Has anyone (this would likely be asked by an ME/CFS patient with insomnia!) asked a "real" ME/CFS specialist what they think the difference is between patients who can sleep on their own, unmedicated, and those who can not fall/stay asleep without medication? (Granted,I am sure it will be non-refreshing even for those who can sleep without medication) I am wondering, has any doctor been able to pin down some difference between "sleepers" and "non-sleepers" on a genetic, chemical, etc. level? I am thinking, this could also be a major factor for who is able to tolerate certain medications.