Prenatal tobacco exposure and the risk of conduct disorder symptoms in offspring at the age of 14 years: Findings from the Raine Study.

BACKGROUND: Emerging epidemiological evidence suggests that offspring born to mothers who smoked tobacco during pregnancy may have elevated risk of developing conduct disorder (CD) symptoms. We examined associations between maternal and paternal tobacco smoking during pregnancy and CD symptoms in offspring at the age of 14 years. METHODS: We obtained data from the Raine Study, a multi-generational cohort study based in Western Australia. DSM-oriented scale of the Child Behavior Checklist (CBCL) was used to measure CD symptoms in offspring. Negative binomial regression was used to estimate the rate ratio (risks) (RR) of CD symptoms in offspring. We also produced the E-values to investigate the extent of unmeasured confounding. Paternal smoking during pregnancy was used as a proxy for environmental tobacco smoke exposure. RESULTS: Complete data were available for 1747 mother-offspring and 1711 father-offspring pairs. After adjusting for potential confounders, we found elevated risks (rates) of CD symptoms in offspring born to mothers smoking tobacco during the first trimester [RR 1.52 (95 % CI: 1.24-1.87)], third trimester [RR 1.36 (95 % CI: 1.09-1.69)] and during both trimesters of pregnancy [RR 1.50 (95 % CI: 1.19-1.90)]. The rates of CD symptoms in offspring increased with the level of exposure to maternal smoking during pregnancy. However, we noted insufficient statistical evidence for an association between paternal smoking during pregnancy and CD symptoms in offspring. CONCLUSION: The associations we found for maternal but not paternal smoking may suggest a biological mechanism for intrauterine tobacco exposure on the risk of CD symptoms in offspring. Early interventions assisting pregnant mothers to quit tobacco smoking, or avoid smoking initiation, have potential to contribute health benefits to both mothers and their offspring.

Aspectos antissociais na velhice / Les aspects anti-sociaux de la vieillesse / Aspectos antisociales en la vejez / Antissocial aspects in ageing

Resumos Segundo Winnicott, a tendência antissocial tem por etiologia uma deprivação que ocorre quando está se dando a fusão entre os elementos instintuais e motores. A desfusão desses elementos resulta num prejuízo no desenvolvimento criativo das relações objetais e na expressão da agressividade. A tendência antissocial se manifesta através de um transtorno no ambiente, por meio da mentira, do roubo e da destrutividade. Neste artigo, apresento um caso clínico em que surgiram comportamentos antissociais numa pessoa idosa e como se constituiu o setting terapêutico para seu tratamento. Por fim, o texto discute se a etapa da vida que se conhece por velhice, por se apresentar amiúde com decadência física e declínio instintual, não causaria nos indivíduos uma deprivação que se expressaria por meio de múltiplos transtornos, normalmente percebidos como manifestações da mera velhice e que, na verdade, poderiam ser mais bem entendidos como expressão de uma tendência antissocial.

Résumé Selon Winnicott, la tendance antisociale résulte d'une privation qui se produit au moment où s'opère la fusion entre les éléments instinctuels et moteurs. La défusion de ces éléments entraîne une perte dans le développement créatif des relations objectales et dans l'expression de l'agressivité. La tendance antisociale se manifeste par une perturbation de l'environnement, par le mensonge, le vol et la destruction. Cet article présente un cas clinique dans lequel des comportements antisociaux se sont apparu chez une personne âgée et comment s'est constitué le cadre thérapeutique de son traitement. Enfin, le texte propose une réflexion : cette étape de la vie, que l'on nomme vieillesse et qui se présente souvent comme une déchéance physique et un déclin instinctif, ne provoquerait-elle chez les individus une déprivation qui s'exprimerait par de multiples troubles, normalement perçus comme des manifestations de la simple vieillesse mais qui, en fait, pourraient être mieux compris comme l'expression d'une tendance antisociale ?

Resumen Según Winnicott, la tendencia antisocial tiene por etiología una deprivación, que ocurre cuando los elementos instintuales y motores se están fusionando. La escisión entre estos elementos tiene como resultado un perjuicio en el desarrollo creativo de las relaciones objetales y la expresión de agresividad. La tendencia antisocial se manifiesta como una perturbación en el entorno mediante la mentira, el robo y la destructividad. En este artículo se presenta un caso clínico en el que surgieron comportamientos antisociales en una persona mayor y cómo se constituyó el setting terapéutico. Por último, se discute si la etapa de la vida conocida como vejez, por su decadencia física y el deterioro instintual en general, no les causaría a los individuos una deprivación, la cual se expresaría en múltiples desórdenes de la vejez que podrían entenderse como la expresión de una tendencia antisocial.

