['To evaluate a common genetic variant, sulfotransferase 4A1 haplotype 1 (SULT4A1-1), as a predictor of hospitalization events due to the exacerbation of schizophrenia for patients treated with antipsychotic medications. Haplotypes were determined using single nucleotide polymorphism data.', 'The study included 417 white subjects from the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study with a DSM-IV diagnosis of schizophrenia. Patients were assigned to 1 of 4 atypical antipsychotics (olanzapine, quetiapine, risperidone, or ziprasidone) or to the first-generation antipsychotic perphenazine. Kaplan-Meier survival analysis and Cox proportional hazards regression models were used to measure if haplotype status impacted hospitalization events for these 5 treatments. Haplotype status was evaluated for its relationship to hospitalization events regardless of treatment and for the individual treatments, with or without previous exacerbation. Data for the CATIE study were collected from January 2001 to December 2004. The current post hoc analysis was performed between May 2011 and August 2011.', 'In phase 1 of the trial, considering only the first hospitalization events, the haplotype had a significant impact on hospitalization events, with a hazard ratio for SULT4A1-1(-) versus SULT4A1-1(+) of 2.54 (P = .048). When prior exacerbation was included in the model for phase 1, the hazard ratio was 2.34 (P = .072) considering only the first hospitalization event and 2.71 (P = .039) considering all hospitalization events in the phase. When data for all phases were evaluated, SULT4A1-1(-) status was associated with increased hospitalization risk for subjects treated with olanzapine, with a hazard ratio of 8.26 (P = .041), and possibly for subjects treated with quetiapine, with a hazard ratio of 6.80 (P = .070).'] Does sulfotransferase 4A1 Haplotype 1 ( SULT4A1-1 ) be Associated With Decreased Hospitalization Events in Antipsychotic-Treated Patients With Schizophrenia?