APA (2000). Diagnostic and Statistical Manual of Mental Disorders, 4th edn, revised. American Psychiatric Association: Washington, DC.
Asherson P, Gurling H (2012). Quantitative and molecular genetics of ADHD. Current Topics in Behavioral Neuroscience 9, 239–272.
Barrett P (2007). Structural equation modelling: adjudging model fit. Personality and Individual Differences 42, 815–824.
Bishop DVM, Baird G (2001). Parent and teacher report of pragmatic aspects of communication: use of the Children's Communication Checklist in a clinical setting. Developmental Medicine and Child Neurology 43, 809–818.
Burt SA, McGue M, Krueger RF, Iacono WG (2005). How are parent–child conflict and externalizing symptoms related over time? Results from a genetically-informative cross-lagged study. Development and Psychopathology 17, 145–165.
Clark T, Feehan C, Tinline C, Vostanis P (1999). Autistic symptoms in children with attention deficit-hyperactivity disorder. European Child and Adolescent Psychiatry 8, 50–55.
Conners CK, Sitarenios G, Park JDA, Epstein JN (1998). The revised Conners' Parent Rating Scale (CPRS-R): factor structure, reliability, and criterion validity. Journal of Abnormal Child Psychology 26, 257–268.
de Bruin EI, Ferdinand RF, Meester S, de Nijs PFA, Verheij F (2007). High rates of psychiatric co-morbidity in PDD-NOS. Journal of Autism and Developmental Disorders 37, 877–886.
Goldsmith HH (1991). A zygosity questionnaire for young adults: a research note. Behavior Genetics 21, 257–269.
Greven CU, Asherson P, Rijsdijk F, Plomin R (2011). A longitudinal twin study on the association between inattentive and hyperactive-impulsive ADHD symptoms. Journal of Abnormal Child Psychology 39, 623–632.
Hall JG (2003). Twinning. Lancet 362, 735–743.
Hallett V, Ronald A, Rijsdijk F, Happé F (2010). Association of autistic-like and internalizing traits during childhood: a longitudinal twin study. American Journal of Psychiatry 167, 809–817.
Happé F, Ronald A (2008). Fractionable autism triad: a review of evidence from behavioural, genetic, cognitive, and neural research. Neuropsychology Review 18, 287–304.
Happé F, Ronald A, Plomin R (2006). Time to give up on a single explanation for autism. Nature Neuroscience 9, 1218–1220.
Kenny DA (1975). Cross-lagged panel correlation: a test for spuriousness. Psychological Bulletin 82, 887–903.
Kuntsi J, Rijsdijk F, Ronald A, Asherson P, Plomin R (2005). Genetic influences on the stability of attention-deficit/hyperactivity disorder symptoms from early to middle childhood. Biological Psychiatry 57, 647–654.
Leonard MA, Milich S, Lorch EP (2011). The role of pragmatic language use in mediating the relation between hyperactivity and inattention and social skills problems. Journal of Speech, Language, and Hearing Research 54, 567–579.
Lichtenstein P, Carlström E, Råstam M, Gillberg C, Anckarsäter H (2010). The genetics of autism spectrum disorders and related neuropsychiatric disorders in childhood. American Journal of Psychiatry 167, 1357–1363.
Lundström S, Chang Z, Kerekes N, Gumpert CH, Råstam M, Gillberg C, Lichtenstein P, Anckarsäter H (2011). Autistic-like traits and their association with mental health problems in two nationwide twin cohorts of children and adults. Psychological Medicine 41, 2423–2433.
McLoughlin G, Ronald A, Kuntsi J, Asherson P, Plomin R (2007). Genetic support for the dual nature of attention deficit hyperactivity disorder: substantial genetic overlap between the inattentive and hyperactive-impulsive components. Journal of Abnormal Child Psychology 35, 999–1008.
Mulligan A, Anney RJL, O'Regan M, Chen W, Butler L, Fitzgerald M, Buitelaar J, Steinhausen H, Rothenberger A, Minderaa A, Nijmeijer J, Hoekstra PJ, Oades RD, Roeyers H, Buschgens C, Christiansen H, Franke B, Gabriels I, Hartman C, Kuntsi J, Marco R, Meidad S, Mueller U, Psychogiou L, Rommelse N, Thompson M, Uebel H, Banaschewski T, Ebstein R, Eisenberg J, Manor I, Miranda A, Mulas F, Sergeant J, Sonuga-Barke E, Asherson P, Faraone SV, Gill M (2009). Autism symptoms in attention-deficit/hyperactivity disorder: a familial trait which correlates with conduct, oppositional defiant, and language and motor disorders. Journal of Autism and Developmental Disorders 39, 197–209.
Neale MC, Boker SM, Xie G, Maes HM (2003). Mx: Statistical Modelling. Virginia Commonwealth University: Richmond, VA.
