Adolescent alcohol-use trajectories in the transition from high school

A cohort of 3300 students from high schools across Victoria, Australia, were surveyed regarding their patterns of alcohol consumption from mid-1993 to 1995. The first wave of data was collected halfway through the students' final year of school (year 12). Students were then resurveyed 3 months following school completion and on two subsequent occasions, each separated by 6-month intervals. Analysis of the four waves of data indicated that five longitudinal patterns (trajectories) characterized temporal trends in male and female alcohol use through the transition from high school. Stable non-use trajectories were evident for 17% of males and 16% of females. Trajectories of less than weekly use characterized 45% of females and 46% of males, and showed little tendency to escalate toward harmful use. Among those using alcohol on a weekly or more frequent basis in high school, with few exceptions, use continued with at least the same frequency, but the quantity of alcohol consumed tended to escalate over time toward harmful levels. Overall, findings indicate that patterns of alcohol use tend to be stable over time, and more frequent alcohol use during the final year of high school tends to precede potentially harmful alcohol use following high school. Encouraging those high school students who consume alcohol once per week or more often to use alcohol on a less than weekly basis may be a valuable yet neglected harm minimization strategy.

Study protocol: the childhood to adolescence transition study (CATS)

Background
Puberty is a multifaceted developmental process that begins in late-childhood with a cascade of endocrine changes that ultimately lead to sexual maturation and reproductive capability. The transition through puberty is marked by an increased risk for the onset of a range of health problems, particularly those related to the control of behaviour and emotion. Early onset puberty is associated with a greater risk of cancers of the reproductive tract and cardiovascular disease. Previous studies have had methodological limitations and have tended to view puberty as a unitary process, with little distinction between adrenarche, gonadarche and linear growth. The Childhood to Adolescence Transition Study (CATS) aims to prospectively examine associations between the timing and stage of the different hormonally-mediated changes, as well as the onset and course of common health and behavioural problems that emerge in the transition from childhood to adolescence. The initial focus of CATS is on adrenarche, the first hormonal process in the pubertal cascade, which begins for most children at around 8 years of age.

Methods/Design
CATS is a longitudinal population-based cohort study. All Grade 3 students (8–9 years of age) from a stratified cluster sample of schools in Melbourne, Australia were invited to take part. In total, 1239 students and a parent/guardian were recruited to participate in the study. Measures are repeated annually and comprise student, parent and teacher questionnaires, and student anthropometric measurements. A saliva sample was collected from students at baseline and will be repeated at later waves, with the primary purpose of measuring hormonal indices of adrenarche and gonadarche.

Discussion
CATS is uniquely placed to capture biological and phenotypic indices of the pubertal process from its earliest manifestations, together with anthropometric measures and assessment of child health and development. The cohort will provide rich detail of the development, lifestyle, external circumstances and health of children during the transition from childhood through to adolescence. Baseline associations between the hormonal measures and measures of mental health and behaviour will initially be examined cross-sectionally, and then in later waves longitudinally. CATS will make a unique contribution to the understanding of adrenarche and puberty in children’s health and development.