title: Verbal working memory in schizophrenia from the Consortium on the Genetics of Schizophrenia (COGS) study: the moderating role of smoking status and antipsychotic medications.
abstract: OBJECTIVE
  Working memory impairment has been extensively studied in schizophrenia, but less is known about moderators of the impairment. Using the Consortium on the Genetics of Schizophrenia case-control study (COGS-2), we examined smoking status, types of antipsychotic medication, and history of substance as moderators for working memory impairment in schizophrenia.
  
  
  METHODS
  From 5 sites, 1377 patients with schizophrenia or schizoaffective, depressed type and 1037 healthy controls completed the letter-number span (LNS) task. The LNS uses intermixed letter and digit stimuli that increase from 2 up to 8 stimuli. In the forward condition, participants repeated the letters and numbers in the order they were presented. In the reorder condition, participants repeated the digits in ascending order followed by letters in alphabetical order.
  
  
  RESULTS
  Schizophrenia patients performed more poorly than controls, with a larger difference on reorder than forward conditions. Deficits were associated with symptoms, functional capacity, and functional outcome. Patients who smoked showed larger impairment than nonsmoking patients, primarily due to deficits on the reorder condition. The impairing association of smoking was more pronounced among patients taking first-generation than those taking second-generation antipsychotic medications. Correlations between working memory and community functioning were stronger for nonsmokers. History of substance use did not moderate working memory impairment.
  
  
  CONCLUSIONS
  Results confirm the working memory impairment in schizophrenia, and indicate smoking status as an important moderator for these deficits. The greater impairment in smokers may reflect added burden of smoking on general health or that patients with greater deficits are more likely to smoke.
authors.affiliation: Department of Psychiatry and Biobehavioral Science, Geffen School of Medicine, University of California Los Angeles, CA, United States; VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States. Electronic address: jungheelee@ucla.edu.
authors.forename: Junghee
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Psychiatry and Biobehavioral Science, Geffen School of Medicine, University of California Los Angeles, CA, United States; VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Green
authors.affiliation: Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, United States.
authors.forename: Monica E
authors.initials: ME
authors.lastname: Calkins
authors.affiliation: Department of Psychiatry, University of California San Diego, La Jolla, CA, United States.
authors.forename: Tiffany A
authors.initials: TA
authors.lastname: Greenwood
authors.affiliation: Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, United States.
authors.forename: Raquel E
authors.initials: RE
authors.lastname: Gur
authors.affiliation: Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, United States.
authors.forename: Ruben C
authors.initials: RC
authors.lastname: Gur
authors.affiliation: Department of Psychiatry and Behavioral Science, Stanford University, Stanford, CA United States; Department of Pediatrics, Stanford University, Stanford, CA, United States.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Lazzeroni
authors.affiliation: Department of Psychiatry, University of California San Diego, La Jolla, CA, United States; VISN22, Mental Illness Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, United States.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Light
authors.affiliation: Department of Psychiatry and Biobehavioral Science, Geffen School of Medicine, University of California Los Angeles, CA, United States.
authors.forename: Keith H
authors.initials: KH
authors.lastname: Nuechterlein
authors.affiliation: Department of Psychiatry and Behavioral Science, University of Washington, Seattle, WA, United States; VA Puget Sound Healthcare System, Seattle, WA, United States.
authors.forename: Allen D
authors.initials: AD
authors.lastname: Radant
authors.affiliation: Department of Psychiatry, Harvard Medical School, Boston, MA, United States; Massachusetts Mental Health Center Public Psychiatry Devision of the Beth Israel Deaconess Medical Center, Boston, MA, United States.
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Seidman
authors.affiliation: Department of Psychiatry, The Mount Sinai School of Medicine, New York, NY, United States; James J. Peters VA Medical Center, New York, NY, United States.
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Siever
authors.affiliation: Department of Psychiatry, The Mount Sinai School of Medicine, New York, NY, United States; James J. Peters VA Medical Center, New York, NY, United States.
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Silverman
authors.affiliation: Department of Psychiatry, University of California San Diego, La Jolla, CA, United States; VISN22, Mental Illness Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, United States.
authors.forename: Joyce
authors.initials: J
authors.lastname: Sprock
authors.affiliation: Department of Psychiatry, Harvard Medical School, Boston, MA, United States; Massachusetts Mental Health Center Public Psychiatry Devision of the Beth Israel Deaconess Medical Center, Boston, MA, United States.
authors.forename: William S
authors.initials: WS
authors.lastname: Stone
authors.affiliation: Department of Psychiatry and Biobehavioral Science, Geffen School of Medicine, University of California Los Angeles, CA, United States; VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States; Department of Biostatistics, University of California Los Angeles, CA, United States.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Sugar
authors.affiliation: Department of Psychiatry, University of California San Diego, La Jolla, CA, United States.
authors.forename: Neal R
authors.initials: NR
authors.lastname: Swerdlow
authors.affiliation: Department of Psychiatry and Behavioral Science, University of Washington, Seattle, WA, United States; VA Puget Sound Healthcare System, Seattle, WA, United States.
authors.forename: Debby W
authors.initials: DW
authors.lastname: Tsuang
authors.affiliation: Department of Psychiatry, University of California San Diego, La Jolla, CA, United States; Institute for Genomic Medicine, University of California, San Diego, CA, United States; Harvard Institute of Psychiatry Epidemiology and Genetics, Boston, MA, United States.
authors.forename: Ming T
authors.initials: MT
authors.lastname: Tsuang
authors.affiliation: Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, United States.
authors.forename: Bruce I
authors.initials: BI
authors.lastname: Turetsky
authors.affiliation: Department of Psychiatry, University of California San Diego, La Jolla, CA, United States; VISN22, Mental Illness Research, Education and Clinical Center (MIRECC), VA San Diego Healthcare System, San Diego, CA, United States.
authors.forename: David L
authors.initials: DL
authors.lastname: Braff
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D058068:Endophenotypes; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects; D011939:Mental Recall / Q000187:drug effects; D008875:Middle Aged; D009483:Neuropsychological Tests; D011618:Psychotic Disorders / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology / Q000523:psychology; D021641:Recognition, Psychology / Q000187:drug effects; D012559:Schizophrenia / Q000150:complications* / Q000188:drug therapy* / Q000235:genetics / Q000503:physiopathology; D012565:Schizophrenic Psychology; D012907:Smoking / Q000503:physiopathology / Q000523:psychology*; D013067:Speech Perception / Q000187:drug effects; D014706:Verbal Learning / Q000187:drug effects; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents
keywords: Antipsychotic medication; Letter–Number span; Moderators; Schizophrenia; Smoking; Verbal working memory