Neale MC, Røysamb E, Jacobson K (2006). Multivariate genetic analysis of sex limitation and G x E interaction. Twin Research and Human Genetics 9, 481–489.
Nijmeijer J, Hoekstra PJ, Minderaa RB, Buitelaar JK, Altink ME, Buschgens CJM, Fliers EA, Rommelse NNJ, Sergeant JA, Hartman CA (2009). PDD symptoms in ADHD, an independent familial trait? Journal of Abnormal Child Psychology 37, 443–453.
Nikolas MA, Burt SA (2010). Genetic and environmental influences on ADHD symptom dimensions of inattention and hyperactivity: a meta-analysis. Journal of Abnormal Psychology 119, 1–17.
Oliver BR, Plomin R (2007). Twins' Early Development Study (TEDS): a multivariate, longitudinal investigation of language, cognition and behavior problems from childhood through adolescence. Twin Research and Human Genetics 10, 96–105.
Plomin R, DeFries JC, McClearn GE, McGuffin P (2008). Behavioral Genetics. Worth Publishers: New York.
Price TS, Freeman B, Craig I, Petrill SA, Ebersole L, Plomin R (2000). Infant zygosity can be assigned by parental report questionnaire data. Twin Research 3, 129–133.
Reiersen AM, Constantino JN, Grimmer M, Martin NG, Todd RD (2008). Evidence for shared genetic influences on self-reported ADHD and autistic symptoms in young adult Australian twins. Twin Research and Human Genetics 11, 579–585.
Reiersen AM, Constantino JN, Volk HE, Todd RD (2007). Autistic traits in a population-based ADHD twin sample. Journal of Child Psychiatry and Psychology 48, 464–472.
Robinson EB, Munir K, Munafo MR, Hughes M, McCormick MC, Koenen KC (2011). Stability of autistic traits in the general population: further evidence for a continuum of impairment. Journal of the American Academy of Child and Adolescent Psychiatry 50, 376–384.
Ronald A, Edelson LR, Asherson P, Saudino KJ (2010 a). Exploring the relationship between autistic-like traits and ADHD behaviours in early childhood: findings from a community twin study of 2-year-olds. Journal of Abnormal Child Psychology 38, 185–196.
Ronald A, Happé F, Bolton P, Butcher LM, Price TS, Wheelwright S, Baron-Cohen S, Plomin R (2006). Genetic heterogeneity between the three components of the autism spectrum: a twin study. Journal of the American Academy of Child and Adolescent Psychiatry 45, 691–699.
Ronald A, Happé F, Dworzynski K, Bolton P, Plomin R (2010 b). Exploring the relation between prenatal and neonatal complications and later autistic-like features in a representative community sample of twins. Child Development 81, 166–182.
Ronald A, Hoekstra RA (2011). Autism spectrum disorders and autistic traits: a decade of new twin studies. American Journal of Medical Genetics, Part B: Neuropsychiatric Genetics 156, 255–274.
Ronald A, Simonoff E, Kuntsi J, Asherson P, Plomin R (2008). Evidence for overlapping genetic influences on autistic and ADHD behaviours in a community twin study. Journal of Child Psychology and Psychiatry 49, 535–542.
Scott FJ, Baron-Cohen S, Bolton P, Brayne C (2002). The CAST (Childhood Asperger Syndrome Test): preliminary development of a UK screen for mainstream primary-school-age children. Autism 6, 9–31.
Simonoff E, Pickles A, Charman T, Chandler S, Loucas T, Baird G (2008). Psychiatric disorders in children with autism spectrum disorders: prevalence, comorbidity, and associated factors in a population-derived sample. Journal of the American Academy of Child and Adolescent Psychiatry 47, 921–929.
St Pourcain B, Mandy WP, Heron J, Golding J, Davey Smith G, Skuse DH (2011). Links between co-occurring social-communication and hyperactive-inattentive trait trajectories. Journal of the American Academy of Child and Adolescent Psychiatry 50, 892–902.
Turkheimer E, Waldron M (2000). Nonshared environment: a theoretical, methodological, and quantitative review. Psychological Bulletin 126, 78–108.
Whitehouse AJO, Hickey M, Ronald A (2011). Are autistic traits in the general population stable across development? PLoS One 6, e23029.
Williams J, Scott F, Stott C, Allison C, Baron-Cohen S, Brayne C (2005). The CAST (Childhood Asperger Syndrome Test): test accuracy. Autism 9, 45–68.
Yoshida Y, Uchiyama T (2004). The clinical necessity for assessing Attention deficit/hyperactivity disorder (AD/HD) symptoms in children with high-functioning pervasive developmental disorder (PDD). European Child and Adolescent Psychiatry 13, 307–314.