Continuity of cannabis use and violent offending over the life course.

BACKGROUND: Although the association between cannabis use and violence has been reported in the literature, the precise nature of this relationship, especially the directionality of the association, is unclear. METHOD: Young males from the Cambridge Study of Delinquent Development (n = 411) were followed up between the ages of 8 and 56 years to prospectively investigate the association between cannabis use and violence. A multi-wave (eight assessments, T1-T8) follow-up design was employed that allowed temporal sequencing of the variables of interest and the analysis of violent outcome measures obtained from two sources: (i) criminal records (violent conviction); and (ii) self-reports. A combination of analytic approaches allowing inferences as to the directionality of associations was employed, including multivariate logistic regression analysis, fixed-effects analysis and cross-lagged modelling. RESULTS: Multivariable logistic regression revealed that compared with never-users, continued exposure to cannabis (use at age 18, 32 and 48 years) was associated with a higher risk of subsequent violent behaviour, as indexed by convictions [odds ratio (OR) 7.1, 95% confidence interval (CI) 2.19-23.59] or self-reports (OR 8.9, 95% CI 2.37-46.21). This effect persisted after controlling for other putative risk factors for violence. In predicting violence, fixed-effects analysis and cross-lagged modelling further indicated that this effect could not be explained by other unobserved time-invariant factors. Furthermore, these analyses uncovered a bi-directional relationship between cannabis use and violence. CONCLUSIONS: Together, these results provide strong indication that cannabis use predicts subsequent violent offending, suggesting a possible causal effect, and provide empirical evidence that may have implications for public policy.

Childhood Predictors and Adult Life Success of Adolescent Delinquency Abstainers.

While much is known about adolescent delinquency, considerably less attention has been given to adolescent delinquency abstention. Understanding how or why some adolescents manage to abstain from delinquency during adolescence is informative for understanding and preventing adolescent (minor) delinquency. Using data from the Cambridge Study in Delinquent Development (N = 411 males) to compare abstainers, self-report delinquents and convicted delinquents we found five childhood factors (ages 8-10) that predicted adolescent abstention (ages 10-18). First, we find that adolescent abstainers possess characteristics opposite to those of convicted delinquents (namely, abstainers are high on honesty, conformity and family income). However, we also found that abstainers also share some childhood characteristics with convicted delinquents (namely, low popularity and low school achievement). A latent class analysis indicated that the mixed factors predicting abstention can be accounted for by two groups of abstainers: an adaptive group characterized by high honesty, and a maladaptive group characterized by low popularity and low school achievement. Further, validation of these two types of abstainers using data collected at age 48 suggested that adaptive abstainers outperform all other adolescents in general life success, whereas maladaptive abstainers only fare better than delinquent adolescents in terms of lower substance use and delinquency later in life.

Cohort differences in the progression of developmental pathways: evidence for period effects on secular trends of violence in males.

BACKGROUND: Rates of violence in the USA have fluctuated widely over the past few decades. Theorists have examined period and cohort effects, but there appear to be no studies examining these effects on progression in developmental pathways towards violence. OBJECTIVE: To assess whether differences in progression among individuals in the Pittsburgh Youth Study are consistent with period or cohort effects. DESIGN: Multivariate logistic regression was conducted to examine differences between cohorts in the odds of progressing through the developmental pathway towards violence. Adjusted and unadjusted odds ratios (ORs) and corresponding 95% CI are reported. SETTING: Pittsburgh Pennsylvania, from 1987 to 2000. SUBJECTS: Two cohorts of male adolescents from the Pittsburgh Youth Study. The youngest cohort (n = 503) was followed from median ages 7 to 20, and the oldest cohort (n = 506) was followed up from median ages 13 to 25. MAIN OUTCOME MEASURE: The odds of progression along a developmental pathway towards violence. RESULTS: There was no statistically significant difference between the cohorts in progression from minor aggression to physical fighting (OR = 1.13, 95% CI 0.77 to 1.65). However, after adjustment for major risk factors, the oldest cohort was significantly more likely to progress from physical fighting to violence (OR = 2.34, 95% CI 1.39 to 3.92). CONCLUSIONS: These results provide initial evidence that cohort effects, which would be present early in development, do not contribute significantly to later differences in reported violence and raises the possibility of whether period effects can explain these differences.

The concentration of offenders in families, and family criminality in the prediction of boys' delinquency.

