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The Child and Adolescent Twin Study in Sweden (CATSS)

The aim of this study is to investigate how both genetic and environmental effects influence health and behavior in children and adolescents.

Project description

We initiated the ongoing CATSS study in 2004. In CATSS-9, we conduct a telephone interview with parents of all 1,400 twin pairs born in Sweden annually in connection with their 9th birthdays. By April 2014 we have performed 13,500 interviews with a high response rate (≈80%), and we have collected DNA from the twins (current N≈14,000 individuals). We follow these families with questionnaires to parents and twins at age 15 (CATSS-15; current N=5,553) and 18 (CATSS-18; current N=2,663 twins) (1).

CATSS is very large and thus has power to study rare conditions and identify subgroups of twins for follow up studies. Since we have information from 10 age cohorts assessed with the same measure we can here investigate how mental health problems among children have changed over time. There is one completed high-risk clinical study (at age 15; CATSS-DOGSS: N=227 twin pairs), four ongoing (CATSS-9-clinic; CATSS-RATSS [ASD]; CATSS-asthma; CATSS-OCD [obsessive compulsive disorder/hoarding). In CATSS-9-clinic we do clinical examinations on twins who screen positive for a neurodevelopmental disorder in the CATSS-9 screening. The main aim is to understand health service inequalities, and to identify factors that predict contact with child and adolescent psychiatry services.

Using the CATSS data we have shown that the heritability for ASD was around 80% and that ASD had a common genetic etiology with other neuropsychiatric disorders (2), that extreme values of ASD (3) and ADHD (4) have the same genetic etiology as normal variation in the underlying traits, and an association between fetal growth on ASD suggesting that fetal growth is in the causal pathway (5). At least 11 theses and 30 papers have up to now been published from the CATSS-study.

CATSS is a part of several international projects where data from different countries is used to reach better and more convincing conclusions. This gives us the opportunity to compare how things are alike but also different in different countries.

One of the project is called ACTION and aims to investigate aggression. You can read more about this project on the separate website.

Project leader

Paul Lichtenstein

Telefon:08-524 874 24


We are happy to answer your questions and can be reached by e-mail to

Project period: 2004-ongoing


Project staff

Camilla Palm

Telefon:08-524 844 49

Isabelle Kizling

Telefon:08-524 823 07

Yi Lu

Mark Taylor

Telefon:08-524 822 67

Martin Cederlöf

Erik Pettersson

Published theses

Ongoing thesis work


Investigating the childhood symptom profile of community-based individuals diagnosed with attention-deficit/hyperactivity disorder as adults.
Taylor M, Larsson H, Gillberg C, Lichtenstein P, Lundström S
J Child Psychol Psychiatry 2019 Mar;60(3):259-266

Aggressive behaviour in childhood and adolescence: the role of smoking during pregnancy, evidence from four twin cohorts in the EU-ACTION consortium.
Malanchini M, Smith-Woolley E, Ayorech Z, Rimfeld K, Krapohl E, Vuoksimaa E, et al
Psychol Med 2019 Mar;49(4):646-654

Physical health in children with neurodevelopmental disorders.
Alabaf S, Gillberg C, Lundström S, Lichtenstein P, Kerekes N, Råstam M, et al
J Autism Dev Disord 2019 Jan;49(1):83-95

Association of Genetic Risk Factors for Psychiatric Disorders and Traits of These Disorders in a Swedish Population Twin Sample.
Taylor MJ, Martin J, Lu Y, Brikell I, Lundström S, Larsson H, et al
JAMA Psychiatry 2018 Dec;():

Svensson O, Sorman K, Durbeej N, Lichtenstein P, Anckarsater H, Kerekes N, Nilsson T. Associations Between Conduct Disorder, Neurodevelopmental Problems and Psychopathic Personality Traits in a Swedish Twin Youth Population. J Psychopathol Behav 2018;40:586-92.

