title: Effects of sex, menstrual cycle phase, and endogenous hormones on cognition in schizophrenia.
abstract: BACKGROUND
  In women with schizophrenia, cognition has been shown to be enhanced following administration of hormone therapy or oxytocin. We examined how natural hormonal changes across the menstrual cycle influence cognition in women with schizophrenia. We hypothesized that female patients would perform worse on "female-dominant" tasks (verbal memory/fluency) and better on "male-dominant" tasks (visuospatial) during the early follicular phase (low estradiol and progesterone) compared to midluteal phase (high estradiol and progesterone) in relation to estradiol but not progesterone.
  
  
  METHODS
  Fifty-four women (23 with schizophrenia) completed cognitive assessments and provided blood for sex steroid assays and oxytocin at early follicular (days 2-4) and midluteal (days 20-22) phases. Men were included to verify the expected pattern of sex differences on cognitive tests.
  
  
  RESULTS
  Expected sex differences were observed on "female-dominant" and "male-dominant" tasks (p<0.001), but the magnitude of those differences did not differ between patients and controls (p=0.44). Cognitive performance did not change across the menstrual cycle on "female-dominant" or "male-dominant" tasks in either group. Estradiol and progesterone levels were unrelated to cognitive performance. Oxytocin levels did not change across the menstrual cycle but were positively related to performance on "female-dominant" tasks in female patients only (p<0.05).
  
  
  CONCLUSIONS
  Sex differences in cognitive function are preserved in schizophrenia. Oxytocin levels do not change across the cycle, but relate to enhanced performance on female dominant tests in women. Physiological levels of oxytocin may thus have a more powerful benefit in some cognitive domains than estrogens in schizophrenia.
authors.affiliation: Department of Psychiatry, Women's Mental Health Research Program, University of Illinois at Chicago, Chicago, IL, USA. Electronic address: lrubin@psych.uic.edu.
authors.forename: Leah H
authors.initials: LH
authors.lastname: Rubin
authors.affiliation: Kinsey Institute, Indiana University, IN, USA.
authors.forename: C Sue
authors.initials: CS
authors.lastname: Carter
authors.affiliation: Department of Psychiatry, Women's Mental Health Research Program, University of Illinois at Chicago, Chicago, IL, USA; Department of Physiology and Pharmacology and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.
authors.forename: Lauren L
authors.initials: LL
authors.lastname: Drogos
authors.affiliation: Psychiatry, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Hossein
authors.initials: H
authors.lastname: Pournajafi-Nazarloo
authors.affiliation: Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Sweeney
authors.affiliation: Department of Psychiatry, Women's Mental Health Research Program, University of Illinois at Chicago, Chicago, IL, USA; Department of Psychology, University of Illinois at Chicago, USA.
authors.forename: Pauline M
authors.initials: PM
authors.lastname: Maki
mesh_terms: D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D003071:Cognition / Q000502:physiology*; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D008297:Male; D008597:Menstrual Cycle / Q000097:blood*; D009483:Neuropsychological Tests; D010121:Oxytocin / Q000097:blood*; D011618:Psychotic Disorders / Q000097:blood / Q000188:drug therapy / Q000523:psychology*; D012559:Schizophrenia / Q000097:blood / Q000188:drug therapy; D012565:Schizophrenic Psychology; D012727:Sex Characteristics; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D012739:Gonadal Steroid Hormones; D010121:Oxytocin
keywords: Cognition; Estrogen; Menstrual cycle; Oxytocin; Schizophrenia; Sex differences