Sleep Apnea can be very complex as it can have both physical and mental causes. Usually sleep apnea is caused by not enough air is entering the lungs that produces a choking sensation. This sensation causes the sleeper to awake and in some cases produces anixety and fear.
Complex sleep apnea is a form of apnea which the brain does not signal the system to breathe. Regular apnea is treated with a cpap for obstructed breathing. Complex Apnea has a treatment called vpap adapt sv. Thie has been having good results for people.