Abstract According to Winnicott, antisocial tendency etiology is an experience of deprivation that occurs during the fusion between instinctual and motor elements. These elements defusion impairs creative development of object relations and leads to an expression of aggression. In this scenario, the antisocial tendency is expressed by an environmental disorder, through lies, stealing, and destructivity. This article presents a clinical case of antisocial behaviors in an older person, describing the therapeutic setting for the treatment of such condition. Considering that ageing often presents with physical decadence and instinctual decline, it also discusses the association between this life period and a deprivation expressed through multiple disorders that are usually understood as signs of mere senescence but could possibly signify the expression of an antisocial tendency.

Developmental Trajectories of Conduct Problems and Cumulative Risk from Early Childhood to Adolescence.

Pathways into and out of conduct problems differ by circumstances experienced since infancy. There is a research gap in understanding how these developmental patterns vary according to the timing and persistence of risk and whether there are differences across ecological domains. This study examines variations in trajectories of conduct problems between ages 3 to 14 years and associated child, family and socio-economic risk factors from ages 9 months to 14 years, drawing on the UK Millennium Cohort Study (n = 17,206, 49% female), a nationally representative longitudinal study of children born between 2000/02. Group-based modeling was used to identify four distinct trajectories of conduct problems: low (56%), persistent high (8%), childhood-limited (23%) and adolescent-onset (13%). All three problem pathways were associated with high levels of exposure to risk, particularly early socio-economic and persisting child and family risks. However, while for the persistent and adolescent-onset pathways, exposure to higher levels of family and child risks continued through adolescence, it receded for the childhood-limited trajectory. The effects of early socio-economic disadvantage persisted for those on the adolescent-onset trajectory, highlighting the importance of early markers for this later onset group. Maternal smoking in pregnancy continued to be a significant predictor for all three conduct problem groups, even up to age 14 years. The findings indicate that different influences and processes may explain diverse pathways of conduct problems. This offers insights into who and what might be targeted and when might be the most effective developmental window for intervention.

Pregnancy risk factors in relation to oppositional-defiant and conduct disorder symptoms in the Avon Longitudinal Study of Parents and Children.

BACKGROUND: Pregnancy factors have been implicated in offspring oppositional-defiant disorder (ODD) and conduct disorder (CD) symptoms. Literature still holds notable limitations, such as studying only a restricted set of pregnancy factors, use of screening questionnaires which assess broadly defined outcome measures, and lack of control for disruptive behavior comorbidity and genetic confounds. We aimed to address these gaps by prospectively studying a broad range of pregnancy factors in relation to both offspring ODD and CD symptomatology in the Avon Longitudinal Study of Parent and Children. METHODS: Outcomes were ODD and CD symptom scores at age 7;9 years using the Development and Well-Being Assessment interview. We analyzed maternal (N ≈ 6300) and teacher ratings (N ≈ 4400) of ODD and CD scores separately using negative binomial regression in multivariable models. Control variables included comorbid attention-deficit/hyperactivity disorder symptoms, ODD or CD symptoms as appropriate, and genetic risk scores based on an independent CD genome-wide association study. RESULTS: Higher ODD symptom scores were linked to paracetamol use (IRR = 1.24 [98.3% confidence interval 1.05-1.47], P = 0.002, teacher ratings) and life events stress (IRR = 1.22 [1.07-1.39], P = 0.002, maternal ratings) during pregnancy. Higher CD symptom scores were linked to maternal smoking (IRR = 1.33 [1.18-1.51], P < 0.001, maternal ratings), life events stress (IRR = 1.24 [1.11-1.38], P < 0.001, maternal ratings) and depressive symptoms (IRR = 1.14 [1.01-1.30], P = 0.006, maternal ratings) during pregnancy. CONCLUSIONS: Common and potentially preventable pregnancy risk factors were independently related to both offspring ODD and CD symptomatology in children from the general population. Future studies should further address genetic confounds and confounding by environmental factors later in life.

Infant Iron Deficiency and Iron Supplementation Predict Adolescent Internalizing, Externalizing, and Social Problems.

