title: Cognitive effectiveness of olanzapine and risperidone in first-episode psychosis.
abstract: BACKGROUND
  Cognitive impairment in schizophrenia-spectrum disorders is highly prevalent and notably influences functional outcomes.
  
  
  OBJECTIVE
  To characterise the cognitive effectiveness of second-generation antipsychotic drugs.
  
  
  METHODS
  One hundred consecutive and previously unmedicated patients with first-episode schizophrenia-spectrum disorders were admitted. Seventy-seven completed baseline, 1-month and 6-month psychopathological and neuropsychological assessments. Patients were randomised to risperidone or olanzapine treatment. Four final treatment allocation groups were defined since patients continued treatment in their normal setting: risperidone, olanzapine, mixed and no-antipsychotic groups.
  
  
  RESULTS
  There were no differences in cognitive effectiveness between the four treatment groups. Reliable change index methods demonstrated that nearly a half of patients showed an improvement in Global Cognitive Score at the 6-month assessment. Improvement on the neuropsychological tests ranged from 17 to 54%. A strong predictor of cognitive response was poor performance on baseline neuropsychological tests; response was moderately influenced by a low premorbid scholastic performance and IQ.
  
  
  CONCLUSIONS
  Cognitive improvement related to second-generation antipsychotic drugs appeared within the first 4 weeks of treatment and persisted at 6 months irrespective of treatment group. Greater cognitive dysfunction at baseline and lower premorbid cognitive background predicted cognitive improvement in our sample.
authors.affiliation: Psychiatric Unit, Virgen del Camino Hospital c/Irunlarrea 4, Pamplona E-31008, Spain. mcuestaz@cfnavarra.es
authors.forename: Manuel J
authors.initials: MJ
authors.lastname: Cuesta
authors.forename: Elena Garcíade
authors.initials: EG
authors.lastname: Jalón
authors.forename: M Soledad
authors.initials: MS
authors.lastname: Campos
authors.forename: Victor
authors.initials: V
authors.lastname: Peralta
mesh_terms: D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001569:Benzodiazepines / Q000627:therapeutic use*; D003071:Cognition / Q000187:drug effects*; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D000077152:Olanzapine; D011618:Psychotic Disorders / Q000188:drug therapy* / Q000523:psychology; D018967:Risperidone / Q000627:therapeutic use*; D012559:Schizophrenia / Q000188:drug therapy*; D013223:Statistics as Topic; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D001569:Benzodiazepines; D018967:Risperidone; D000077152:Olanzapine