Several recent studies have shown a very high incidence of sleep apnea in anxiety disorders. These include disorders such as Post Traumatic Stress Disorder (PTSD), Generalized Anxiety Disorder and Panic Disorder as well as Obsessive Compulsive Disorder. Sleep apnea has been noted most often in PTSD, both in studies on returning veterans as well as in woman who have suffered sexual trauma.
Until recently, it remained hard to explain why people with anxiety disorders had coexisting sleep apnea. The percentages were too high to be coincidental and how these disorders could trigger sleep apnea made little sense. In addition, if the sleep apnea were coincidental or secondary, why is it that treating the sleep disorder results in significant improvement in the anxiety disorder?
The answer may lie in the Limbic System. This is the part of the brain that regulates autonomic and endocrine function, particularly in response to emotional stimuli and physical threats. The limbic system contains the amygdala, which receives the information. This is then passed on to the hippocampus, which compares these stimuli to prior memories. If perceived as foreign and a threat, the fight or flight part of our nervous system, the sympathetic nervous system, is activated. In addition, stress hormones are released.
We now believe that many of these people have preexisting sleep apnea. In fact, it may be that sleep apnea sets them up for the anxiety disorders. The theory is that the presence of increased levels of stress hormones and an activated sympathetic nervous system may impair the ability to deal with life’s stresses, and in the case of PTSD, severe psychological trauma. In fact, it is during sleep, especially REM sleep, when much of emotional reconciliation with the day’s events occur. If our sleep is severely fragmented by sleep apnea, our ability to accomplish this is hindered. This also might explain the severe difficulty people with these disorders have in tolerating treatments such as CPAP for sleep apnea. Several studies have pointed out the very poor compliance with treatment in returning veterans with PTSD. Although the airway opens immediately in response to treatment, it may take much longer for the limbic system and its stress response to return to normal. As a result, these individuals may continue to manifest very light sleep, claustrophobia, and a feeling of shortness of breath for a prolonged period. In turn, they frequently give up on the therapy. This is unfortunate because if they stick with it the majority will experience a real improvement in daytime symptoms as well.
Therefore, I have found that the key is to keep working with these patients. Most importantly, by explaining both the long-term benefits and the expected initial problems, we are able to achieve much better results than has been noted nationally.
Dr. Rosenberg wrote this article for Everyday Health.