Here is a fascinating article (at least to me) about a possible link between sleep-related breathing disorders like obstructive sleep apnea and other disorders. The other disorders are classified as "functional", meaning no etiology is agreed upon, such as fibromyalgia, chronic fatigue syndrome, and migraines. The other disorders include anxiety disorders like panic attacks and post-traumatic stress disorder (PTSD).
The researcher that is discussed in article is Dr. Gold at Stony Brook University and has published research studies on this topic. His theories about how mild OSA disorders can worsen functional and anxiety disorders is not without controversy. However, if further research confirms his theories, treatment for OSA may also help these difficult-to-treat disorders.