As some have stated, FM is probably caused by a combination of factors, genetic vulnerability, a trigger of some sort, etc. This is not hard to believe as this is the case for many psychiatric conditions and medical conditions like heart disease and cancer too.
In my case, my insomnia was so troubling, and I was so reluctant to get stuck on the one drug which really helped me sleep (Klonopin), I had two sleep studies done. The first before Klonopin, the second while I was on it. Both studies showed a similar problem, grossly decreased or nearly absent deep sleep (stage 3,4 and REM-now they combine 3&4 to just "3"). Klonopin caused more actual time asleep but the additional sleep time was in stage 1&2. Trazodone can actually increase deep sleep but I just cant tolerate it. I know I have had short periods of clearly better sleep and without fail my FM symptoms temporarily improve.
But this is just one factor...this is one complex condition which no doubt has many other facets. I cant believe some of the things which have developed...chemical sensitivities, food allergies, flushing and sweats, near paralysis like weakness upon arising 3-4x per month, urinary retention...this is enough to make you think you are crazy. I am learning how to avoid all triggers...this helps, but your life starts revolving around this damn disease.
I welcome this forum...it means alot to hear others' experiences. Doc Byrd