The Associations between Callous-unemotional Traits and Symptoms of Conduct Problems, Hyperactivity and Emotional Problems: A Study of Adolescent Twins Screened for Neurodevelopmental Problems.
Saunders MC, Anckarsäter H, Lundström S, Hellner C, Lichtenstein P, Fontaine NMG
J Abnorm Child Psychol 2019 Mar;47(3):447-457

Childhood neurodevelopmental disorders and risk of coercive sexual victimization in childhood and adolescence - a population-based prospective twin study.
Ohlsson Gotby V, Lichtenstein P, Långström N, Pettersson E
J Child Psychol Psychiatry 2018 Sep;59(9):957-965

Sex-specific manifestation of genetic risk for attention deficit hyperactivity disorder in the general population.
Martin J, Taylor MJ, Rydell M, Riglin L, Eyre O, Lu Y, et al
J Child Psychol Psychiatry 2018 Aug;59(8):908-916

Copy number variation and neuropsychiatric problems in females and males in the general population.
Martin J, Tammimies K, Karlsson R, Lu Y, Larsson H, Lichtenstein P, et al
Am. J. Med. Genet. B Neuropsychiatr. Genet. 2018 Oct;():

The Quantified Behavioral Test Failed to Differentiate ADHD in Adolescents With Neurodevelopmental Problems.
Johansson V, Norén Selinus E, Kuja-Halkola R, Lundström S, Durbeej N, Anckarsäter H, et al
J Atten Disord 2018 Jul;():1087054718787034

Air Pollution Exposure During Pregnancy and Symptoms of Attention Deficit and Hyperactivity Disorder in Children in Europe.
Forns J, Sunyer J, Garcia-Esteban R, Porta D, Ghassabian A, Giorgis-Allemand L, et al
Epidemiology 2018 09;29(5):618-626

Prevalence and heritability of body dysmorphic symptoms in adolescents and young adults: a population-based nationwide twin study.
Enander J, Ivanov VZ, Mataix-Cols D, Kuja-Halkola R, Ljótsson B, Lundström S, et al
Psychol Med 2018 Dec;48(16):2740-2747

The contribution of common genetic risk variants for ADHD to a general factor of childhood psychopathology.
Brikell I, Larsson H, Lu Y, Pettersson E, Chen Q, Kuja-Halkola R, et al
Mol. Psychiatry 2018 Jun;():

Childhood aggression and the co-occurrence of behavioural and emotional problems: results across ages 3-16 years from multiple raters in six cohorts in the EU-ACTION project.
Bartels M, Hendriks A, Mauri M, Krapohl E, Whipp A, Bolhuis K, et al
Eur Child Adolesc Psychiatry 2018 Sep;27(9):1105-1121

Secular changes in the symptom level of clinically diagnosed autism.
Arvidsson O, Gillberg C, Lichtenstein P, Lundström S
J Child Psychol Psychiatry 2018 Jul;59(7):744-751

Etiological influences on the stability of autistic traits from childhood to early adulthood: evidence from a twin study.
Taylor MJ, Gillberg C, Lichtenstein P, Lundström S
Mol Autism 2017 ;8():5

The coexistence of psychiatric and gastrointestinal problems in children with restrictive eating in a nationwide Swedish twin study.
Täljemark J, Råstam M, Lichtenstein P, Anckarsäter H, Kerekes N
J Eat Disord 2017 ;5():25

Genetic and environmental contributions to the association between ADHD and affective problems in early childhood-A Swedish population-based twin study.
Rydell M, Taylor MJ, Larsson H
Am. J. Med. Genet. B Neuropsychiatr. Genet. 2017 Jul;174(5):538-546

Fetal Growth and Childhood Lung Function in the Swedish Twin Study on Prediction and Prevention of Asthma.
Örtqvist AK, Ullemar V, Lundholm C, Kuja-Halkola R, Magnusson PKE, Lichtenstein P, et al
Ann Am Thorac Soc 2017 Jul;14(7):1147-1153

Heritability of hoarding symptoms across adolescence and young adulthood: A longitudinal twin study.
Ivanov VZ, Nordsletten A, Mataix-Cols D, Serlachius E, Lichtenstein P, Lundström S, et al
PLoS ONE 2017 ;12(6):e0179541

Familial Factors, Victimization, and Psychological Health Among Sexual Minority Adolescents in Sweden.
Donahue K, Långström N, Lundström S, Lichtenstein P, Forsman M
Am J Public Health 2017 02;107(2):322-328

Maltreatment-associated neurodevelopmental disorders: a co-twin control analysis.
Dinkler L, Lundström S, Gajwani R, Lichtenstein P, Gillberg C, Minnis H
J Child Psychol Psychiatry 2017 Jun;58(6):691-701

