No, unfortunately they haven't. The family doctor I see, not being that familiar with CF immediately jumped the gun and thought it was stress or depression. I have been suffering from it for 5 years, in periods with and without stress. I would be willing to try an antidepressant to see if there is any benefit though.
The only 2 times where there was a substantial improvement in my sleep, and again for only about 2 days, was when I received IV meds voluntarily for a sinus infection (zosyn) and when I took a 325mg iron sulfate pill at night. I still woke up tired on the pill, but when I took a nap for an hour and woke up, I worked for 6-7 hours straight on some reading.