title: Brain volume change in first-episode psychosis: an effect of antipsychotic medication independent of BMI change.
abstract: OBJECTIVE
  The effect of antipsychotic medication on brain structure remains unclear. Given the prevalence of weight gain as a side-effect, body mass index (BMI) change could be a confounder.
  
  
  METHODS
  Patients with first-episode psychosis (n = 78) and healthy controls (n = 119) underwent two 1.5T MRI scans with a 1-year follow-up interval. siena (fsl 5.0) was used to measure whole-brain volume change. Weight and height were measured at both time points. Antipsychotic medication use at baseline and follow-up was converted into chlorpromazine equivalent dose and averaged.
  
  
  RESULTS
  Patients did not show significantly larger brain volume loss compared with healthy controls. In the whole sample (n = 197), BMI change was negatively associated with brain volume change (β = -0.19, P = 0.008); there was no interaction effect of group. Among patients, higher antipsychotic medication dosage was associated with greater brain volume loss (β = -0.45, P < 0.001). This association was not affected by adjusting for BMI change.
  
  
  CONCLUSIONS
  Weight gain was related to brain volume reductions to a similar degree among patients and controls. Antipsychotic dosage-related reductions of brain volume were not confounded by BMI change. Generalizability to contexts involving severe weight gain needs to be established. Furthermore, disentangling effects of medication from illness severity remains a challenge.
authors.affiliation: Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway.|NORMENT and K.G. Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: K N
authors.identifier: http://orcid.org/0000-0002-5751-4809
authors.initials: KN
authors.lastname: Jørgensen
authors.affiliation: Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway.|Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: R
authors.initials: R
authors.lastname: Nesvåg
authors.affiliation: Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway.
authors.forename: S
authors.initials: S
authors.lastname: Nerland
authors.affiliation: Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway.|NORMENT and K.G. Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: L
authors.initials: L
authors.lastname: Mørch-Johnsen
authors.affiliation: NORMENT and K.G. Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.|Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway.|Department of Psychology, University of Oslo, Oslo, Norway.
authors.forename: L T
authors.initials: LT
authors.lastname: Westlye
authors.affiliation: Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway.|NORMENT and K.G. Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: E H
authors.initials: EH
authors.lastname: Lange
authors.affiliation: Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway.|NORMENT and K.G. Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: U K
authors.initials: UK
authors.lastname: Haukvik
authors.affiliation: Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway.|NORMENT and K.G. Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: C B
authors.initials: CB
authors.lastname: Hartberg
authors.affiliation: NORMENT and K.G. Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.|Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway.
authors.forename: I
authors.initials: I
authors.lastname: Melle
authors.affiliation: NORMENT and K.G. Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.|Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway.
authors.forename: O A
authors.initials: OA
authors.lastname: Andreassen
authors.affiliation: Department of Psychiatric Research, Diakonhjemmet Hospital, Oslo, Norway.|NORMENT and K.G. Jebsen Center for Psychosis Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: I
authors.initials: I
authors.lastname: Agartz
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015992:Body Mass Index; D001921:Brain / Q000000981:diagnostic imaging* / Q000187:drug effects; D002746:Chlorpromazine / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000188:drug therapy*; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D002746:Chlorpromazine
keywords: antipsychotic agents; bipolar disorder; magnetic resonance imaging; schizophrenia; weight gain