Disentangling Heterogeneity of Childhood Disruptive Behavior Problems Into Dimensions and Subgroups.
Bolhuis K, Lubke GH, van der Ende J, Bartels M, van Beijsterveldt CEM, Lichtenstein P, et al
J Am Acad Child Adolesc Psychiatry 2017 Aug;56(8):678-686

Fetal and postnatal metal dysregulation in autism.
Arora M, Reichenberg A, Willfors C, Austin C, Gennings C, Berggren S, et al
Nat Commun 2017 06;8():15493

Further investigations of the relation between polymorphisms in sex steroid related genes and autistic-like traits.
Zettergren A, Karlsson S, Hovey D, Jonsson L, Melke J, Anckarsäter H, et al
Psychoneuroendocrinology 2016 06;68():1-5

Heritability and confirmation of genetic association studies for childhood asthma in twins.
Ullemar V, Magnusson PK, Lundholm C, Zettergren A, Melén E, Lichtenstein P, et al
Allergy 2016 Feb;71(2):230-8

Is There a Female Protective Effect Against Attention-Deficit/Hyperactivity Disorder? Evidence From Two Representative Twin Samples.
Taylor MJ, Lichtenstein P, Larsson H, Anckarsäter H, Greven CU, Ronald A
J Am Acad Child Adolesc Psychiatry 2016 06;55(6):504-512.e2

Childhood attention-deficit/hyperactivity disorder symptoms and the development of adolescent alcohol problems: A prospective, population-based study of Swedish twins.
Quinn PD, Pettersson E, Lundström S, Anckarsäter H, Långström N, Gumpert CH, et al
Am. J. Med. Genet. B Neuropsychiatr. Genet. 2016 10;171(7):958-70

The genetic and environmental structure of the character sub-scales of the temperament and character inventory in adolescence.
Lester N, Garcia D, Lundström S, Brändström S, Råstam M, Kerekes N, et al
Ann Gen Psychiatry 2016 ;15():10

Antisocial behavior and polymorphisms in the oxytocin receptor gene: findings in two independent samples.
Hovey D, Lindstedt M, Zettergren A, Jonsson L, Johansson A, Melke J, et al
Mol. Psychiatry 2016 07;21(7):983-8

Effect of co-twin gender on neurodevelopmental symptoms: a twin register study.
Eriksson JM, Lundström S, Lichtenstein P, Bejerot S, Eriksson E
Mol Autism 2016 ;7():8

The association between childhood autistic traits and adolescent psychotic experiences is explained by general neuropsychiatric problems.
Cederlöf M, Pettersson E, Sariaslan A, Larsson H, Östberg P, Kelleher I, et al
Am. J. Med. Genet. B Neuropsychiatr. Genet. 2016 Mar;171B(2):153-9

Predictors of adolescents' consent to use health records for research and results from data collection in a Swedish twin cohort.
Ullemar V, Lundholm C, Örtqvist AK, Gumpert CH, Anckarsäter H, Lundström S, et al
Twin Res Hum Genet 2015 Jun;18(3):256-65

Childhood neurodevelopmental problems and adolescent bully victimization: population-based, prospective twin study in Sweden.
Törn P, Pettersson E, Lichtenstein P, Anckarsäter H, Lundström S, Hellner Gumpert C, et al
Eur Child Adolesc Psychiatry 2015 Sep;24(9):1049-59

Birth weight as an independent predictor of ADHD symptoms: a within-twin pair analysis.
Pettersson E, Sjölander A, Almqvist C, Anckarsäter H, D'Onofrio BM, Lichtenstein P, et al
J Child Psychol Psychiatry 2015 Apr;56(4):453-9

Childhood Symptoms of ADHD Overrule Comorbidity in Relation to Psychosocial Outcome at Age 15: A Longitudinal Study.
Norén Selinus E, Molero Y, Lichtenstein P, Larson T, Lundström S, Anckarsäter H, et al
PLoS ONE 2015 ;10(9):e0137475

Personality and intelligence: persistence, not self-directedness, cooperativeness or self-transcendence, is related to twins' cognitive abilities.
Mousavi F, Rozsa S, Nilsson T, Archer T, Anckarsäter H, Garcia D
PeerJ 2015 ;3():e1195

