1. Isn't there a contradiction between (a) privileging metaphors of "diagnosis" (playing a doctor) and (b) claiming at the same time that "acting as if one knows" is bad (or as you say, "psychotic")? According to your logic, your (or Lacan's/Zizek's) theory is bad.
2. As Carrol and Miles already mentioned, a "psychosis" is a misnomer and no longer even used in medicine. You are using an obsolete term that clinicians have decided not to use because it fails to serve the work of diagnosis. I suppose that the reader may be led to think that a theory that relies upon an obsolete term is likewise obsolete, but perhaps you don't care what the reader thinks.
>What packs more political punch: individualist consumerism in society
>is bad or it is psychotic?
3. "Political punch" -- if there is any -- comes from the unfortunate fact that many people think that being mentally ill is morally bad, a mental illness is a kind of "character flaw," etc. Saying "psychotic" when you actually mean "morally bad" reinforces the myth and implies that the mentally ill are "responsible" for their mental illness (since without "choice," there is no "ethics"). So, in this case, the "political punch" actually lands on the mentally ill.
4. It seems pointless & individualist to say "consumerism" is "bad."
Yoshie