L. John Horwood

Does father absence place daughters at special risk for early sexual activity and teenage pregnancy

The impact of father absence on early sexual activity and teenage pregnancy was investigated in longitudinal studies in the United States (N = 242) and New Zealand (N = 520), in which community samples of girls were followed prospectively from early in life (5 years) to approximately age 18. Greater exposure to father absence was strongly associated with elevated risk for early sexual activity and adolescent pregnancy. This elevated risk was either not explained (in the US. study) or only partly explained (in the New Zealand study) by familial, ecological, and personal disadvantages associated with father absence. After controlling for covariates, there was stronger and more consistent evidence of effects of father absence on early sexual activity and teenage pregnancy than on other behavioral or mental health problems or academic achievement. Effects of father absence are discussed in terms of life-course adversity, evolutionary psychology, social learning, and behavior genetic models.

The effect of maternal depression on maternal ratings of child behavior

There have been continuing concerns about the extent to which maternal depression may influence maternal reports of child behavior. To examine this issue, a series of structural equation models of the relationships between maternal depression and errors in maternal reports of child behavior was proposed and tested. These models assumed that (a) maternal depression was unrelated to maternal reporting behavior; (b) maternal depression causally influenced maternal reporting accuracy; (c) maternal depression was correlated with reporting accuracy. These models were fitted to data on maternal depression and multipleinformant (mother, teacher, child) reports of conduct disorder and attention deficit behaviors for a birth cohort of 12 and 13yearold New Zealand children. The results of model fitting suggested the presence of small to moderate correlations (@#@ r=+.13 to+.40) between maternal depression and maternal reporting errors, indicating the presence of a tendency for increasing maternal depression to be associated with a tendency for mothers to overreport child behavior problems. However, independently of any effects of maternal depression on maternal reporting errors there was evidence of small but significant associations (r=.10 to .17; p<.05)between maternal depression and child conduct disorder and attention deficit behaviors.

Predictive validity of categorically and dimensionally scored measures of disruptive childhood behaviors.

OBJECTIVE To examine the predictive validity of categorical and dimensional methods of representing variation in disruptive childhood behaviors. METHOD A birth cohort comprising 935 New Zealand children was assessed at age 15 years on measures based on DSM-III-R diagnostic criteria for oppositional defiant disorder, conduct disorder, and attention-deficit hyperactivity disorder. These symptom measures were scored in two ways: (1) as cases or noncases using DSM-III-R diagnostic criteria and (2) as dimensional variables in which the severity of disturbance ranged from none to severe. At age 16 years the cohort was reassessed on a series of measures including substance use behaviors, juvenile offending, and school dropout. RESULTS The analysis compared the efficacy of the categorically and dimensionally scored measures at age 15 years as predictors of outcomes observed at age 16 years. This comparison showed evidence of continuous and generally linear dose-response functions between symptom severity and outcome risks and that dimensionally scored variables were considerably better predictors of outcome than measures based on a diagnostic classification. CONCLUSIONS These findings support the view that disruptive behavior problems have dimensional properties in which the severity of disturbance ranges from none to severe. While DSM-III-R diagnostic criteria may have considerable value and utility as a means of diagnosing in young people behavior disturbances that merit clinical attention, the routine use of these criteria as a means of describing behavioral variability may result in a system of measurement that produces variables that have less than optimal predictive validity.

Asthma and depressive and anxiety disorders among young persons in the community.