Multimodal brain imaging in autism spectrum disorder and the promise of twin research.
Mevel K, Fransson P, Bölte S
Autism 2015 Jul;19(5):527-41

Autism spectrum disorders and coexisting disorders in a nationwide Swedish twin study.
Lundström S, Reichenberg A, Melke J, Råstam M, Kerekes N, Lichtenstein P, et al
J Child Psychol Psychiatry 2015 Jun;56(6):702-10

Autism phenotype versus registered diagnosis in Swedish children: prevalence trends over 10 years in general population samples.
Lundström S, Reichenberg A, Anckarsäter H, Lichtenstein P, Gillberg C
BMJ 2015 Apr;350():h1961

Neurodevelopmental problems and extremes in BMI.
Kerekes N, Tajnia A, Lichtenstein P, Lundström S, Anckarsäter H, Nilsson T, et al
PeerJ 2015 ;3():e1024

Impact of asthma medication and familial factors on the association between childhood asthma and attention-deficit/hyperactivity disorder: a combined twin- and register-based study: Epidemiology of Allergic Disease.
Holmberg K, Lundholm C, Anckarsäter H, Larsson H, Almqvist C
Clin. Exp. Allergy 2015 May;45(5):964-973

Cohort Profile: Swedish Twin Study on Prediction and Prevention of Asthma (STOPPA).
Almqvist C, Örtqvist AK, Ullemar V, Lundholm C, Lichtenstein P, Magnusson PK
Twin Res Hum Genet 2015 Jun;18(3):273-80

Willfors C, Ronald A, Berggren S, L. P, Lichtenstein P, Anckarsater H, Coco C, Bölte S. On the role of non-shared environment for executive functioning in ADHD: a twin-differences design study Int J Dev Disabilities 2014;60:163-73.

Symptoms of autism and ADHD: a Swedish twin study examining their overlap.
Ronald A, Larsson H, Anckarsäter H, Lichtenstein P
J Abnorm Psychol 2014 May;123(2):440-51

Reliability of Autism-Tics, AD/HD, and other Comorbidities (A-TAC) inventory in a test-retest design.
Larson T, Kerekes N, Selinus EN, Lichtenstein P, Gumpert CH, Anckarsäter H, et al
Psychol Rep 2014 Feb;114(1):93-103

Oppositional defiant- and conduct disorder-like problems: neurodevelopmental predictors and genetic background in boys and girls, in a nationwide twin study.
Kerekes N, Lundström S, Chang Z, Tajnia A, Jern P, Lichtenstein P, et al
PeerJ 2014 ;2():e359

Association study between autistic-like traits and polymorphisms in the autism candidate regions RELN, CNTNAP2, SHANK3, and CDH9/10.
Jonsson L, Zettergren A, Pettersson E, Hovey D, Anckarsäter H, Westberg L, et al
Mol Autism 2014 ;5(1):55

Association between ASMT and autistic-like traits in children from a Swedish nationwide cohort.
Jonsson L, Anckarsäter H, Zettergren A, Westberg L, Walum H, Lundström S, et al
Psychiatr. Genet. 2014 Feb;24(1):21-7

Associations between oxytocin-related genes and autistic-like traits.
Hovey D, Zettergren A, Jonsson L, Melke J, Anckarsäter H, Lichtenstein P, et al
Soc Neurosci 2014 ;9(4):378-86

Relative immaturity and ADHD: findings from nationwide registers, parent- and self-reports.
Halldner L, Tillander A, Lundholm C, Boman M, Långström N, Larsson H, et al
J Child Psychol Psychiatry 2014 Aug;55(8):897-904

Motor function and perception in children with neuropsychiatric and conduct problems: results from a population based twin study.
Gustafsson P, Kerekes N, Anckarsäter H, Lichtenstein P, Gillberg C, Råstam M
J Neurodev Disord 2014 ;6(1):11

Exposure to air pollution from traffic and neurodevelopmental disorders in Swedish twins.
Gong T, Almqvist C, Bölte S, Lichtenstein P, Anckarsäter H, Lind T, et al
Twin Res Hum Genet 2014 Dec;17(6):553-62

Responsibility and cooperativeness are constrained, not determined.
Garcia D, Stråge A, Lundström S, Radovic S, Brändström S, Råstam M, et al
Front Psychol 2014 ;5():308