The main aims of this study were to investigate inter-relationships among offending by three generations of relatives (fathers, mothers, sons, daughters, uncles, aunts, grandfathers and grandmothers) and the concentration of offending in families. This study also investigates how far criminal relatives predict a boy's delinquency. The parents of 1395 Pittsburgh boys aged 8, 11 or 14 reported arrests by all relatives. Parent reports of boys' arrests predicted their later referrals to juvenile court, demonstrating predictive validity. Offenders were highly concentrated in families; if one relative had been arrested, there was a high likelihood that another relative had also been arrested. Arrests of relatives were compared with arrests of the boy, court petitions of the boy, and the boy's reported delinquency (according to the parent, boy and teacher). Arrests of brothers, sisters, fathers, mothers, uncles, aunts, grandfathers and grandmothers all predicted the boy's delinquency. The most important relative was the father; arrests of the father predicted the boy's delinquency independently of all other arrested relatives. Studies of explanatory variables suggested that having a young mother, living in a bad neighbourhood, and low guilt of the boy may be links in the causal chain between arrested fathers and delinquent boys.

Male mental health problems, psychopathy, and personality traits: key findings from the first 14 years of the Pittsburgh Youth Study.

This paper reviews key findings on juvenile mental health problems in boys, psychopathy, and personality traits, obtained in the first 14 years of studies using data from the Pittsburgh Youth Study. This is a study of 3 samples, each of about 500 boys initially randomly drawn from boys in the 1st, 4th, and 7th grades of public schools in Pittsburgh. The boys have been followed regularly, initially each half year, and later at yearly intervals. Currently, the oldest boys are about 25 years old, whereas the youngest boys are about 19. Findings are presented on the prevalence and interrelation of disruptive behaviors, ADHD, and depressed mood. Results concerning risk factors for these outcomes are reviewed. Psychological factors such as psychopathy, impulsivity, and personality are described. The paper closes with findings on service delivery of boys with mental health problems.

Psychosocial predictors of adult antisocial personality and adult convictions.

In the Cambridge Study in Delinquent Development, 411 South London males have been followed up since age 8. This article investigates the ability of psychosocial risk factors measured at age 8 - 10 to predict antisocial personality measures at ages 18 and 32 and convictions between ages 21 and 40. The most important childhood predictors were a convicted parent, large family size, low intelligence or attainment, and child-rearing factors, including a young mother and a disrupted family. The accuracy of prediction of antisocial personality at age 32 on the basis of childhood risk factors measured more than 20 years before was surprising: nearly half of boys with a convicted parent at age 10 were antisocial at age 32, compared with one in six of the remainder. Over 60% of boys very high risk at age 8 - 10 became antisocial at age 32. While the present research shows how far adult antisocial and criminal behavior can be predicted in childhood, more research is needed to establish the precise causal mechanisms involved.

Epidemiology of juvenile violence.

It is difficult to review the epidemiology of juvenile violence because few studies focus specifically on this topic as opposed to childhood aggression or delinquency in general. More research is needed specifically on juvenile violence, which is generally measured using official records or self-reports. Self-report research shows that a substantial fraction of the male juvenile population commits violence, and that very few violent acts are followed by arrests or convictions. Racial differences in violence may be explainable by reference to racial differences in community contexts. There is a great deal of versatility in juvenile violence. Juveniles who commit one type of violent offense also tend to commit other types and nonviolent offenses. Violent offenders tend to be persistent or frequent offenders, and there is little difference between violent offenders and nonviolent but equally frequent offenders. Nevertheless, there is some degree of specialization in violence. More research is needed to investigate whether risk factors exist for violence that are not risk factors for serious nonviolent delinquency (e.g., biologic factors). Violent juveniles tend to have co-occurring problems such as victimization, substance abuse, and school failure. Often, they might be described as multiple-problem youth. There is considerable continuity from childhood aggression to juvenile violence. An early age of onset of violence predicts a large number of violent offenses. The major long-term risk factors for juvenile violence are individual (high impulsiveness and low intelligence, possibly linked to the executive functions of the brain), family (poor supervision, harsh discipline, child physical abuse, a violent parent, large family size, poverty, a broken family), peer delinquency, gang membership, urban residence, and living in a high-crime neighborhood (characterized by gangs, guns, and drugs in the United States). More research is needed on interactions among risk factors, and especially on interactions between biologic and psychosocial risk factors. Important short-term situational factors include motives of potential offenders (e.g., anger, a desire to hurt), alcohol consumption, and actions leading to violent events (e.g., the escalation of a trivial altercation). More specific research is needed on protective factors against youth violence, for example, by investigating why aggressive children do not become violent juveniles. More research is also needed on the development and validation of risk assessment instruments. To investigate developmental and risk factors for juvenile violence, longitudinal studies are needed. Such studies should include multiple cohorts, to draw conclusions about different age groups, and should include both boys and girls and the major racial and ethnic groups. They should measure a wide range of risk and especially protective factors. They should be based on large, high-risk samples, especially in inner-city areas, incorporating screening methods to maximize the yield of violent offenders while simultaneously making it possible to draw conclusions about the total population. They should include long-term follow-up studies to permit conclusions about developmental pathways. They should make a special effort to study careers of violence and to link developmental and situational data. It will not be easy to mount new longitudinal studies focusing specifically on juvenile violence, but such studies are needed to advance knowledge about the epidemiology of juvenile violence, including risk factors and developmental pathways.

