But now I can answer "yes," I believe I have found the cause of my insomnia. (And CiM actually mentions it in his/her comment!) Here's my story:
More than a year after my insomnia started on a regular basis, I moved into a new house. After a few months, I started experiencing various other health symptoms. I went to a long list of doctors (allergist, internist, rheumatologist, gynecologist, psychiatrist, acupuncturist, herbalist, sleep specialist, etc), with no answers. Finally after about a year or so, I went to an ear/nose/throat specialist, because one of my symptoms was an earache. He said to me "well, the tests done by all the other doctors have ruled out anything that might be causing these symptoms; do you by any chance have mold in your house? That's the only other thing I can think of."
I assured him that I had never seen any mold in my house. However, I called a mold inspector and had air tests done, and sure enough they came back positive for mold in the air, including the black mold that is most renowned for causing health problems. It turns out that the basement in my new house had mold behind all the paneling. Long story short, I had the basement demolished and waterproofed.
The first night after the basement was demolished, I felt better, with a slight improvement in my sleep. However, I still had sleep problems. I kept pursuing the various insomnia "cures" I blogged about in previous posts.
But one day I got to thinking: if an environmental irritant like mold had given me various aches and pains, could it be that I am sensitive to other environmental factors as well? I thought a lot about my symptoms and how they corresponded to certain times of my life. The first thing I tried was keeping my dog out of my bedroom. I also purchased an air purifier with a HEPA filter and ran it in my bedroom every night, all night.
My sleep improved significantly.
I then began taking further action to minimize dog dander inside the house by brushing my dog every day outside and washing him once per week. I also boarded my dog for a few weeks to see if that made any difference.
I am now convinced that my immune system is sensitive to dog dander and that this was the only or primary cause of my insomnia. (Even though I tested negative to the skin prick test for dog dander done by the allergist.)
I read a lot about different types of allergies (IgG, IgE) and the immune system (cytokines), and have to admit I didn't really understand it. But I understand this: some people are more sensitive to environmental factors than others, environmental factors can cause inflammation, inflammation can occur in the brain, and inflammation in the brain can lead to neuro/psych symptoms. (I call them neuro/psych because I honestly don't understand why we label some people with brain disorders as psych patients, and others as neuro patients -- it seems like a ridiculous and very unfair distinction to me).
The last connection I made to my insomnia was with my menstrual cycle. My insomnia occurred all the time, but got worse in the days before my period. I began taking supplements that are supposed to help minimize hormonal swings. At first a supplement called DIM was helpful, but it stopped working. Now I am taking an herb called Shatavari which is helpful. It seems to me that hormones, like any other chemical or irritant, may also cause inflammation in the brain in some people.
Back to CiM, who wrote: "My insomnia began very abruptly with a toxic chemical exposure." Coincidence?
I strongly believe that environmental sensitivity was the key to my insomnia. The amazing thing is that I now sleep through the night almost every night. I can't say it is the most restful sleep I've ever had, but maybe that will happen after my current dog passes on. I haven't lived in a dog-free home in 17 years. While I didn't have insomnia the entire time, I did have other symptoms that may be related, and I may have just gotten more sensitive over time.
My dog, of course, is bummed that he can't sleep in my bed anymore, but he's gotten used to the fact that he has to sleep in another room.
To CiM, since you know you are sensitive to some chemicals, I would encourage you to think creatively about what else might be in your home that could be causing an immune reaction, such as a pet or mold. Maybe that could be contributing to your insomnia also.
To anyone who is interested in more information on the scientific aspects of immune system, inflammation, and neuro/psych symptoms, I've found some relevant articles from credible sources that are peer-reviewed. I've posted links to them below (note that they may focus on "mental illness," but I don't see why a similar immune system reaction couldn't cause insomnia rather than depression):
Is depression a kind of allergic reaction?
From inflammation to sickness and depression: when the immune system subjugates the brain
Mind and body: Scientists identify immune system link to mental illness
Mental Health: Molding a Link to Depression
I hope this blog post is helpful to others, including CiM. I know not everyone has environmental sensitivities (I read somewhere that about 25% of people are sensitive to mold), but perhaps this will help some people who have insomnia.
And I'll blog again in the future if I continue to learn more. I think I still need to blog on my sleep study. Please feel free to post your stories here also and let me know if any of this information is helpful to you.
