Latent Class Analysis of Antisocial Behavior Inte

Authors: James J Li Steve S Lee

Publish Date: 2010/04/20

Volume: 38, Issue: 6, Pages: 789-801

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Abstract

To improve understanding about genetic and environmental influences on antisocial behavior ASB we tested the association of the 44base pair polymorphism of the serotonin transporter gene 5HTTLPR and maltreatment using latent class analysis in 2488 boys and girls from Wave 1 of the National Longitudinal Study of Adolescent Health In boys ASB was defined by three classes Exclusive Covert Mixed Covert and Overt and No Problems whereas in girls ASB was defined by two classes Exclusive Covert No Problems In boys 5HTTLPR and maltreatment were not significantly related to ASB However in girls maltreatment but not 5HTTLPR was significantly associated with ASB A significant interaction between 5HTTLPR and maltreatment was also observed where maltreated girls homozygous for the short allele were 12 times more likely to be classified in the Exclusive Covert group than in the No Problems group Structural differences in the latent structure of ASB at Wave 2 and Wave 3 prevented repeat LCA modeling However using counts of ASB 5HTTLPR maltreatment and its interaction were unrelated to overt and covert ASB at Wave 2 and only maltreatment was related to covert ASB at Wave 3 We discuss these findings within the context of sex differences in ASB and relevant models of geneenvironment interplay across developmental periodsAntisocial behavior ASB is defined by acts that violate established norms/rules eg truancy curfew aggression resulting in interpersonal harm eg violence assault or property damage eg fire setting Dishion and Patterson 2006 ASB is one of the most common referrals for youth mental health services in the United States Kazdin et al 2006 Disruptive behavior disorders including oppositional defiant disorder ODD and attentiondeficit/hyperactivity disorder ADHD were the most prevalent disorders in an epidemiological sample of 4 yearold children Lavigne et al 2009 Externalizing behavior is clinically significant because it strongly predicts academic failure and adult psychopathology eg antisocial personality disorder and it is highly persistent over time Farrington 1995 In fact stability estimates for aggression and ASB are comparable to IQ which has long been considered as one of the most stable individual attributes Olweus 1979 ASB is also responsible for significant economic consequences In the United States the cost of health care academic support and juvenile justice was approximately 70000 more for youths with conduct disorder CD than youth without CD over a seven year period Foster and Jones 2005 Thus ASB is an important constellation of problems with clinical and public health significanceExisting models have differentiated dimensions of ASB based on separable risk factors underlying mechanisms and divergent patterns of association including overt eg fighting bullying and covert eg lying stealing ASB Loeber and Schmaling 1985 Frick et al 1993 In a study of 391 preschool children overt ASB was more strongly associated with hyperactivity conduct problems and classroom conflict than covert ASB Willoughby et al 2001 In two separate samples of boys and girls with and without ADHD a laboratory measure of childhood covert ASB prospectively predicted adolescent delinquency severity 4–5 years later controlling for initial ADHD overt aggression and noncompliance Lee and Hinshaw 2004 2006 A recent metaanalysis also suggests that genetic influences are substantially stronger for overt ASB than for covert ASB Burt 2009ASB also shows divergent patterns of association based on its age of onset Moffitt 1993 proposed two distinct types of antisocial youth lifecoursepersistent LCP and adolescentlimited AL The LCP pathway is significantly heritable frequently comorbid with ADHD and correlated with physical aggression neuropsychological deficits and parent psychopathology Aguilar et al 2000 Moffitt and Caspi 2001 There is also evidence that LCP children have higher levels of callous and unemotional traits eg low guilt lack of empathy less sensitive to punishment which is also predictive of aggression and delinquency Frick et al 2003 In contrast the AL pathway is associated with a postpubertal onset of ASB desistance by late adolescence relatively few child and family risk factors and a predominance of nonaggressive offending eg status offenses This pathway is driven predominantly by social processes eg deviant peer influences and personality factors eg sensation seeking Moffitt 1993 Evidence of a third subtype of ASB has also emerged Moffitt et al 2008 Compared to LCP and AL youth Odgers et al 2008 found that the childhoodlimited group had more child conduct problems but that these behaviors declined by midadolescence The prognosis for this group is poorly understood however Odgers et al 