I don't know if anybody is following this thread any more, since there are no new postings, but being the Virgo I am, I want to follow up on my posting from April 26 with the latest developments.
My son has now for two weeks been on a further reduced 0.625 mg dose of Zyprexa (1/4 of the original 2.5 mg dose) plus 3mg Melatonin for sleeping, at bedtime every night. When we cut down from 1.25 to 0.625mg he again experienced a bout of insomnia. He could still be awake and talking to himself 3 or even 4 hours beyond bed time. However, within two weeks this has regularized, and he now typically sleeps between 1 and 2 hours after lights out.
His daytime behavior is more or less unchanged. Talkative and possibly a little more active than before, but his teachers in his special school say that he is staying well within limits of expected behavior.
Since we originally (5 years ago) put him on Zyprexa mainly for behavior control, I have now concluded, that anti-psychotic medication may not at all be the right thing for him. After another month we will take him to his psychiatrist and get him totally off Zyprexa and try to find another category of medication for controlling his excessive talking to himself.
Unless something dramatic happens, I will not bother you any more with this story, which may be a bit off topic, since it relates to a mentally retarded person and not a case of "regular" schizophrenia. Anyway, it represents one variation on the theme "Zyprexa withdrawal horror stories".