title: Cortical thickness correlates of psychotic experiences: examining the effect of season of birth using a genetically informative design.
abstract: Season of birth has been shown to influence risk for several neuropsychiatric diseases. Furthermore, it has been suggested that season of birth modifies a number of brain morphological traits. Since cortical thickness alterations have been reported across some levels of the psychosis-spectrum, this study was aimed at i) assessing the scarcely explored relationship between cortical thickness and severity of subclinical psychotic experiences (PEs) in healthy subjects, and ii) evaluating the potential impact of season of birth in the preceding thickness-PEs relationship. As both PEs and brain cortical features are heritable, the current work used monozygotic twins to separately evaluate familial and unique environmental factors. High-resolution structural MRI scans of 48 twins (24 monozygotic pairs) were analyzed to estimate cortical thickness using FreeSurfer. They were then examined in relation to PEs, accounting for the effects of birth season; putative differential relationships between PEs and cortical thickness depending on season of birth were also tested. Current results support previous findings indicative of cortical thickening in healthy individuals with high psychometrically assessed psychosis scores, probably in line with theories of compensatory aspects of brain features in non-clinical populations. Additionally, they suggest distinct patterns of cortical thickness-PEs relationships depending on birth seasonality. Familial factors underlying the presence of PEs may drive these effects.
authors.affiliation: Unidad de Antropología, Departamento de Biología Animal, Facultad de Biología and Instituto de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal, 643, 08028 Barcelona, Spain; Centro de Investigaciones Biomédicas en Red de Salud Mental (CIBERSAM), C/Doctor Esquerdo, 46, 28007 Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Córdova-Palomera
authors.affiliation: Unidad de Antropología, Departamento de Biología Animal, Facultad de Biología and Instituto de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal, 643, 08028 Barcelona, Spain; Centro de Investigaciones Biomédicas en Red de Salud Mental (CIBERSAM), C/Doctor Esquerdo, 46, 28007 Madrid, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Alemany
authors.affiliation: Medical Image Core Facility, the Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), C/Rosselló, 149-153, 08036 Barcelona, Spain; Centro de Investigación Biomédica en Red en Bioingeniería, Biomedicina y Nanomedicina (CIBER-BBN), C/Poeta Mariano Esquillor, s/n, 50018 Zaragoza, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Falcón
authors.affiliation: Centro de Investigaciones Biomédicas en Red de Salud Mental (CIBERSAM), C/Doctor Esquerdo, 46, 28007 Madrid, Spain; Medical Image Core Facility, the Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), C/Rosselló, 149-153, 08036 Barcelona, Spain; Centro de Diagnóstico por Imagen, Hospital Clínico, C/Villarroel, 170, 08036 Barcelona, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Bargalló
authors.affiliation: Unidad de Antropología, Departamento de Biología Animal, Facultad de Biología and Instituto de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal, 643, 08028 Barcelona, Spain; Centro de Investigaciones Biomédicas en Red de Salud Mental (CIBERSAM), C/Doctor Esquerdo, 46, 28007 Madrid, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Goldberg
authors.affiliation: Centro de Investigaciones Biomédicas en Red de Salud Mental (CIBERSAM), C/Doctor Esquerdo, 46, 28007 Madrid, Spain; University Hospital Marqués de Valdecilla, Department of Psychiatry, School of Medicine, University of Cantabria, Av. Valdecilla, s/n, 39008 Santander, Cantabria, Spain; IFIMAV, Instituto de Formación e Investigación Marqués de Valdecilla, Av. Valdecilla, s/n, 39008 Santander, Cantabria, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Crespo-Facorro
authors.affiliation: Department of Psychiatry and Psychotherapy, Jena University Hospital, Friedrich Schiller University Jena, Philosophenweg 3, 07743 Jena, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Nenadic
authors.affiliation: Unidad de Antropología, Departamento de Biología Animal, Facultad de Biología and Instituto de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal, 643, 08028 Barcelona, Spain; Centro de Investigaciones Biomédicas en Red de Salud Mental (CIBERSAM), C/Doctor Esquerdo, 46, 28007 Madrid, Spain. Electronic address: lfananas@ub.edu.
authors.forename: L
authors.initials: L
authors.lastname: Fañanás
mesh_terms: D002540:Cerebral Cortex / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D009929:Organ Size; D011594:Psychometrics; D011618:Psychotic Disorders / Q000473:pathology* / Q000503:physiopathology*; D012621:Seasons; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic
keywords: Cortical thickness; MRI; Monozygotic twins; Psychotic experiences; Season of birth; Winter/Spring