title: Sleep spindle deficits in antipsychotic-naïve early course schizophrenia and in non-psychotic first-degree relatives.
abstract: BACKGROUND
  Chronic medicated patients with schizophrenia have marked reductions in sleep spindle activity and a correlated deficit in sleep-dependent memory consolidation. Using archival data, we investigated whether antipsychotic-naïve early course patients with schizophrenia and young non-psychotic first-degree relatives of patients with schizophrenia also show reduced sleep spindle activity and whether spindle activity correlates with cognitive function and symptoms.
  
  
  METHODS
  Sleep spindles during Stage 2 sleep were compared in antipsychotic-naïve adults newly diagnosed with psychosis, young non-psychotic first-degree relatives of schizophrenia patients and two samples of healthy controls matched to the patients and relatives. The relations of spindle parameters with cognitive measures and symptom ratings were examined.
  
  
  RESULTS
  Early course schizophrenia patients showed significantly reduced spindle activity relative to healthy controls and to early course patients with other psychotic disorders. Relatives of schizophrenia patients also showed reduced spindle activity compared with controls. Reduced spindle activity correlated with measures of executive function in early course patients, positive symptoms in schizophrenia and IQ estimates across groups.
  
  
  CONCLUSIONS
  Like chronic medicated schizophrenia patients, antipsychotic-naïve early course schizophrenia patients and young non-psychotic relatives of individuals with schizophrenia have reduced sleep spindle activity. These findings indicate that the spindle deficit is not an antipsychotic side-effect or a general feature of psychosis. Instead, the spindle deficit may predate the onset of schizophrenia, persist throughout its course and be an endophenotype that contributes to cognitive dysfunction.
authors.affiliation: Department of Psychiatry, Massachusetts General Hospital Charlestown, MA, USA ; Athinoula A. Martinos Center for Biomedical Imaging Charlestown, MA, USA ; Harvard Medical School Boston, MA, USA.
authors.forename: Dara S
authors.initials: DS
authors.lastname: Manoach
authors.affiliation: Department of Psychiatry, Massachusetts General Hospital Charlestown, MA, USA ; Athinoula A. Martinos Center for Biomedical Imaging Charlestown, MA, USA ; Harvard Medical School Boston, MA, USA.
authors.forename: Charmaine
authors.initials: C
authors.lastname: Demanuele
authors.affiliation: Harvard Medical School Boston, MA, USA ; Department of Psychiatry, Beth Israel Deaconess Medical Center Boston, MA, USA.
authors.forename: Erin J
authors.initials: EJ
authors.lastname: Wamsley
authors.affiliation: Athinoula A. Martinos Center for Biomedical Imaging Charlestown, MA, USA ; Harvard Medical School Boston, MA, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Vangel
authors.affiliation: Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine Pittsburgh, PA, USA.
authors.forename: Debra M
authors.initials: DM
authors.lastname: Montrose
authors.affiliation: Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine Pittsburgh, PA, USA.
authors.forename: Jean
authors.initials: J
authors.lastname: Miewald
authors.affiliation: Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine Pittsburgh, PA, USA.
authors.forename: David
authors.initials: D
authors.lastname: Kupfer
authors.affiliation: Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine Pittsburgh, PA, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Buysse
authors.affiliation: Harvard Medical School Boston, MA, USA ; Department of Psychiatry, Beth Israel Deaconess Medical Center Boston, MA, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Stickgold
authors.affiliation: Harvard Medical School Boston, MA, USA ; Department of Psychiatry, Beth Israel Deaconess Medical Center Boston, MA, USA ; Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine Pittsburgh, PA, USA.
authors.forename: Matcheri S
authors.initials: MS
authors.lastname: Keshavan
keywords: IQ; cognition; endophenotype; polysomnography; relatives; schizophrenia; sleep; sleep spindles