title: The Extent and Specificity of Relative Age Effects on Mental Health and Functioning in Early Adolescence.
abstract: OBJECTIVE
  Although extensive evidence indicates that being younger within a school cohort is associated with poorer academic functioning, much less is known about such relative age effects (RAEs) for mental health--the focus of the current investigation.
  
  
  METHODS
  Data from 23,379 11- to 13-year-olds attending state-maintained secondary schools in England were analyzed to investigate RAEs on mental health measured using the Strengths and Difficulties Questionnaire. Participants were grouped into oldest, middle, and youngest thirds of their academic year based on their month of birth relative to their cohort. Hierarchical linear regression analysis evaluated RAEs and gender- or deprivation-related moderation of such effects.
  
  
  RESULTS
  Relatively younger adolescents had significantly more emotional symptoms and peer problems compared with relatively older individuals in a year group, although effect sizes were small. These effects were not moderated by gender or deprivation. Impact of mental health difficulties on other aspects of functioning was also greater among relatively younger children. Larger RAEs are observed in the younger cohort (11-12 years) compared with those in the 12- to 13-year-olds, thereby indicating that RAEs might attenuate with age.
  
  
  CONCLUSIONS
  Being relatively younger than classmates is associated with increased internalizing symptoms, poorer peer relationships, and higher impact of mental health difficulties on functioning at school and home. The findings support wider inclusion of relative age in understanding mental health difficulties and its inclusion as a potential risk factor in studies investigating the development of psychopathology, especially for internalizing symptoms. Possible mechanisms of the effects detected are discussed.
authors.affiliation: Clinical, Educational and Health Psychology, University College London, London, United Kingdom; Evidence Based Practice Unit, University College London and Anna Freud Centre, London, United Kingdom. Electronic address: praveetha.patalay.11@ucl.ac.uk.
authors.forename: Praveetha
authors.initials: P
authors.lastname: Patalay
authors.affiliation: Department of Human Ecology, University of California, Davis, Davis, California.
authors.forename: Jay
authors.initials: J
authors.lastname: Belsky
authors.affiliation: Clinical, Educational and Health Psychology, University College London, London, United Kingdom.
authors.forename: Peter
authors.initials: P
authors.lastname: Fonagy
authors.affiliation: Greenwood Institute of Child Health, University of Leicester, Leicester, United Kingdom.
authors.forename: Panos
authors.initials: P
authors.lastname: Vostanis
authors.affiliation: Manchester Institute of Education, University of Manchester, Manchester, United Kingdom.
authors.forename: Neil
authors.initials: N
authors.lastname: Humphrey
authors.affiliation: Evidence Based Practice Unit, University College London and Anna Freud Centre, London, United Kingdom.
authors.forename: Jessica
authors.initials: J
authors.lastname: Deighton
authors.affiliation: Evidence Based Practice Unit, University College London and Anna Freud Centre, London, United Kingdom.
authors.forename: Miranda
authors.initials: M
authors.lastname: Wolpert
mesh_terms: D000293:Adolescent; D000342:Affective Symptoms; D000367:Age Factors; D002648:Child; D016208:Databases, Factual; D004739:England; D005260:Female; D006801:Humans; D008297:Male; D008603:Mental Health; D010379:Peer Group; D000297:Psychology, Adolescent; D012574:Schools; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires
keywords: Age within cohort; Children; Relative age; School; Well-being