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OBJECTIVE: To assess if the lithium dosage prescribed according to the Pepin method leads to therapeutic serum concentrations of lithium. METHODS: For 13 healthy volunteers, the initial daily doses of lithium were calculated according to the Pepin formula with a view to obtaining a serum lithium level of 0.8 mmol/L. Lithium was administered twice daily for 21 days, and blood samples were drawn daily, 12 hours after the last dose was taken. Dosage was adjusted if serum concentrations were below 0.6 mmol/L or above 1.0 mmol/L or if major side effects were reported. RESULTS: Daily lithium doses ranged from 1050 mg to 1950 mg (mean 1569 mg, standard deviation [SD] 291 mg), The mean serum lithium concentrations for weeks 1, 2 and 3 were 0.74 mmol/L (SD 0.19 mmol/L), 0.67 mmol/L (SD 0.22 mmol/L) and 0.69 mmol/L (SD 0.13 mmol/L), respectively. Within-subject variance was negligible. Sixty-eight percent of the serum lithium concentration measurements fell between 0.57 mmol/L and 0.83 mmol/L, and 84% fell within the recommended therapeutic range of 0.60 mmol/L and 1.20 mmol/L. CONCLUSIONS: The Pepin method is a safe but conservative method for predicting the appropriate daily dose of lithium.

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Epidemiological surveys of child and adolescent mental disorders often rely on multiple informants to get a complete diagnostic picture. A consistent finding in the literature is that different informants often do not identify the same children as being disordered. However, because current strategies for estimating interinformant agreement often involve categorizing children using less than perfectly sensitive and/or specific symptoms, biased estimates of interinformant agreement are likely. The aim of this report was to illustrate how latent class analysis (LCA) can be used to model interinformant agreement in the absence of a "gold standard". The proposed model consists of informant-specific latent variables each made up of two or more latent classes corresponding to different levels of symptomatology. Unlike most previous applications of LCA this model allows us to model the extent to which the prevalence of the disorder is the same across informants; and, in addition, the association between informants. The data set comes from a prospective longitudinal study of 2,264 children from Quebec (1,155 boys and 1,109 girls). In grade 2, teachers and mothers independently rated each child on three physical aggression behavior symptoms. We satisfactorily accounted for the cross-classification of the behavior symptoms by postulating the existence of two latent variables--one for each informant each made up of three latent classes of children: low-, medium-, and high-aggressive. The results showed that the prevalence of low- and medium-aggressive children in the population differed from teacher to mother, but that the prevalence of high-aggressive children did not. We found that the association between teacher and mother was large and positive and did not vary according to the child's physical aggression state or gender; in contrast, the association between physical aggression and gender was not the same for mother and teacher. Limitations and other potential applications of the proposed model are discussed.

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This study examined the controversial practice of grade retention and children's academic and behavioral adjustment using data from the Quebec Longitudinal Study of Kindergarten Children. We employed an autoregressive modeling technique to detect the impact of being held back during primary school on subsequent academic performance and behavioral development until age 12 years. The results indicate both a short- and long-term negative influence on academic performance for boys and girls. Children's anxious, inattentive, and disruptive behaviors persisted and, in some cases, worsened after grade retention. These prospective associations were long lasting and more pronounced when grade retention occurred early in primary school. Boys were more vulnerable to the negative influence of grade retention on academic performance and classroom disruptiveness. Disruptive behavior in girls was comparatively less associated with long-term consequences than boys. Nevertheless, girls experienced both short- and long-term academic performance problems in the aftermath of grade retention. Children's prosocial behavior appeared unaffected by grade retention. These results are independent of what would have been expected by the natural course of academic and behavioral development.

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OBJECTIVE: Minor physical anomalies are considered indicators of disruption in fetal development. They have been found to predict behavioral problems and psychiatric disorders. This study examined the extent to which minor physical anomalies, family adversity, and their interaction predict violent and nonviolent delinquency in adolescence. METHOD: Minor physical anomalies were assessed in a group of 170 adolescent boys from low socioeconomic status neighborhoods of Montréal. The boys had been enrolled in a longitudinal study since their kindergarten year, when an assessment of family adversity had been made on the basis of familial status and the parents' occupational prestige, age at the birth of the first child, and educational level. Adolescent delinquency was measured by using self-reported questionnaires and a search of official crime records. RESULTS: Results from logistic regression analyses indicated that both the total count of minor physical anomalies and the total count of minor physical anomalies of the mouth were significantly associated with an increased risk of violent delinquency in adolescence, beyond the effects of childhood physical aggression and family adversity. Similar findings were not found for nonviolent delinquency. CONCLUSIONS: Children with a higher count of minor physical anomalies, and especially a higher count of anomalies of the mouth, could be more difficult to socialize for different and additive reasons: they may have neurological deficits, and they may have feeding problems in the first months after birth. Longitudinal studies of infants with minor physical anomalies of the mouth are needed to understand the process by which they fail to learn to inhibit physical aggression.

