title: The role of genes and environment in shaping co-occurrence of DSM-IV defined anxiety dimensions among Italian twins aged 8-17.
abstract: This study investigated the ultimate causes of co-variation between symptoms of four common DSM-IV anxiety dimensions - Generalized Anxiety, Panic, Social Phobia and Separation Anxiety disorder - assessed with the Italian version of the Screen for Child Anxiety-Related Emotional Disorders questionnaire in a sample of 378 twin pairs aged 8-17 from the population-based Italian Twin Register. Genetic and environmental proportions of covariance between the targeted anxiety dimensions were estimated by multivariate twin analyses. Genetic influences (explaining from 58% to 99% of covariance) and unique environmental factors were the sole sources of co-variation for all phenotypes under study. Genetic influences associated with different anxiety dimensions coincide remarkably, as indicated by genetic correlations ranging from 0.40 to 0.61, while unique environmental overlap is less substantial. Thus, while additive genetic effects are important in explaining why children report symptoms from multiple anxiety disorders, environmental idiosyncratic factors seem to play a marginal role in shaping the co-occurrence of different anxiety dimensions in childhood.
authors.affiliation: The Academic Centre for the Study of Behavioural Plasticity, Vita-Salute San Raffaele University, Milan, Italy. ogliari.anna@hsr.it
authors.forename: Anna
authors.initials: A
authors.lastname: Ogliari
authors.forename: Chiara A
authors.initials: CA
authors.lastname: Spatola
authors.forename: Paola
authors.initials: P
authors.lastname: Pesenti-Gritti
authors.forename: Emanuela
authors.initials: E
authors.lastname: Medda
authors.forename: Luana
authors.initials: L
authors.lastname: Penna
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Stazi
authors.forename: Marco
authors.initials: M
authors.lastname: Battaglia
authors.forename: Corrado
authors.initials: C
authors.lastname: Fagnani
mesh_terms: D000293:Adolescent; D001008:Anxiety Disorders / Q000175:diagnosis / Q000209:etiology / Q000235:genetics*; D001010:Anxiety, Separation / Q000175:diagnosis / Q000209:etiology / Q000235:genetics*; D016009:Chi-Square Distribution; D002648:Child; D016001:Confidence Intervals; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004200:Diseases in Twins / Q000175:diagnosis / Q000209:etiology / Q000235:genetics* / Q000523:psychology; D005260:Female; D006801:Humans; D007558:Italy; D016013:Likelihood Functions; D008297:Male; D016584:Panic Disorder / Q000175:diagnosis / Q000209:etiology / Q000235:genetics*; D010641:Phenotype; D010698:Phobic Disorders / Q000175:diagnosis / Q000209:etiology / Q000235:genetics*; D011569:Psychiatric Status Rating Scales; D011581:Psychological Tests; D014429:Twins, Dizygotic / Q000523:psychology; D014430:Twins, Monozygotic / Q000523:psychology