To understand a little something about the evolution of insight, paranoia and depression during early schizophrenia, one might do well to begin with Pickles and Haddock. Their most pertinent published study is:
Drake, R.J.; Pickles, A.; Bentall, R.P.; Kinderman, P.; Haddock, G.; Tarrier, N.; & Lewis, S.W. (2004). The evolution of insight, paranoia and depression during early schizophrenia. Psychological Medicine. 34, (2) 285-292.
NOTE: This post at first contained a fishy error, mentioning “Pickles and Herring” rather than the correct “Pickles and Haddock”. Sorry about that.