The authors compared 21 “Kraepelinian” schizophrenic patients who had been ill and dependent on others for the past 5 years with 76 chronic schizophrenic patients in remission or with exacerbations requiring hospitalization. The Kraepelinian patients met the criteria for schizophrenia by more diagnostic systems than the exacerbated patients, were less responsive to haloperidol, had more severe negative symptoms, and had similarly severe positive symptoms.

Keefe RSE, Mohs RC, Losonczy MF, Davidson M, Silverman JM, Kendler KS, Nora R, Horvath TB, Davis KL. Characteristics of very poor outcome schizophrenia. American Journal of Psychiatry, 1987; 144(7): 889-895.