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This study examined the role of ADHD in the association between physical aggression and two types of executive functions. Boys received a cognitive-neuropsychological test battery over the ages of 13, 14, and 15 years. Diagnostic Interview Schedule for Children (DISC 2.25) data were collected from the boys and one parent between ages 14 and 16, and an IQ estimate was obtained at age 15. Three groups, differing in stability and level of physical aggression since kindergarten, were formed: Stable Aggressive, Unstable Aggressive, and Non-aggressive. Composite scores of validated executive function tests of working memory representing subjective ordering and conditional association learning were formed. A MANCOVA (N = 149) using ADHD status, teacher-rated negative emotionality, general memory abilities, and IQ as covariates was performed on the two composite scores. ADHD and teacher-rated emotionality did not provide significant adjustment to the dependent variables. Number of ADHD symptoms was negatively associated only with general memory and IQ. General memory contributed significantly to adjusting for conditional association test scores. Group differences indicated lower conditional association scores for Unstable Aggressive boys relative to the other groups. Both IQ and general memory abilities interacted with subjective ordering within the groups. Specifically, Stable Aggressive boys performed poorly on this measure and did not benefit from increases in IQ whereas Nonaggressive boys performed best and were not disadvantaged by lower general memory abilities. This suggests a relationship exists between aspects of working memory and a history of physical aggression regardless of ADHD and IQ.

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Using data from the Montreal Longitudinal-Experimental Study, we examined the impact of poverty (and its correlate, family configuration status) on academic placement and self-reported delinquency in boys at age 16. We then investigated whether the relation between family economic hardship and antisocial behaviour is direct or indirect by considering the value of parenting practices and academic failure as process variables in the model. Data included official records, and parent, teacher, and self-reports. The temporal intensity of poverty was classified into five categories: never-poor; always-poor; poor-earlier; poor-later; and transitory-poverty. Family configuration status was classified by both temporal characteristics and number of marital transitions: intact-family; short-term-single; long-term-single; short-term-remarried; long-term-remarried; and multiple-marital-transitions. Results revealed that when maternal education and early childhood behaviour were controlled, poverty had an effect on both academic failure and extreme delinquency. This effect was independent of family configuration status. Although they both significantly predicted extreme delinquency on their own, academic failure and parental supervision did not mediate the relationship between poverty and delinquency. Divorce increased the risk of theft and fighting at age 16, regardless of financial hardship. Parental supervision only helped explain the effects of divorce on boys' fighting.

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The relationship of timing of early parental separation to psychosocial development of daughters was examined in 77 girls, 6-9 years of age over a four-year period. Disruptive behavior across contexts was prevalent in girls separated between birth and two years of age. Girls separated between three and five years of age showed more externalizing behavior problems, but only in school. Results suggest that early parental separation has more pervasive and stable negative effects on psychosocial adjustment of girls in this age group in single-parent families. Implications of the findings and directions for research are discussed.

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Reduced pain perception has been observed in many studies of spontaneously hypertensive rats and human hypertensive patients. To determine whether a reduced sensitivity to pain could be observed in a group of clearly normotensive individuals who may be at risk for hypertension, a mild to moderate pain stimulus was administered to 177 14-year-old boys. Boys with a normatively elevated resting systolic blood pressure tolerated mechanical finger pressure significantly longer than boys with lower blood pressure. As well, boys with both normatively elevated resting systolic blood pressure and a parental history of hypertension reported significantly less pain during finger pressure than lower risk participants. These findings could not be explained by personality factors and suggest that hypertension-related hypoalgesia is associated with processes involved in the development of the disorder.

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We employed an autoregressive modelling technique with data from the Québec Longitudinal Study to prospectively examine the developmental impact of family transition on behaviour while controlling for predivorce and preremarriage effects. Teachers rated children's anxious, hyperactive, physically aggressive, oppositional, and prosocial behaviour every 2 years from kindergarten through to the end of elementary school. Once individual and parental characteristics and antecedent family events were controlled, children who experienced parental divorce before age 6 exhibited comparatively more behavioural disturbance than their peers whose parents divorced later. With the exception of a protective effect on hyperactive behaviour, remarriage did not have a significant impact on children's behaviour when the legacy of divorce was controlled. Although the results suggest that children of divorced parents show difficulty in many areas of functioning, the effects of family transition on behavioural development were dependent on the child's age and the specific behavioural dimension assessed. Compared to other points in development, early childhood divorce was associated with long-term increases in anxious, hyperactive, and oppositional behaviour during later childhood. The effects of divorce on children's fighting were short-lived. Unlike previous prospective studies that suggest predivorce effects, we did not observe behavioural disturbance prior to divorce or remarriage.

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It is unclear whether stably aggressive boys would be characterized by high or low pain sensitivity. Adolescent boys in whom physical aggression, executive functioning, anxiety, and family adversity had been assessed longitudinally formed three groups who differed in stability of physical aggression: stable, unstable, and non-aggressive. Stable aggressives were the least pain sensitive, whereas unstable aggressives were the most pain sensitive. While at low levels of executive functioning pain sensitivity could not be distinguished between the aggressive groups, at high levels unstable aggressives reported even more pain, whereas stable aggressives reported even less pain. Variations in anxiety were associated strongly with pain sensitivity in unstable aggressives. High pain ratings were found in boys who had a moderate level of family adversity, and low pain ratings in boys with low or high adversity. The differences in pain sensitivity between the groups may be motivationally important to the frequency and type of aggression.

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Cognitive-neuropsychological tests were given to adolescent boys (N = 177) to investigate processes associated with physical aggression. Factor analysis yielded 4 factors representing verbal learning, incidental spatial learning, tactile-lateral ability, and executive functions. Physical aggression was assessed at ages 6, 10, 11, and 12, and 3 groups were created: stable aggressive, unstable aggressive, and nonaggressive. The authors found main effects for only the executive functions factor even when other factors were used as additional covariates in a step-down analysis; nonaggressive boys performed better than stable and unstable aggressive boys. The covariates family adversity and anxiety were both related only to the verbal learning factor. This study highlights the importance of deficits in executive function in the expression of physical aggression relative to other cognitive-neuropsychological functions.

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