BACKGROUND The objectives of the study were to examine linkages between asthma and depressive and anxiety disorders in a birth cohort of over 1000 young persons studied to the age of 21 years. Specifically, the study aimed to ascertain the extent to which associations between asthma and depressive and anxiety disorders could be explained by non-observed fixed confounding factors. METHOD Asthma and depressive and anxiety disorders were measured prospectively over the course of a 21-year longitudinal study. Fixed effects logistic regression models were used to determine the relationship between asthma and depressive and anxiety disorders, adjusting for potentially confounding factors. RESULTS Asthma in adolescence and young adulthood was associated with increased likelihood of major depression (OR 1.7, 95 % CI 1.3-2.3), panic attacks (OR 1.9, 95 % CI 1.3-2.8), and any anxiety disorder (OR 1.6, 95% CI 1.2-2.2). Associations between asthma and depressive and anxiety disorders were adjusted for confounding factors using a fixed effects regression model which showed that, after control for fixed confounding factors, asthma was no longer significantly related to major depression (OR 1.1), panic attacks (OR 1.1), or any anxiety disorder (OR 1.2). Additional post hoc analyses suggested that exposure to childhood adversity or unexamined familial factors may account for some of the co-morbidity of asthma and depressive and anxiety disorders. CONCLUSIONS These results confirm and extend previous findings by documenting elevated rates of depressive and anxiety disorders among young adults with asthma, compared with their counterparts without asthma, in the community. The weight of the evidence from this study suggests that associations between asthma and depressive and anxiety symptoms may reflect effects of common factors associated with both asthma and depressive and anxiety disorders, rather than a direct causal link. Future research is needed to identify the specific factors underlying these associations.

Maternal use of cannabis and pregnancy outcome

Objective To document the prevalence of cannabis use in a large sample of British women studied during pregnancy, to determine the association between cannabis use and social and lifestyle factors and assess any independent effects on pregnancy outcome.

Parental Separation, Adolescent Psychopathology, and Problem Behaviors

OBJECTIVE This paper examines the effects of parental separation on the occurrence of adolescent psychopathology and problem behaviors at age 15 years. METHODS Data collected during the course of a 15-year longitudinal study were used to examine a sample of 935 children with respect to exposure to parental separation during childhood, measures of adolescent psychopathology and problem behaviors at age 15 years, and prospectively collected confounding factors. RESULTS Children exposed to parental separation during childhood had elevated risks of a range of adolescent problems, including substance abuse or dependence, conduct or oppositional disorders, mood and anxiety disorders, and early-onset sexual activity. However, adjustment for confounding factors explained a large amount of the increased risks of adolescent disorder, and after adjustment for confounders the odds ratios between exposure to parental separation and adolescent outcomes ranged from 1.07 to 3.32 with a median value of 1.46. The ways in which boys and girls responded to parental separation were similar. CONCLUSIONS While the results suggested that children exposed to parental separation had increased risks of adolescent problems, much of this association appeared to be spurious and arose from confounding social and contextual factors that were present in the childs family before parental separation. However, even after such control, the results suggested that exposure to parental separation during childhood was associated with small but detectable increases in risks of adolescent conduct disorder, mood disorder, and substance abuse disorders.

Resilience and Vulnerability: Resilience to Childhood Adversity: Results of a 21-Year Study

INTRODUCTION There has been a large amount of research on the contributions of childhood and familial factors to the development of psychopathology in children and young people (for reviews see, e.g., Farrington et al., 1990; Hawkins, Catalano, & Miller, 1992; Loeber, 1990; Patterson, DeBaryshe, & Ramsey, 1989; Rutter & Giller, 1983). This research has established that young people reared in disadvantaged, dysfunctional, or impaired home environments have increased risks of a wide range of adverse outcomes that span mental health problems, criminality, substance abuse, suicidal behaviors, and educational underachievement. Although popular and policy concerns have often focused on the role of specific factors such as child abuse, poverty, single parenthood, family violence, parental divorce, and the like, the weight of the evidence suggests that the effects of specific risk factors in isolation on later outcomes often tend to be modest (Fergusson, Horwood, & Lynskey, 1994; Garmezy, 1987; Rutter, 1979; Sameroff, Seifer, Barocas, Zax, & Greenspan, 1987). What distinguishes the high-risk child from other children is not so much exposure to a specific risk factor but rather a life history characterized by multiple familial disadvantages that span social and economic disadvantages; impaired parenting; a neglectful and abusive home environment; marital conflict; family instability; family violence; and high exposure to adverse family life events (Blanz, Schmidt, & Esser, 1991; Fergusson et al., 1994; Masten, Morison, Pellegrini, & Tellegen, 1990; Sameroff & Seifer, 1990; Shaw & Emery, 1988; Shaw, Vondra, Hommerding, Keenan, & Dunn, 1994).