OBJECTIVE: To evaluate associations between iron supplementation and iron deficiency in infancy and internalizing, externalizing, and social problems in adolescence. STUDY DESIGN: The study is a follow-up of infants as adolescents from working-class communities around Santiago, Chile who participated in a preventive trial of iron supplementation at 6 months of age. Inclusionary criteria included birth weight ≥3.0 kg, healthy singleton term birth, vaginal delivery, and a stable caregiver. Iron status was assessed at 12 and 18 months of age. At 11-17 years of age, internalizing, externalizing, and social problems were reported by 1018 adolescents with the Youth Self Report and by parents with the Child Behavior Checklist. RESULTS: Adolescents who received iron supplementation in infancy had greater self-reported attention-deficit/hyperactivity disorder but lower parent-reported conduct disorder symptoms than those who did not (Ps < .05). Iron deficiency with or without anemia at 12 or 18 months of age predicted greater adolescent behavior problems compared with iron sufficiency: more adolescent-reported anxiety and social problems, and parent-reported social, post-traumatic stress disorder, attention-deficit/hyperactivity disorder, oppositional defiant, conduct, aggression, and rule breaking problems (Ps < .05). The threshold was iron deficiency with or without anemia for each of these outcomes. CONCLUSIONS: Iron deficiency with or without anemia in infancy was associated with increased internalizing, externalizing, and social problems in adolescence.

Maternal substance use during pregnancy and offspring conduct problems: A meta-analysis.

We conducted meta-analyses of relationships between highly prevalent substance use during pregnancy and offspring conduct disorder problems. In total 36 studies were included. Odds ratios (ORs) were 2.06 (1.67-2.54, 25 studies) for maternal smoking, 2.11 (1.42-3.15, 9 studies) for alcohol use, and 1.29 (0.93-1.81, 3 studies) for cannabis use, while a single study of caffeine use reported no effects. Our meta-analyses support an association between smoking and alcohol use during pregnancy, and offspring conduct problems, yet do not resolve causality issues given potential confounding by genetic factors, gene-environment interactions, and comorbidity such as with attention deficit hyperactivity disorders. Future studies should use genetically sensitive designs to investigate the role of pregnancy substance use in offspring conduct problems and may consider more broadly defined behavioral problems.

The Association Between Prenatal Stress and Externalizing Symptoms in Childhood: Evidence From the Avon Longitudinal Study of Parents and Children.

BACKGROUND: It has been suggested that prenatal maternal stress may increase the risk of childhood externalizing disorders, yet no large cohort study has investigated this association across a large range of acute stressors. Our objective was to estimate the association between prenatal stressful events and risk of offspring conduct disorder and hyperactivity. METHODS: We used data from 10,184 mother-offspring pairs from the United Kingdom-based Avon Longitudinal Study of Parents and Children. Mothers self-reported 42 prenatal stressful life events at 18 weeks' gestation. Symptoms of conduct disorder and hyperactivity in their offspring were measured at 6, 9, 11, 13, and 16 years of age using the Strengths and Difficulties Questionnaire. The primary outcome was membership in high-symptom trajectories of 1) conduct disorder and 2) hyperactivity throughout childhood, identified using latent class growth modeling. Multinomial logistic regression models estimated the association between prenatal stress and both conduct disorder and hyperactivity, after adjusting for sex, parental education, low birth weight, preterm birth, parental social class, maternal smoking and drinking, maternal mental health, offspring stressful life events, and offspring depressive and anxious symptoms. RESULTS: Those exposed to the highest quartile of prenatal stress were more likely to belong to the high symptom trajectory for hyperactivity (B = 0.46, p < .05) and conduct disorder (B = 0.88, p < .01), respectively. Prenatal stress further demonstrated a positive, dose-response relationship with symptoms of externalizing disorders at independent time points. CONCLUSIONS: The findings suggest that prenatal stressful events may be an independent risk factor for offspring externalizing symptoms, regardless of maternal mental health and offspring internalizing.

[Pre- and perinatal risk factors in autism spectrum disorder and attention deficit/hyperactivity disorder]. / Prä- und perinatale Risikofaktoren bei Autismus-Spektrum-Störung und Aktivitäts- und Aufmerksamkeitsstörung.

