women. Journal of clinical sleep medicine: JCSM: official publication of the American Academy of Sleep Medicine.