I've had OCD since the age of 12 or 13, 'classic' (and crippling) OCD since the age of 19 or 20. In fact my OCD is now so severe that my house is actually a dusty, cluttered mess. Hand-washing, cleaning, ordering, arranging, symmetry, checking - I have them all. It's gotten worse over the years to where I can barely function as a human being and basically gave up on ever being 'normal' and 'catching up' with this mess, because cleaning one item or one tiny area of a room (a counter, for instance) can take an entire day. I've even run out of hot water OCD-rinsing an item.
I've been on all sorts of medications over the years (nothing right now), but none of them had any affect whatsoever on my OCD, though Klonopin once helped somewhat with the associated 'anxiety' (though not with the rituals themselves). I've been diagnosed with generalized seizures, independent, various types - mostly complex partials, but also simple partials and atonics.
I actually had my strep titers checked - they were fine. But I was diagnosed with Lyme Disease, and some doctors do believe in chronic Lyme. Also, staph in my bloodstream and high titers of several viruses - I know EBV was one of them, but there were others that were higher and I can't even remember which it was that was highest (memory problems). So I do believe an abnormal immune response to some past or present infection might be possible. Sometimes though I wonder if an untreated seizure disorder damaged my brain, essentially causing OCD?
I know too that I had a killer case of the chicken pox when I was a kid - I even have a scar on my face from it. Perhaps that has something to do with my OCD?
Psychologists and behavior therapy won't change anything for me - I would need someone to physically prevent me from OCD-ing to accomplish that, because when I'm face to face with any OCD task, any prior resolve to avoid OCD-ing gets smothered out. Sometimes I even shake when I'm OCD-ing, and I've even had several seizures (complex and partials) while OCD-ing.