Salivary cortisol and aggression in a population-based longitudinal study of adolescent males.

Chronic antisocial behaviour in youth has been associated with cortisol, a measure of stress reactivity. However, some studies have found low cortisol levels, while others have found elevated cortisol levels. The present study compared variously defined aggressive subgroups for differences in salivary cortisol. A population-based sample of boys was followed longitudinally from childhood to adolescence. Assessments of different forms of antisocial behaviour were obtained from various informants at several points in time, and cortisol was collected at age 13. Higher cortisol levels were found in boys with conduct disorder (CD) than in boys without CD. In addition, boys with an aggressive form of CD had higher cortisol levels than boys who showed a covert form of CD. Furthermore, reactive aggression was strongly correlated with elevated cortisol. Adolescent boys with chronic reactive aggression and those who scored high on aggressive CD symptoms seem to have a more active hypothalamic-pituitary-adrenal system.

Predicting girls' conduct disorder in adolescence from childhood trajectories of disruptive behaviors.

OBJECTIVE: To examine girls' developmental trajectories of disruptive behaviors during the elementary school years and to predict conduct disorder symptoms and diagnosis in adolescence with trajectories of these behaviors. METHOD: The sample was 820 girls from the province of Quebec followed over 10 years (1986-1996). A semiparametric mixture model was used to describe girls' developmental trajectories of teacher-rated disruptive behaviors between the ages of 6 and 12 years. The trajectories were used to predict conduct disorder symptoms and diagnosis when the girls were on average 15.7 years. RESULTS: Four groups of girls following trajectories with distinct levels of disruptive behaviors were identified: a low, medium, medium-high, and high trajectory. Prediction with the trajectories indicated that girls on the medium, medium-high, and high trajectories reported a significantly higher number of conduct disorder symptoms in adolescence. However, only the girls on the medium-high and high trajectories were at significantly higher risk to meet DSM-III-R criteria for conduct disorder, compared with girls in the low group (odds ratio: 4.46). More than two thirds of the girls with conduct disorder were in the medium or higher-level trajectories. CONCLUSION: The results suggest that there is an early-onset type of conduct disorder in girls.

Developmental trajectories of physical aggression from school entry to late adolescence.

The developmental perspective applied to psychopathology has led to the concept of early- and late-onset disorders. This study explores the application of the early- and late-onset concepts of antisocial behavior to physical aggression. Are there two categories of chronically physically violent adolescents: those who are physically aggressive throughout childhood and those who start being physically aggressive during adolescence? The estimation of developmental trajectories for repeated measures of two different response variables physical aggression in childhood as measured by teacher reports and physical aggression in adolescence as measured by self-reported violent delinquency is achieved with a semi-parametric, group-based method. This new method is applied to a large sample of males from Montreal who have been assessed repeatedly since kindergarten. Several salient findings emerge from the analysis. First, we find considerable change in the levels of childhood and adolescent physical aggression. Thus, there is little evidence of stability of behavior in an absolute sense. A second key finding concerns the connection of childhood aggression to adolescent aggression. Boys with higher childhood physical aggression trajectories are far more likely to transition to a higher-level adolescent aggression trajectory than boys from lower childhood physical aggression trajectories. However, for all childhood physical aggression trajectory levels the modal transition is to a relatively low-level adolescent aggression trajectory. Third, we find little evidence of "late onset" of high-level physical aggression. Specifically, the joint trajectory analysis finds no evidence of transition from a low physical aggression trajectory in childhood to a high trajectory in adolescence.

Analyzing developmental trajectories of distinct but related behaviors: a group-based method.

This article presents a group-based method to jointly estimate developmental trajectories of 2 distinct but theoretically related measurement series. The method will aid the analysis of comorbidity and heterotypic continuity. Three key outputs of the model are (a) for both measurement series, the form of the trajectory of distinctive subpopulations; (b) the probability of membership in each such trajectory group; and (c) the joint probability of membership in trajectory groups across behaviors. This final output offers 2 novel features. First, the joint probabilities can characterize the linkage in the developmental course of distinct but related behaviors. Second, the joint probabilities can measure differences within the population in the magnitude of this linkage. Two examples are presented to illustrate the application of the method.

Parental and early childhood predictors of persistent physical aggression in boys from kindergarten to high school.

BACKGROUND: In a prior study, we identified 4 groups following distinct developmental courses, or trajectories, of physical aggression in 1037 boys from 6 to 15 years of age in a high-risk population sample from Montréal, Québec. Two were trajectories of high aggression, a persistently high group and a high but declining group. The other 2 trajectories were a low group and a moderate declining group. This study identified early predictors of physical aggression trajectories from ages 6 to 15 years. METHODS: In this study, logistic regression analysis was used to identify parental and child characteristics that distinguished trajectory group membership. RESULTS: For boys displaying high hyperactivity and high opposition in kindergarten, the odds of membership in the 2 high aggression groups were increased by factors of 3.0 (95% confidence interval [CI], 2.0-4.3) and 2.7 (95% CI, 1.9-3.8), respectively, compared with boys without these risks. Counterpart odds ratios for the risk factors of mothers' teen-onset of parenthood and low educational attainment were 1.6 (95% CI, 1.1-2.2) and 1.8 (95% CI, 1.3-2.4), respectively. Only the maternal characteristics distinguished between the trajectory of persistently physical high aggression and the trajectory starting high but subsequently declining. For the 2 maternal risk factors combined, the odds ratio of persisting in high level physical aggression was 9.4 (95% CI, 2.9-30.4). CONCLUSIONS: Kindergarten boys displaying high levels of opposition and hyperactivity are at high risk of persistent physical aggression. However, among kindergarten boys who display high levels of physical aggression, only mothers' low educational level and teenage onset of childbearing distinguish those who persist in high levels of physical aggression.