Objective: Epidemiological studies indicate the relevance of pre- and perinatal risk factors for the genesis of attention deficit/hyperactivity disorder and autism spectrum disorder. This study compares potential risk factors in a clinical sample of children with ADHD, ASD, the combination of both diseases, ADHD and oppositional defiant or conduct disorder (ADHD & ODD/CD) and examined whether the existence of additional risk factors promotes the occurrence of combined diseases. Method: We compared the pre- and perinatal risk factors of 341 patients (299 boys, 42 girls) from a clinical population, differentiating between children with ADHD (n=80), ASD (n=122), ADHD & ASD (n=55), or ADHD & ODD/CD (n=84). Results: We observed a higher rate of maternal smoking, a higher rate of migration, and lower parental education among the children with ADHD & ODD/CD compared to those with ASD or ADHD. The rate of migration background was higher among the children with ASD compared to children with ADHD. Miscarriage was a specific risk factor for ADHD & ASD. Conclusion: Numerous risk factors described in epidemiological studies occurred only rarely in our clinical sample. The distribution of most risk factors was comparable between the examined diseases.

Dysfunctional family environments and childhood psychopathology: the role of psychiatric comorbidity / Ambientes de famílias disfuncionais e psicopatologia infantil: o papel da comorbidade psiquiátrica

Introduction: The study of the association between specific characteristics of family environments and different types of psychopathology may contribute to our understanding of these complex disorders and ultimately inform therapeutics. Objective: To compare the family characteristics of four groups: typically developing children; children with anxiety disorders only; children with externalizing disorders only; and children with both anxiety and externalizing disorders. Methods: This study enrolled 115 individuals from the community. Child psychiatrists made psychiatric diagnoses using a structured clinical interview. The Family Environment scale was used to evaluate six domains of family function. Results: The group with both anxiety and externalizing disorders had higher levels of conflict in family environment and lower levels of organization when compared with typically developing children. In addition, internalizing and externalizing symptoms were positively associated with conflict and negatively with organization. Maternal depressive and anxious symptoms were also associated with higher conflict and lower organization scores. Conclusion: An important between-group difference in comorbid cases of anxiety and behavioral disorders suggests that children with this comorbidity are potential candidates for family interventions to address family conflicts and organizational aspects (AU)

Introdução: O estudo da relação entre características específicas do ambiente familiar e os diferentes tipos de psicopatologias pode contribuir para o nosso entendimento desses complexos transtornos e possivelmente gerar informações para seu tratamento. Objetivo: Comparar as características familiares de quatro grupos: Crianças com desenvolvimento típico; crianças com transtornos de ansiedade apenas; crianças com transtornos de externalização apenas; e crianças com transtornos de ansiedade e de externalização. Métodos: Cento e quinze indivíduos foram recrutados na comunidade. Psiquiatras pediátricos usaram uma entrevista clínica estruturada para estabelecer os diagnósticos psiquiátricos. A Escala do Ambiente Familiar (Family Environment) foi usada para avaliar os seis domínios de funcionamento da família. Resultados: O grupo que apresentava tanto transtornos de ansiedade quanto de externalização apresentou níveis mais altos de conflito e níveis mais baixos de organização quando comparados com as crianças com desenvolvimento típico. Além disso, os sintomas de externalização e internalização estavam positivamente relacionados a conflitos e negativamente a organização. Sintomas depressivos e de ansiedade da mãe também se mostraram relacionados a resultados mais altos para conflito e mais baixos para organização. Conclusão: Uma importante diferença entre grupos em casos de comorbidades de transtornos de ansiedade e de comportamento sugerem que as crianças com esta comorbidades são candidatos em potencial para intervenções familiares que abordem conflitos familiares e aspectos organizacionais (AU)

Maternal smoking during pregnancy and offspring conduct problems: evidence from 3 independent genetically sensitive research designs.

