We had been married for 13 years, it was a first marriage for both of us. We had one child, a son who I think was 6 the autumn I first noticed the strangeness (I'm getting my years confused now, I'd have to check my records). Neither of us have/had any other children. Our son was born with a physical defect which requires some accomodations in school but is otherwise a completly normal kid...he skis, played baseball, and can beat me at chess any time he sets his mind to it.
The September I first realized something was wrong was the year my son started to attend school full time. My ex had stayed home with him (this was a joint decision) but I had always assumed she would re-enter the work force, at least part time, certainly by the time he was in school for 6+ hours a day. As I said she had previously been energetic and ambitious in her career, and she had done quite a bit of very effective volunteer work (fundraising, etc) even after our son was born. But instead the delusions started: People were following her, talking about her. A good friend of hers had broken into our house to steal files off our computer. The principals office at the school was bugged, her conferences with him (it was one of her volunteer jobs) were being broadcast to other rooms so people could eavesdrop. Our cars and the house were bugged. People from our church were following her, etc, etc.
I've mentioned before my ex was never a very trusting person. She has a long history of a mutual scorched-earth relationship with her mother. She is not particularly close to her brother, her only sibling. She probably trusts her father more than anyone else but even he could not talk to her about the delusions. Many of her friends and family would call me out of the blue asking what was wrong with her, I had to tell them I didn't know. Her long work history was checkered with incidents where she claimed cowokers and management were conspiring against her.