title: Birth weight and obstetric complications determine age at onset in first episode of psychosis.
abstract: BACKGROUND
  Earlier age at onset of psychosis (AOP) has been associated with poor social adjustment and clinical outcome. Genetic and environmental factors such as obstetric complications, parental history of psychosis, advanced paternal age at time of birth, low birth weight and gestational age, and use of drugs have been described as bringing AOP forward. This study aims to evaluate the relationship between AOP and these factors in a sample of first episode of psychosis (FEP) patients.
  
  
  METHODS
  Clinical and sociodemographic data, age at FEP, age of parents at birth, parental history of psychosis, drug-use habits of the mother during pregnancy and of the patient before psychotic onset, and Lewis and Murray obstetric complication scale were obtained from 90 patients with FEP. Statistical analysis was performed by means of Pearson correlations, Chi-square tests, Student T-test analyses and a linear regression model using SPSS version 22.
  
  
  RESULTS
  Pre-eclampsia, need for incubator at birth, use of forceps, parental history of psychosis, and low birth weight were associated with an earlier AOP. Use of forceps and birth weight are the variables which best predict AOP in FEP. Stimulant drugs, which were mostly used together with cannabis and cocaine, were the only substances associated with an earlier AOP.
  
  
  CONCLUSIONS
  Our findings are consistent with previous study results and underline the role of the prenatal period in the development of psychosis and the importance of careful monitoring of pregnancy and delivery, especially in cases with familial history.
authors.affiliation: Research Unit, Parc Sanitari Sant Joan de Déu, Universitat de Barcelona (UB), CIBERSAM, GTRDSM, C/ Antoni Pujadas, 42, 08830, Sant Boi de Llobregat, Barcelona, Spain. Electronic address: rubio.elena@gmail.com.
authors.forename: E
authors.initials: E
authors.lastname: Rubio-Abadal
authors.affiliation: Research Unit, Parc Sanitari Sant Joan de Déu, Universitat de Barcelona (UB), CIBERSAM, GTRDSM, C/ Antoni Pujadas, 42, 08830, Sant Boi de Llobregat, Barcelona, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Ochoa
authors.affiliation: Research Unit, Centre d'Higiene Mental Les Corts, GTRDSM, Numància 107-109 Planta B, 08029, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Barajas
authors.affiliation: Research Unit, Parc Sanitari Sant Joan de Déu, Universitat de Barcelona (UB), CIBERSAM, GTRDSM, C/ Antoni Pujadas, 42, 08830, Sant Boi de Llobregat, Barcelona, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Baños
authors.affiliation: Psychiatry Department, Hospital Sant Joan de Déu, CIBERSAM, Passeig Sant Joan de Déu, 2, 08950, Esplugues de Llobregat, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Dolz
authors.affiliation: Psychiatry Department, Hospital Sant Joan de Déu, CIBERSAM, Passeig Sant Joan de Déu, 2, 08950, Esplugues de Llobregat, Barcelona, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Sanchez
authors.affiliation: Research Unit, Parc Sanitari Sant Joan de Déu, Universitat de Barcelona (UB), CIBERSAM, GTRDSM, C/ Antoni Pujadas, 42, 08830, Sant Boi de Llobregat, Barcelona, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Del Cacho
authors.affiliation: Research Unit, Parc Sanitari Sant Joan de Déu, Universitat de Barcelona (UB), CIBERSAM, GTRDSM, C/ Antoni Pujadas, 42, 08830, Sant Boi de Llobregat, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Carlson
authors.affiliation: Research Unit, Parc Sanitari Sant Joan de Déu, Universitat de Barcelona (UB), CIBERSAM, GTRDSM, C/ Antoni Pujadas, 42, 08830, Sant Boi de Llobregat, Barcelona, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Huerta-Ramos
authors.affiliation: Research Unit, Parc Sanitari Sant Joan de Déu, Universitat de Barcelona (UB), CIBERSAM, GTRDSM, C/ Antoni Pujadas, 42, 08830, Sant Boi de Llobregat, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Usall
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001724:Birth Weight / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008423:Maternal Age; D008875:Middle Aged; D010331:Paternal Age; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology / Q000503:physiopathology*; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000453:epidemiology* / Q000209:etiology*; D012044:Regression Analysis; D055815:Young Adult
keywords: Age of onset; Birth weight; Mtaternal age; Obstetric labor complications; Paternal age; Psychotic disorders/epidemiology