Diagnosis and treatment of schizophrenia.

The present invention provides methods and compositions for screening, diagnosis and prognosis of Schizophrenia, for monitoring the effectiveness of Schizophrenia treatment, identifying patients most likely to respond to a particular therapeutic treatment and for drug development. Schizophrenia-Associated Features (SFs), detectable by two-dimensional electrophoresis of cerebrospinal fluid, serum or plasma are described. The invention further provides Schizophrenia-Associated Protein Isoforms (SPIs) detectable in cerebrospinal fluid, serum or plasma, preparations comprising SPIs, antibodies immunospecific for SPIs, and kits comprising the aforesaid.