Trajectories of boys' physical aggression, opposition, and hyperactivity on the path to physically violent and nonviolent juvenile delinquency.

A semi-parametric mixture model was used with a sample of 1,037 boys assessed repeatedly from 6 to 15 years of age to approximate a continuous distribution of developmental trajectories for three externalizing behaviors. Regression models were then used to determine which trajectories best predicted physically violent and nonviolent juvenile delinquency up to 17 years of age. Four developmental trajectories were identified for the physical aggression, opposition, and hyperactivity externalizing behavior dimensions: a chronic problem trajectory, a high level near-desister trajectory, a moderate level desister trajectory, and a no problem trajectory. Boys who followed a given trajectory for one type of externalizing problem behavior did not necessarily follow the same trajectory for the two other types of behavior problem. The different developmental trajectories of problem behavior also led to different types of juvenile delinquency. A chronic oppositional trajectory, with the physical aggression and hyperactivity trajectories being held constant, led to covert delinquency (theft) only, while a chronic physical aggression trajectory, with the oppositional and hyperactivity trajectories being held constant, led to overt delinquency (physical violence) and to the most serious delinquent acts.

Future needs: research, education, and service.

Sections on research, education, and service summarize efforts that are needed to control the workplace transmission of TB and measures that can be taken while research is being carried out. Topics include ways to identify infectious patients, techniques for measuring the airborne concentration of TB, and the need for surveillance programs.

Control of tuberculosis in the workplace: engineering controls.

In this review of engineering controls that can be used to check the spread of tuberculosis in health care settings, the authors address types of ventilation and supplements to ventilation such as HEPA filtration and ultraviolet germicidal irradiation. They also specifically cover engineering controls for use during medical procedures that pose an increased risk for transmission of TB.

Exposure of sheet-metal workers to asbestos during the construction and renovation of commercial buildings in New York City. A case study in social medicine.

New York City sheet-metal workers have a history of significant exposure to asbestos. Prior to 1972 when the use of sprayed asbestos insulation was banned in New York City, sheet-metal workers involved in building construction were exposed as they worked adjacent to spraying operations. Subsequent to that date, exposure continued as they renovated these same buildings. In 1982 the Occupational Health Program of Montefiore Medical Center and the Albert Einstein College of Medicine initiated a multidimensional asbestos evaluation and intervention program for the sheet-metal industry and union in New York. The long-term goal of the program was to eliminate asbestos exposure through the safe, systematic removal of asbestos in New York City buildings, most likely a legislated solution. In the short term, we attempted to assess and reduce asbestos exposure in the sheet-metal trade by a series of steps consisting of: mortality and morbidity studies; a medical audit of clinical screening services provided to sheet-metal workers; a comprehensive health education program; development of safe work practices; evaluation of personal protective equipment; and investigation into and support of legislative and regulatory solutions to the problem of asbestos contamination of commercial buildings. This intervention can be seen as a case study in the practice of social medicine.

Asbestos disease screening by non-specialists: results of an evaluation.

We performed a medical audit of an asbestos disease screening program offered to New York City sheet metal workers by a corporate medical service. The screening program purported to evaluate the health status of workers exposed to asbestos in the past and present during construction and renovation of commercial buildings. Using current Occupational Safety and Health Administration (OSHA) regulations as a benchmark, medical records for more than 800 workers who took the examination between 1982-83 were reviewed; x-ray interpretations of the staff radiologist were compared with the interpretations of specialists in occupational lung diseases. The audit found inadequate record-keeping procedures, a lack of a comprehensive occupational history, poor notification and absence of any form of health education. Further, there was an extreme lack of concordance between the staff radiologist and the specialist readers in the interpretation of x-rays (kappa = .14 for pleural disease and .26 for asbestosis). To an increasing extent, occupational clinical services are being provided by corporate medical groups; such groups may not be familiar with occupational health problems.

Characteristics of individuals who identify a regular source of medical care.

Having a source where medical services are regularly received is an antecedent to securing high quality medical care; it facilitates access and indicates that the individual is not alienated from the health care delivery system. In this paper we develop models to characterize individuals, both children and adults, who claim a regular source of care. The models are estimated using a logit analysis (since the dependent variable is 0-1) applied to survey data on residents of East Palo Alto, California. These data indicate that in this low-income, predominately black population the most important factor influencing whether a child will have a regular source of medical care is whether the parents have a regular source. For adults, the anticipated need for care (as measured by health status), time in community, and sex were all found to be important. The type of individual least likely to have a regular source of care is a low-income, unmarried male who is in good health and is a recent arrival to the community. The individuals most likely to need easy access to medical care and continuity of care are most likely to have a regular source of care, and vice versa.