2007Although some theories of ASB converge with patterns of ASB observed in girls Keenan et al 1999 most studies have focused on boys Lahey et al 1999 despite important sex differences Loeber and StouthamerLoeber 1998 Silverthorn and Frick 1999 For example girls are less physically aggressive than boys Silverthorn and Frick 1999 and CD is two to fourtimes more common in boys than in girls Cohen et al 1993 However sex differences in ASB narrow significantly by early adolescence with girls whose ASB begins in adolescence showing worse outcomes than boys with a similar onset Fergusson et al 2005 This convergence is largely explained by girls engaging in nonaggressive ASB including relational ASB ie spreading rumors gossip ostracizing peers that are comparable to boys For example in the Dunedin birth cohort rates of nonaggressive ASB were equivalent in boys and girls at age 15 but boys were 3–4 times more physically aggressive than girls Moffitt et al 2001 In another study of 13000 5–11 yearold children girls and boys were equal in physical aggression at age 5 but by age 11 female aggression decreased whereas aggression in boys remained stable Lee et al 2007 Hipwell et al 2002 found that older girls showed higher rates of oppositional/defiant behaviors and relational aggression than younger girls in a community sample of 2451 girls aged 5 to 8 suggesting that nonaggressive ASB increases with age in girls Overall the literature suggests that age of onset and the type of ASB are central to understanding ASB across developmentEmpiricallyderived approaches that identify subgroups of antisocial youth are heuristic for several reasons including the value of personcentered strategies Bergman and Magnusson 1997 Taxonomies traditionally assume homogeneity within a group although thresholds may be arbitrary or inaccurate Schwartz et al 2001 For example children who fall just short of diagnostic criteria for CD and ODD are equally impaired as children who meet full criteria Levin 2008 Similarly frequent comorbidity challenges the assumption of homogeneity within a single disorder as evidenced by the fact that adolescents with CD frequently have comorbid ADHD anxiety and substance disorders Loeber and Keenan 1994 Compared to singledisorder and nondisordered cases individuals with comorbidity have worse health outcomes are more treatment resistant and more functionally impaired Newman et al 1998 Thus singledisorder contrasts eg CD vs controls may exaggerate effect sizes because of high comorbidity and they may arbitrarily define groups based on theory and clinical observation However empiricallydriven approaches have identified groups based on ASB severity and clinical presentation that are not reflected in current diagnostic approaches Lee et al 2007 De Nijs et al 2007 Reinke et al 2008To complement traditional groupbased approaches latent class analysis LCA creates a taxonomy based on similar patterns of responses McCutcheon 1987 Individuals within the same latent class are homogenous and distinct from other classes provided the indicator variables are locally independent Magidson and Vermunt 2004 LCA is a relatively anonymous approach where the number of classes is determined through an iterative process where the best fitting model determines the number of independent classes Magidson and Vermunt 2004 LCA is a more “personcentered” approach where groups of individuals are prioritized rather than traditional approaches that prioritize variablecentered models eg regression In addition LCA allows modeling predictors of class membership and the use of covariates Walrath et al 2004 Despite these benefits there are few published LCA studies of ASB De Nijs et al 2007 conducted LCA of the Attention Problems Aggression and RuleBreaking Behaviors scales of the Child Behavior Checklist on 1965 11 to 18yearold boys and girls referred to university clinics and mental health agencies Six distinct classes emerged with support for ADHD subtypes but not for separate aggressive or rulebreaking subtypes The failure to identify distinct aggressive and rulebreaking dimensions may have been due to referral bias eg clinicreferred youth have an earlier age of onset of problems more severe psychopathology and impairment that ultimately obscured these two classes Goodman et al 1997 Reinke et al 2008 utilized LCA with 678 lowincome AfricanAmerican children and found that boys were best characterized by 4 unique classes Academic Problems Behavior Problems Academic and Behavior Problems and No Problems Girls were similarly characterized only without the Behavior Problems group Girls and boys in the combined group of academic and behavior problems had significantly higher rates of social impairment suggesting that the groups derived demonstrated expected patterns of association with other domains However none of these studies tested specific predictors of group membership

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