IMPORTANCE: Several studies report an association between maternal smoking during pregnancy and offspring conduct disorder. However, past research evidences difficulty in disaggregating prenatal environmental influences from genetic and postnatal environmental influences. OBJECTIVE: To examine the relationship between maternal smoking during pregnancy and offspring conduct problems among children reared by genetically related mothers and genetically unrelated mothers. DESIGN, SETTING, AND PARTICIPANTS: The following 3 studies using distinct but complementary research designs were used: The Christchurch Health and Development Study (a longitudinal cohort study that includes biological and adopted children), the Early Growth and Development Study (a longitudinal adoption-at-birth study), and the Cardiff IVF (In Vitro Fertilization) Study (an adoption-at-conception study among genetically related families and genetically unrelated families). Maternal smoking during pregnancy was measured as the mean number of cigarettes per day (0, 1-9, or 10) smoked during pregnancy. Possible covariates were controlled for in the analyses, including child sex, birth weight, race/ethnicity, placement age, and breastfeeding, as well as maternal education and maternal age at birth and family breakdown, parenting practices, and family socioeconomic status. MAIN OUTCOMES AND MEASURE: Offspring conduct problems (age range, 4-10 years) reported by parents or teachers using the behavior rating scales by Rutter and Conners, the Child Behavior Checklist and the Children's Behavior Questionnaire Short Form, and the Strengths and Difficulties Questionnaire. RESULTS: A significant association between maternal smoking during pregnancy and offspring conduct problems was observed among children reared by genetically related mothers and genetically unrelated mothers. Results from a meta-analysis affirmed this pattern of findings across pooled study samples. CONCLUSIONS AND RELEVANCE: Findings across 3 studies using a complement of genetically sensitive research designs suggest that smoking during pregnancy is a prenatal risk factor for offspring conduct problems when controlling for specific perinatal and postnatal confounding factors.

Prospective associations between early long-term household tobacco smoke exposure and antisocial behaviour in later childhood.

BACKGROUND: Using a prospective birth cohort design, we estimate the relative contribution of long-term postnatal nicotine exposure from 17 to 86 months on children's subsequent antisocial behaviour by the end of fourth grade. METHOD: Parents reported the amount of household smoke exposure (at 17, 41, 65 and 86 months) for all 2055 children from the Quebec Longitudinal Study of Child Development. Main outcome measures include teacher- and child-reported antisocial and physically aggressive behaviour (at 121 months). RESULTS: In terms of prevalence, 58% of parents reported that their children were never exposed to secondhand smoke in the home, while 34% and 8% of parents reported transient and continuous levels of secondhand smoke, respectively. When compared with never exposed children, children exposed to continuous secondhand smoke scored higher on self-reported aggressive behaviour and teacher-rated antisocial behaviour in fourth grade, B=0.336 (95% CI 0.155 to 0.517) and B=0.319 (95% CI 0.107 to 0.531), respectively. Similarly, children exposed to transient levels of secondhand smoke scored higher on aggressive and antisocial behaviour, B=0.714 (95% CI 0.456 to 0.972) and B=0.566 (95% CI 0.260 to 0.872), respectively. CONCLUSIONS: The observed prevalence is concordant with worldwide estimates of children's exposure to secondhand smoke. In comparison with their never exposed peers, children continuously and intermittently exposed to secondhand smoke in childhood showed an increased propensity toward physical aggression and antisocial behaviour by the end of fourth grade. We found no evidence of dose-dependence.

From correlates to causes: can quasi-experimental studies and statistical innovations bring us closer to identifying the causes of antisocial behavior?

Longitudinal, epidemiological studies have identified robust risk factors for youth antisocial behavior, including harsh and coercive discipline, maltreatment, smoking during pregnancy, divorce, teen parenthood, peer deviance, parental psychopathology, and social disadvantage. Nevertheless, because this literature is largely based on observational studies, it remains unclear whether these risk factors have truly causal effects. Identifying causal risk factors for antisocial behavior would be informative for intervention efforts and for studies that test whether individuals are differentially susceptible to risk exposures. In this article, we identify the challenges to causal inference posed by observational studies and describe quasi-experimental methods and statistical innovations that may move researchers beyond discussions of risk factors to allow for stronger causal inference. We then review studies that used these methods, and we evaluate whether robust risk factors identified from observational studies are likely to play a causal role in the emergence and development of youth antisocial behavior. There is evidence of causal effects for most of the risk factors we review. However, these effects are typically smaller than those reported in observational studies, suggesting that familial confounding, social selection, and misidentification might also explain some of the association between risk exposures and antisocial behavior. For some risk factors (e.g., smoking during pregnancy, parent alcohol problems), the evidence is weak that they have environmentally mediated effects on youth antisocial behavior. We discuss the implications of these findings for intervention efforts to reduce antisocial behavior and for basic research on the etiology and course of antisocial behavior.

Risk factors for conduct disorder and oppositional/defiant disorder: evidence from a New Zealand birth cohort.