Origins of Comorbidity between Conduct and Affective Disorders

OBJECTIVE This analysis used methods of structural equation modeling to assess the extent to which comorbidity between conduct and affective disorders could be explained by (1) common or correlated causal factors that influenced both outcomes or (2) reciprocal causation between these conditions. METHOD Data were obtained during the course of a 16-year longitudinal study of a birth cohort of New Zealand children. The data analyzed comprised measures of conduct and affective disorders at ages 15 and 16 years and data on a series of antecedent childhood factors. RESULTS Structural equation modeling suggested that a substantial component of the comorbidity between conduct and affective disorders arose because the risk factors associated with the development of conduct disorders in teenagers overlapped and were correlated with the risk factors for adolescent affective disorders; of the shared variance between conduct disorder and affective disorders, more than two thirds was explained by common risk factors. These conclusions were replicated using diagnostically scored measures and methods of categorical data analysis. Model extensions suggested an absence of direct causal pathways between conduct and affective disorders. CONCLUSIONS A substantial amount of the correlation and comorbidity between conduct and affective disorders arises because the risk factors and life pathways that predispose adolescents to one outcome are also associated with the risk factors and life pathways that predispose adolescents to the other outcome. Nonetheless, even after control for common causal factors, there was evidence of some unexplained comorbidity between conduct and affective disorders.

Structure of DSM-III-R Criteria for Disruptive Childhood Behaviors: Confirmatory Factor Models

OBJECTIVE The aims of this analysis were to examine the extent to which DSM-III-R criteria for disruptive behavior patterns were consistent with the system of diagnoses proposed. Particular attention was paid to (1) whether oppositional defiant disorder is factorially distinct from conduct disorder (CD) and (2) the extent to which CD can be further classified into overt and covert CD behaviors. METHOD Data were gathered on DSM-III-R criteria for disruptive behavior patterns for a sample of 739 New Zealand 15-year-olds using data provided by parental and self-report. These data were supplemented by officially recorded police contact data. RESULTS Application of methods of confirmatory factor analysis suggested that the diagnostic criteria in DSM-III-R reflected a constellation of distinct but highly correlated behavioral domains, with these domains corresponding to oppositional defiant disorder, overt CD (aggression, violence), covert CD (theft, dishonesty), and attention-deficit hyperactivity disorder behavior. Results of second-order factor analysis methods suggested that these dimensions reflected two general higher-order factors, with the first factor reflecting the extent to which the individual displayed behavioral symptoms of oppositional defiant disorder and attention-deficit hyperactivity disorder and the second reflecting the extent to which the individual expressed antisocial, conduct-disordered behaviors. CONCLUSIONS The results of confirmatory factor analysis generally support and validate the diagnostic classifications proposed in DSM-III-R but suggest possible refinements that draw distinctions between overt and covert expressions of CD.

Illicit drug use and dependence in a New Zealand birth cohort

OBJECTIVE To describe the patterns of illicit drug use in a birth cohort studied to the age of 25 years. METHOD The data were gathered during the Christchurch Health and Development Study. In this study a cohort of 1265 children born in the Christchurch, New Zealand urban region in mid-1977 have been studied to the age of 25 years. Information was gathered on patterns of illicit drug use and dependence during the period 15-25 years. RESULTS By age 25 years, 76.7% of the cohort had used cannabis, while 43.5% had used other illicit drugs on at least one occasion. In addition, 12.5% of the cohort met DSM-IV criteria for dependence on cannabis, and 3.6% of the cohort met criteria for dependence on other illicit drugs at some time by age 25. There was also evidence of substantial poly-drug use among the cohort, with hallucinogens and amphetamines being the most commonly used illicit drugs (excluding cannabis). Illicit drug use and dependence was higher in males, in Māori, and in those leaving school without qualifications. Key risk factors for illicit drug use and dependence included adolescent risk-taking behaviours including cigarette smoking and alcohol consumption, affiliation with substance-using peers, novelty-seeking, and conduct problems in adolescence. Other key risk factors included parental history of illicit drug use and childhood sexual abuse. CONCLUSIONS Levels of cumulative illicit drug use in this cohort were relatively high, with the majority of respondents having tried illicit drugs by age 25. For the majority of illicit drug users, drug use did not lead to problems of dependence. Nonetheless, nearly 15% of the cohort showed symptoms of illicit drug dependence by the age of 25 years, with cannabis dependence accounting for the majority of illicit drug dependence.