Many veterans struggle with mental illnesses like depression and PTSD, and many veterans suffer from sleep apnea. There is a well-known correlation between mental illnesses and obstructive sleep apnea (OSA). Studies show us that while 4% of American men suffer from sleep apnea, the percentage of OSA sufferers with depression (22%), anxiety disorders (17%), and PTSD (11%) is much higher than in the general population. Another study of PTSD sufferers found sleep-disordered breathing in 40 out of 44 patients, with half of the patients meeting the criteria for obstructive sleep apnea. Many veterans are denied service-connection for their apnea, but have service connected mental illness, or vice versa. It is therefore important that we understand exactly how the two are related. Does OSA worsen mental illness? Does mental illness worsen sleep apnea?
The answer is both. The symptoms of mental illness can make sleep apnea worse, and sleep apnea can contribute to mental illness.
First, let’s take a look at how mental illness can affect sleep apnea. PTSD sufferers have a much higher number of sleep disturbances and sleep fragmentation than those without PTSD. The truth is, sleep is one of the first victims of most serious mental illness, and sleep difficulty, sleep deprivation, and frequent awakenings are seen in depression, anxiety, and PTSD alike.
Sleep deprived patients have been shown to have increased frequency and length of apneic events, similar to the effects of alcohol. Sleep-deprivation appears to impair the muscle that controls your tongue, called the genioglossus. Impairment of this muscle is the main cause of obstructive sleep apnea. When sleep-deprived, when we finally DO sleep, we have much shorter periods of “slow-wave sleep.” A decrease in slow-wave sleep has also been implicated in worsening OSA. Regardless of sleep deprivation, patients with PTSD have been shown to have shorter slow-wave sleep, and more frequent awakenings during the first half of the night.
Anxiety has also been shown to contribute to sleep-disordered breathing. One study of Japanese male workers found that sleep-disordered breathing increases proportionally to occupational stress. If on-the-job stress affects your sleep-breathing, it seems more likely than not that a veteran with PTSD-related anxiety or an anxiety disorder would also have some problems.
Many anti-anxiety drugs that are commonly prescribed to veterans have been shown to greatly increase the severity of sleep apnea. In fact, some studies have shown that benzodiazepines can actually induce sleep apnea in snorers who previously did not suffer from apnea.
Sleep apnea can also make mental illnesses worse, and some doctors actually believe that those with apnea are much more likely to develop PTSD than those without apnea. The reasons are complex, but they involve increased levels of stress hormones, as well as the way we process memories. PTSD is primarily a problem with the way that memories are consolidated and processed in the brain. Sleeping is when we consolidate these memories. So it may be that sleep apnea hinders memory consolidation, and could potentially lead to PTSD after exposure to a trauma. Sleeping is extremely important for mood as well, and the severe way that apnea can affect sleep cycles can affect depression and anxiety.