OBJECTIVE: To examine the social, family background, and individual antecedents of conduct disorder (CD) and oppositional defiant disorder (ODD), the extent to which CD and ODD symptoms were predicted by common environmental risk factors, and the extent to which the antecedents of CD and ODD accounted for the comorbidity between the two disorders. METHOD: Data were gathered from 926 members of a New Zealand longitudinal birth cohort. The outcome measures were DSM-IV symptom count measures of CD and ODD at age 14 to 16 years. Predictors measured during the period from 0 to 14 years included the following: maternal smoking during pregnancy; exposure to socioeconomic adversity; parental maladaptive behavior; childhood exposure to abuse and interparental violence; gender; cognitive ability; and affiliation with deviant peers in early adolescence. Associations between the predictors and outcome measures were modeled using structural equation modeling. RESULTS: The analyses showed that each of the predictors was significantly (p < .05) associated with CD and ODD, with the exception of gender and ODD. After model fitting, the profile of risk factors that predicted CD and ODD were largely similar. The analyses revealed that approximately 40% of the comorbidity between disorders could be accounted for by common factors. CONCLUSIONS: The data showed that CD and ODD had largely similar social and environmental antecedents. One implication of this finding is that treatment and prevention approaches that are developed for use with a particular behavior disorder may in fact reduce the incidence of both disorders.

Mothers' antenatal depression and their children's antisocial outcomes.

Interviews of 120 British adolescents and their parents (80% of a random sample of antenatal patients drawn from a representative urban population and followed longitudinally) revealed that 40 (33%) had been arrested and/or had a diagnosis of DSM-IV conduct disorder by 16 years of age; of those, 18 (45%) had committed violent acts. Depression in pregnancy significantly predicted violence in adolescence, even after controlling for the family environment, the child's later exposure to maternal depression, the mother's smoking and drinking during pregnancy, and parents' antisocial behavior. Mothers with a history of conduct problems were at elevated risk to become depressed in pregnancy, and the offspring of depressed women had a greater chance of becoming violent by age 16.

[Conduct disorders in seven-year-old children--results of ELSPAC study. 3. Postnatal development]. / Poruchy chování u sedmiletých detí-- výsledky studie ELSPAC. 3. Vývoj v období po narození.

BACKGROUND: In the European Longitudinal Study of Pregnancy and Childhood (ELSPAC), the pediatric observation of the cohort of 6100 7-year-old children described 4.4% of them as having conduct disorders. METHODS AND RESULTS: The predominant markers such as strong negativism, aggressivity, attention deficit, non-adequate reactions, hyperactivity, disorders of psychomotoric development, school maturation delay, poorer school results and social adaptation described children behavioral problems. The first signs of conduct disorders were often discovered already at the 18th month and the 3rd year of children's age. The acceptance of standardized criteria of possible conduct disorders in the routine pediatric practice, and the special psychologic and/or psychiatric care for children with the confirmed diagnosis should be recommended as soon as in their toddler age. CONCLUSIONS: Possible causal associations between prenatal exposure to nicotine and conduct disorders in childhood are another strong reason for the primary prevention and smoking cessation in antenatal clinics.

Parental smoking and adolescent problem behavior: an adoption study of general and specific effects.

OBJECTIVE: It is essential to understand the effect of parental smoking on offspring tobacco use. In biologically related families, parents who smoke may transmit a nonspecific genetic risk for offspring disinhibited behavior, including tobacco use. Studying adoptive families allows one to control for genetic confounding when examining the environmental effect of exposure to parental smoking. The purpose of this study was to examine the genetic and environmental contributions to the risk represented by exposure to parental smoking and to assess the specificity of that risk. METHODS: Adolescents adopted in infancy were systematically ascertained from records of three private Minnesota adoption agencies; nonadopted adolescents were ascertained from Minnesota birth records. Adolescents and their rearing parents participated in all assessments in person. The main outcome measures were self-reports of behavioral deviance, substance use, and personality, as well as DSM-IV clinical assessments of childhood disruptive disorders. RESULTS: The data from adoptive families suggest that exposure to parental smoking represents an environmental risk for substance use in adolescent offspring. In biologically related families, the effect of exposure to parental smoking is larger and more diverse, including substance use, disruptive behavior disorders, delinquency, deviant peer affiliations, aggressive attitudes, and preference for risk taking. CONCLUSIONS: This study provides evidence for an environmentally mediated pathway by which parental smoking increases risk specifically for substance use in adolescent offspring. The data are also consistent with a genetically mediated pathway by which nonadoptive parents who smoke may also transmit a nonspecific genetic risk to their offspring for disinhibited behavior.