Major Depression (Major Depressive Disorder) is one of the most common mental health disorders, but how often are we working up sleep as a cause or contributing factor? A large epidemiologic study by Ford DE et al in 1989 found that at least 40% of patients with either insomnia or hypersomnia had a concurrent psychiatric disorder, such as depression. Along the same lines, more complicated sleep disorders such as obstructive sleep apnea and restless leg syndrome are more likely to be found in the population of depressed patients compared to the general population.
Evidence suggests a bidirectional relationship between common sleep disorders and depression, meaning that one may elevate the risk for the other. Although we do not understand the exact mechanisms, sleep seems to ‘clean the brain’ at night (Xie et al. 2013); depression can lead to worsening cognitive function. It is hard to deny that improving sleep is important for brain health and for alleviating depressive symptoms! In fact sleep studies demonstrated that after patients were treated for depression, there were positive brain changes on polysomnography and electroencephalogy. In such studies, slow wave sleep (what we will term "good" sleep) is increased and REM sleep (what we will term "not-as-good" sleep) is decreased.
Interestingly, antidepressants have been linked to decreased total REM sleep. Although some antidepressants play a positive role in sleep disorders, it is important to talk to your psychiatrist about the positive and negative effects of your antidepressant on any given sleep disorder. Some antidepressants may be more useful for certain types of sleep disorders but vary largely based on the type of sleep disorder. For example, extended release bupropion may worsen insomnia disorder but help regimented patients overcome hypersomnia (sleeping too much) that accompanies circadian rhythm dysregulation. Bupropion may be more neutral and even beneficial for restless legs syndrome, whereas other antidepressants can worsen restless legs syndrome.
As more evidence becomes available regarding the importance of sleep, it is becoming more important for patients and physicians to become educated on sleep disorders. Because sleep disorders and depressive disorders both produce similar symptoms of excessive daytime sleepiness, fatigue, poor concentration, weight gain and irritability, among many others, we must not overlook sleep disorders before coming to the conclusion that depression is the only cause of such common symptoms.
An important note on obstructive sleep apnea: Although there many different types of sleep disorders, obstructive sleep apnea has a high prevalence in the general population and especially in depressed patients. It is worth noting that this sleep apnea frequently goes untreated and can be harmful to the brain over a long period of time. This disorder causes hypoxic episodes, meaning that your body and brain do not get enough oxygen for short periods of time. This is why patients with sleep apnea frequently have headaches in the morning. If you have depressive symptoms such as those mentioned in the paragraph above in addition to snoring, along with certain risk factors such as obesity, diabetes, hypertension and heart disease, you should consider talking with your doctor about a referral to a sleep physician or sleep study. In fact, you can find a number of sleep apnea screeners online such as http://www.stopbang.ca/osa/screening.php, but please remember that it is not diagnostic and only your physician can rule sleep apnea in or out.
If you suffer from continued depression despite following interventions from your sleep and/or other physician(s), give us a call at (561) 531-7818 or email us at firstname.lastname@example.org to learn about how ketamine can help with depression. Of note, ketamine is not a treatment for primary sleep disorders.