The OADP-CDS: a brief screener for adolescent conduct disorder.

OBJECTIVES: To examine the ability of a very brief (6-item) self-report screener, the Oregon Adolescent Depression Project Conduct Disorder Screener (OADP-CDS), to identify adolescents with a lifetime diagnosis of conduct disorder and to examine its ability to predict antisocial personality disorder by age 24. Relevant scales from the Yough Self-Report and the Child Behavior Checklist were examined for comparison purposes. METHOD: A total of 1,709 high school students completed an initial questionnaire and diagnostic interview assessment (T1); 1,507 participants returned approximately 1 year later for a second assessment (T2). A third (T3) assessment was conducted with selected T2 participants (n = 940) after they had turned 24 years of age. RESULTS: The OADP-CDS had good internal consistency, test-retest stability, and screening properties. Differences in the screening ability of the OADP-CDS as a function of gender and social desirability were nonsignificant. The efficacy of the measure as a screener did not differ significantly from that of longer adolescent- and parent-report measures. Perhaps most importantly, the OADP-CDS was able to identify future cases of antisocial personality disorder in young adulthood. CONCLUSIONS: Results suggest that self-report screening for conduct disorder with older adolescents is possible and should be explored further.

Young children who commit crime: epidemiology, developmental origins, risk factors, early interventions, and policy implications.

An early onset of delinquency prior to age 13 years increases the risk of later serious, violent, and chronic offending by a factor of 2-3. Also child delinquents, compared to juveniles who start offending at a later age, tend to have longer delinquent careers. This article summarizes the report of the Office of Juvenile Justice and Delinquency Prevention's Study Group on Very Young Offenders, chaired by Rolf Loeber and David P. Farrington. The Study Group, consisting of 16 scholars and 23 coauthors, worked for 2 years on preparing a report, undertaking extensive secondary data analyses, and writing chapters in different speciality areas. The report consists of a state of the art review of the developmental background of child delinquents. The report also summarizes risk and protective factors in the individual, family, peer group, school, and neighborhood that affect that development. Lastly, the report renews relevant preventive and remedial interventions in the juvenile justice system, families, peer groups, schools. and neighborhoods, and makes a case for improvement in the integration of services for child delinquents. Policy recommendations are presented to improve methods of dealing with child delinquents by juvenile justice, child welfare, and mental health agencies.

Boys who join gangs: a prospective study of predictors of first gang entry.

In a representative sample of boys who were in the 7th grade of an urban public school system at the start of a 6-year longitudinal study, more African American boys (23.8%) than non-Hispanic White boys (3.9%) had entered an antisocial gang by age 19. There were too few White gang members to study, but among African American boys, first gang entry was predicted prospectively by both baseline conduct disorder (CD) behaviors and increasing levels of CD behaviors prior to gang entry. This suggests that gang entry may be a further developmental step for some boys who are already on a trajectory of worsening antisocial behavior. Having friends prior to gang entry who engaged in aggressive delinquency increased the risk of gang entry further, but only during early adolescence. Family income and parental supervision also independently predicted gang entry, but the direction of their influences depended on the youth's age.

Brief report: types of bullying among Italian school children.

The main aim of this research was to investigate the prevalence of bullies and victims and the types and places of bullying. A questionnaire on bullying was completed by 113 girls and 125 boys in a middle school in Rome (aged 11-14 years). Over half of all students had bullied others in the previous 3 months, and nearly half had been bullied. Boys bullied more than girls, and both boys and girls tended to be bullied by boys. Boys were more likely to suffer direct bullying such as being threatened or physically hurt. Most of the bullying took place in the classroom; boys were likely to be bullied in the toilet.

Gun injury and mortality: the delinquent backgrounds of juvenile victims.

Serious injuries and deaths of three samples of boys were examined in an inner-city, longitudinal study. By age 19, almost 1 in 10 of the 506 participants in the oldest sample had been seriously wounded or killed. Two thirds of this group had been either wounded or killed by guns. Victims, compared to controls, tended to have a history of engaging in serious delinquency, gang fights, and selling drugs. They also tended to carry guns. The delinquent lifestyle of the victims was also evident from their court records. Victims tended to do poorly academically in school, received poorer parental supervision, had poorer communication with their parents, and had a long history of behavior problems.

Developmental associations between substance use and violence.