Language and mathematical problems as precursors of psychotic-like experiences and juvenile mania symptoms.
Cederlöf M, Ostberg P, Pettersson E, Anckarsäter H, Gumpert C, Lundström S, et al
Psychol Med 2014 Apr;44(6):1293-302

The Roots of Autism and ADHD Twin Study in Sweden (RATSS).
Bölte S, Willfors C, Berggren S, Norberg J, Poltrago L, Mevel K, et al
Twin Res Hum Genet 2014 Jun;17(3):164-76

Associations between polymorphisms in sex steroid related genes and autistic-like traits.
Zettergren A, Jonsson L, Johansson D, Melke J, Lundström S, Anckarsäter H, et al
Psychoneuroendocrinology 2013 Nov;38(11):2575-84

Examining and interpreting the female protective effect against autistic behavior.
Robinson EB, Lichtenstein P, Anckarsäter H, Happé F, Ronald A
Proc. Natl. Acad. Sci. U.S.A. 2013 Mar;110(13):5258-62

Eating problems and overlap with ADHD and autism spectrum disorders in a nationwide twin study of 9- and 12-year-old children.
Råstam M, Täljemark J, Tajnia A, Lundström S, Gustafsson P, Lichtenstein P, et al
ScientificWorldJournal 2013 ;2013():315429

Different neurodevelopmental symptoms have a common genetic etiology.
Pettersson E, Anckarsäter H, Gillberg C, Lichtenstein P
J Child Psychol Psychiatry 2013 Dec;54(12):1356-65

A study of the possible association between adenosine A2A receptor gene polymorphisms and attention-deficit hyperactivity disorder traits.
Molero Y, Gumpert C, Serlachius E, Lichtenstein P, Walum H, Johansson D, et al
Genes Brain Behav. 2013 Apr;12(3):305-10

The Swedish Twin Registry: establishment of a biobank and other recent developments.
Magnusson PK, Almqvist C, Rahman I, Ganna A, Viktorin A, Walum H, et al
Twin Res Hum Genet 2013 Feb;16(1):317-29

Predictive properties of the A-TAC inventory when screening for childhood-onset neurodevelopmental problems in a population-based sample.
Larson T, Lundström S, Nilsson T, Selinus EN, Råstam M, Lichtenstein P, et al
BMC Psychiatry 2013 Sep;13():233

ADHD, autism spectrum disorder, temperament, and character: phenotypical associations and etiology in a Swedish childhood twin study.
Kerekes N, Brändström S, Lundström S, Råstam M, Nilsson T, Anckarsäter H
Compr Psychiatry 2013 Nov;54(8):1140-7

Prevalence, comorbidity and heritability of hoarding symptoms in adolescence: a population based twin study in 15-year olds.
Ivanov V, Mataix-Cols D, Serlachius E, Lichtenstein P, Anckarsäter H, Chang Z, et al
PLoS ONE 2013 ;8(7):e69140

Temperament and character in the Child and Adolescent Twin Study in Sweden (CATSS): comparison to the general population, and genetic structure analysis.
Garcia D, Lundström S, Brändström S, Råstam M, Cloninger C, Kerekes N, et al
PLoS ONE 2013 ;8(8):e70475

Self-directedness and cooperativeness, psychosocial dysfunction and suffering in ESSENCE.
Garcia D, Anckarsäter H, Lundström S
ScientificWorldJournal 2013 ;2013():416981

Childhood behavior problems and adolescent sexual risk behavior: familial confounding in the child and adolescent twin study in Sweden (CATSS).
Donahue KL, Lichtenstein P, Lundström S, Anckarsäter H, Gumpert CH, Långström N, et al
J Adolesc Health 2013 May;52(5):606-12

Variation in the oxytocin receptor gene is associated with pair-bonding and social behavior.
Walum H, Lichtenstein P, Neiderhiser J, Reiss D, Ganiban J, Spotts E, et al
Biol. Psychiatry 2012 Mar;71(5):419-26

Autism spectrum disorders and autistic like traits: similar etiology in the extreme end and the normal variation.
Lundström S, Chang Z, Råstam M, Gillberg C, Larsson H, Anckarsäter H, et al
Arch. Gen. Psychiatry 2012 Jan;69(1):46-52

