Defining nicotine dependence for genetic research: evidence from Australian twins

Background. Whether current criteria used to define nicotine dependence are informative for genetic research is an important empirical question. The authors used items of the DSM-IV and of the Heaviness of Smoking Index to characterize the nicotine dependence phenotype and to identify salient symptoms in a genetically informative community sample of Australian young adult female and mate twins. Method. Phenotypic and genetic factor analyses were performed on nine dependence symptoms (the seven DSM-IV substance dependence criteria and the two Heaviness of Smoking Index (HSI) items derived from the Fagerstrom Tolerance Questionnaire, time to first cigarette in the morning and number of cigarettes smoked per day). Phenotypic and genetic analyses were restricted to ever smokers. Results. Phenotypic nicotine dependence symptom covariation was best captured by two factors with a similar pattern of factor loadings for women and men. In genetic factor analysis item covariation was best captured by two genetic but one shared environmental factor for both women and men; however, item factor loadings differed by gender. All nicotine dependence symptoms were substantially heritable, except for the DSM-IV criterion of 'giving up or reducing important activities in order to smoke', which was weakly familial. Conclusions. The salient behavioral indices of nicotine dependence are similar for women and men. DSM-IV criteria of tolerance, withdrawal, and experiencing difficulty quitting and HSI items time to first cigarette in the morning and number of cigarettes smoked per day may represent the most highly heritable symptoms of nicotine dependence for both women and men.

A transdisciplinary approach to adolescent forensic mental health

Objective: To examine new strategies which may be implemented to address the significant mental health and substance abuse problems of young people within the juvenile justice system. Method: Wide-ranging literature review of mental health problems within the juvenile justice population is given, illustrating the high prevalence of mental health problems within this cohort of young people. Reference is made to the differing demographics and agendas of the American justice system compared to that found in Australia. Results: It is suggested that new initiatives stemming from quality Australian studies are required in order to facilitate reform within adolescent forensic mental health. Psychiatrists need to be at the forefront of innovative policy delivery within the juvenile justice system. Conclusions: A transdisciplinary approach is required to meet the changing needs of young people within the juvenile justice system. Such a system of care recognizes that these young people and their families have multiple needs that cross traditional boundaries and a collaborative approach across agencies is essential at both the policy and practical level. Psychiatrists have an important role to play in the development of these services. A systemic process to address such needs is offered.

Identifying and predicting adolescent smokers' developmental trajectories

Very few studies have defined trajectories of smoking. In the present study, we modeled growth in adolescent smoking and empirically identified prototypical trajectories. We conceptualized escalation of smoking as a growth process and modeled rates of change and heterogeneity of these patterns using latent growth mixture modeling. The analysis identified six trajectories with low ambiguity about group membership (early rapid escalators, late rapid escalators, late moderate escalators, late slow escalators-smokers, stable puffers, and late slow escalators-puffers). A trajectory of quitters was not identified. We also examined predictors of the smoking trajectories. The predictors were assessed across the adolescent years and included variables related to smoking and other substance use, as well as a range of variables related to sociodemographic factors and mental health. Observed change in the pattern of predictors across age has implications for the mechanism of effect of these variables in relation to smoking trajectories, including predictors that differentiated among daily smokers, variables that may determine the trajectory (e.g., friends smoking), and variables that may result from the trajectory (e.g., marijuana use, less attachment to friends).

Same-sex attracted youths: Suicide and related factors

Same-sex attracted youths comprise 10 percent to 11 percent of the secondary school population although not all of those who experience same-sex attraction will adopt a gay, lesbian, transgender or transsexual lifestyle. Most, if not all, will experience homophobia in one or more of its forms. Many of these young people will cope well with the heterocentric attitudes and prejudices prevalent in secondary schools and the wider community and make the transition into adulthood having learned how to mask their sexual preferences or develop effective coping mechanisms to deal with homophobia. Some will succumb to the pressures they experience and seek less ideal solutions that include drug use and promiscuity. Some will take their own lives. This article draws attention to the complications of same-sex attraction and argues for a school and community response that recognises and appreciates the positive contributions that diversity of sexual preference brings to any community.

Escalation and deceleration of offending behaviours from adolescence to early adulthood

Relatively little longitudinal research is available in Australia to describe I the age/crime relationship in much detail, particularly patterns of offending occurring during the transition from adolescence to early adulthood. This paper addresses this issue using self-reported criminal involvement from a school-based sample, a group of socially disadvantaged individuals, and a group of officially identified offenders. The findings support the widespread research that rates of offending peak during adolescence, at which time offending is widespread, and that the criminal career is of relatively short duration. However, the results also demonstrate that the age/crime curve is not a unitary phenomenon. The type of offending behaviour being considered, the gender of the population, and the perpetrator's exposure to the criminal justice system contribute to the variability in the curve. In this study, the prevalence and mean level of overall offending for the total sample was higher during early adulthood than adolescence for vehicle offences and drug-use, rates of theft were similar in both periods, and vandalism and serious offending were lower. In addition, socially disadvantaged young people reported involvement in crime that peaked and desisted earlier in the life course compared to the school-based sample, and gender differences within these groups were also found. For the school-based sample, offending for females began and desisted earlier than for males, but within the at-risk group, the opposite was true. Implications for crime-prevention programming are discussed.