...suspicious attitude and tendency to engage in argumentation...

I suppose it might have been "intricate argumentation" or something like that, but it would probably be going overboard to add a qualifier.

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Note added at 52 mins (2008-06-05 18:27:54 GMT)
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I'm just trying to think if the medical people use a technical term for this compulsive argumentation, or compulsive hyper-ratiocination (!), or whatever it might be. But I'm not aware of one. I mean what Olga said in her comment (which I saw after posting.)

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Note added at 57 mins (2008-06-05 18:33:10 GMT)
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Hey, "hyperratiocination" is a word! But, I found it in a description of Conan Doyle literary career, not psychiatry (though there may be some overlap): "The novel marks the beginning of the end of his hyperratiocination phase that had begun with the Sherlock Holmes tales..."

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Note added at 1 hr (2008-06-05 18:37:09 GMT)
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Several psychology texts use "compulsive internal dialogue," but I don't know how "internal" the behavior your text describes is. "...tendency to engage in compulsive internal dialogue" sounds good, but may be too far afield.