Lower birth weight indicates higher risk of autistic traits in discordant twin pairs.
Losh M, Esserman D, Anckarsäter H, Sullivan PF, Lichtenstein P
Psychol Med 2012 May;42(5):1091-102

Childhood attention-deficit hyperactivity disorder as an extreme of a continuous trait: a quantitative genetic study of 8,500 twin pairs.
Larsson H, Anckarsater H, Råstam M, Chang Z, Lichtenstein P
J Child Psychol Psychiatry 2012 Jan;53(1):73-80

A twin study of autism symptoms in Sweden.
Ronald A, Larsson H, Anckarsäter H, Lichtenstein P
Mol. Psychiatry 2011 Oct;16(10):1039-47

Autistic-like traits and their association with mental health problems in two nationwide twin cohorts of children and adults.
Lundström S, Chang Z, Kerekes N, Gumpert CH, Råstam M, Gillberg C, et al
Psychol Med 2011 Nov;41(11):2423-33

Heritability of cortisol regulation in children.
Gustafsson PA, Gustafsson PE, Anckarsäter H, Lichtenstein P, Ljung T, Nelson N, et al
Twin Res Hum Genet 2011 Dec;14(6):553-61

The Child and Adolescent Twin Study in Sweden (CATSS).
Anckarsäter H, Lundström S, Kollberg L, Kerekes N, Palm C, Carlström E, et al
Twin Res Hum Genet 2011 Dec;14(6):495-508

Trajectories leading to autism spectrum disorders are affected by paternal age: findings from two nationally representative twin studies.
Lundström S, Haworth CM, Carlström E, Gillberg C, Mill J, Råstam M, et al
J Child Psychol Psychiatry 2010 Jul;51(7):850-6

Impaired fetal growth decreases the risk of childhood atopic eczema: a Swedish twin study.
Lundholm C, Ortqvist AK, Lichtenstein P, Cnattingius S, Almqvist C
Clin. Exp. Allergy 2010 Jul;40(7):1044-53

The genetics of autism spectrum disorders and related neuropsychiatric disorders in childhood.
Lichtenstein P, Carlström E, Råstam M, Gillberg C, Anckarsäter H
Am J Psychiatry 2010 Nov;167(11):1357-63

The autism--tics, AD/HD and other comorbidities inventory (A-TAC): further validation of a telephone interview for epidemiological research.
Larson T, Anckarsäter H, Gillberg C, Ståhlberg O, Carlström E, Kadesjö B, et al
BMC Psychiatry 2010 Jan;10():1

The Swedish version of the parent-rated Junior Temperament and Character Inventory (J-TCI).
Kerekes N, Brändström S, Ståhlberg O, Larson T, Carlström E, Lichtenstein P, et al
Psychol Rep 2010 Dec;107(3):715-25

The Autism--Tics, AD/HD and other Comorbidities (A-TAC) telephone interview: convergence with the Child Behavior Checklist (CBCL).
Halleröd SL, Larson T, Ståhlberg O, Carlström E, Gillberg C, Anckarsäter H, et al
Nord J Psychiatry 2010 May;64(3):218-24

Does quantity have a quality all its own? Cumulative adversity and up- and down-regulation of circadian salivary cortisol levels in healthy children.
Gustafsson PE, Anckarsäter H, Lichtenstein P, Nelson N, Gustafsson PA
Psychoneuroendocrinology 2010 Oct;35(9):1410-5

Familial factors do not confound the association between birth weight and childhood asthma.
Ortqvist AK, Lundholm C, Carlström E, Lichtenstein P, Cnattingius S, Almqvist C
Pediatrics 2009 Oct;124(4):e737-43

Anckarsater H, Larson T, Hansson SL, Carlstrom E, Stahlberg O, Gillberg C, Rastam M, Gillberg C, Lichtenstein P. Child Neurodevelopmental and Behavioural Problems are Intercorrelated and Dimensionally Distributed in the General Population. The Open Psychiatry Journal 2008;2:5-11.

The Swedish Twin Registry in the third millennium: an update.
Lichtenstein P, Sullivan PF, Cnattingius S, Gatz M, Johansson S, Carlström E, et al
Twin Res Hum Genet 2006 Dec;9(6):875-82