This study examined the developmental associations between substance use and violence. We examined the trends in each behavior throughout adolescence, how the behaviors covaried over time, and the symmetry of associations taking into account frequency and severity of each behavior. We also examined whether changes in one behavior affected changes in the other behavior over time. Six years of annual data were analyzed for 506 boys who were in the seventh grade at the first assessment. Concurrent associations between frequency of substance use and violence were relatively strong throughout adolescence and were somewhat stronger for marijuana than alcohol, especially in early adolescence. Type or severity of violence was not related to concurrent alcohol or marijuana frequency, but severity of drug use was related to concurrent violence frequency. Depending, to some degree, on the age of the subjects, the longitudinal relationships between substance use and violence were reciprocal during adolescence and slightly stronger for alcohol and violence than for marijuana and violence. Further, increases in alcohol use were related to increases in violence: however, when early alcohol use was controlled, increases in marijuana use were not related to increases in violence. Only in early adolescence was the longitudinal relationship between marijuana use and later violence especially strong. The strength of the longitudinal associations between violence and substance use did not change when common risk factors for violence and substance use were controlled. Overall, the data lend more support for a reciprocal than for a unidirectional association between substance use and violence. Prevention efforts should be directed at aggressive males who are multiple-substance users in early adolescence.

Fearlessness, stimulation-seeking, and large body size at age 3 years as early predispositions to childhood aggression at age 11 years.

BACKGROUND: Previous cross-sectional research in Western societies has linked adolescent stimulation-seeking, fearlessness, and body size to antisocial behavior. However, it is unclear how early in life these factors exert their influence, and nothing is known about their specificity to aggressive behavior per se. This study tests the hypotheses that stimulation-seeking, fearlessness, and increased body size at age 3 years predict aggression at age 11 years. METHODS: Behavioral measures of stimulation-seeking and fearlessness, together with height and weight, were measured at age 3 years and related to ratings of aggression at age 11 years in 1130 male and female Indian and Creole children from the island of Mauritius. RESULTS: Aggressive children at age 11 years were characterized by increased measures of stimulation-seeking, fearlessness, height, and weight at age 3 years. Stimulation-seeking and height were independently related to aggression, whereas the fearlessness-aggression relationship was mediated by height. Large body size at age 3 years but not 11 years was related to increased aggression at age 11 years, indicating a critical period in development for the influence of body size on aggression. CONCLUSIONS: Results (1) implicate large body size, stimulation-seeking, and fearlessness in the development of childhood aggression; (2) suggest that there may be a critical period in development in which biological processes influence later aggression; and (3) highlight the importance of early processes in the etiology of aggression.

Victim as offender in youth violence.

STUDY OBJECTIVE: To determine how often adolescent and young adult victims of assaultive injury are offenders in assaults and other crimes. DESIGN: Comparison of 10- to 24-year-old males treated in the accident and emergency department for assault-related injuries to similar-aged males treated in the same department for unintentional injuries. Police records were searched on both groups for warnings or convictions. SETTING: Accident and emergency department of the Cardiff Royal Infirmary. RESULTS: Assault patients were significantly more likely to be formally warned or convicted, and they had a higher mean number of warnings or convictions per 100 person-years of exposure, than other injury patients. These differences were most pronounced for the younger patients and for the year following the injury. CONCLUSION: These results suggest that many young male assault patients either have a history of criminal activity or develop criminal behavior subsequent to their assault and may benefit from appropriate intervention aimed at interrupting the cycle of crime and violence.

The Twelfth Jack Tizard Memorial Lecture. The development of offending and antisocial behaviour from childhood: key findings from the Cambridge Study in Delinquent Development.

In the Cambridge Study in Delinquent Development, 411 South London males have been followed up from age 8 to age 32. The most important childhood (age 8-10) predictors of delinquency were antisocial child behaviour, impulsivity, low intelligence and attainment, family criminality, poverty and poor parental child-rearing behaviour. Offending was only one element of a larger syndrome of antisocial behaviour that arose in childhood and persisted into adulthood. Marriage, employment and moving out of London fostered desistance from offending. Early prevention experiments are needed to reduce delinquency, targeting low attainment, poor parenting, impulsivity and poverty.

Prevention of violence. Role of the pediatrician.

The pervasiveness of delinquency and violence in our society and the impact on morbidity and mortality have made violence a major public health issue. There is a general continuity of antisocial behavior from early childhood to adolescence and adulthood. Important risk factors for delinquency and violence are poor parenting, untreated conduct disorder, social stress, poverty, and school failure. Pediatricians can play a major role in violence prevention through recognition of and intervention for poor parenting, provision of social support to families, recognition and management of behavior problems, and promotion of preschool and early childhood education programs. Such interventions are likely to have a far greater impact on delinquency and violence than secondary and tertiary prevention programs such as those of the criminal justice system.