Temporal patterns and psychosocial consequences of adolescent help-seeking behaviour

This doctoral thesis presented an investigation of adolescent help-seeking behaviour that is likely to inform future studies examining adolescent psychology. Few prior studies have examined the factor structures of typical social support measures to examine whether family help-seeking and family support are single constructs or can be conceptualised as separate constructs. This three-year longitudinal study investigated the temporal characteristics and psychosocial consequences of early adolescent help-seeking behaviour. Findings highlighted that family help-seeking can be measured separately from family support, and discussed the role of family help-seeking and support in reducing adverse outcomes (e.g. mental health problems, school disengagement) for adolescents. The discussion contends there is interplay between family help-seeking and family support; however, the two constructs represent separate components within an over-arching adaptive process, and should be conceptualised and measured in this manner.

Young adult sequelae of adolescent cannabis use: an integrative analysis

 Background: Debate continues about the consequences of adolescent cannabis use. Existing data are limited in statistical power to examine rarer outcomes and less common, heavier patterns of cannabis use than those already investigated; furthermore, evidence has a piecemeal approach to reporting of young adult sequelae. We aimed to provide a broad picture of the psychosocial sequelae of adolescent cannabis use. Methods: We integrated participant-level data from three large, long-running longitudinal studies from Australia and New Zealand: the Australian Temperament Project, the Christchurch Health and Development Study, and the Victorian Adolescent Health Cohort Study. We investigated the association between the maximum frequency of cannabis use before age 17 years (never, less than monthly, monthly or more, weekly or more, or daily) and seven developmental outcomes assessed up to age 30 years (high-school completion, attainment of university degree, cannabis dependence, use of other illicit drugs, suicide attempt, depression, and welfare dependence). The number of participants varied by outcome (N=2537 to N=3765). Findings: We recorded clear and consistent associations and dose-response relations between the frequency of adolescent cannabis use and all adverse young adult outcomes. After covariate adjustment, compared with individuals who had never used cannabis, those who were daily users before age 17 years had clear reductions in the odds of high-school completion (adjusted odds ratio 0·37, 95% CI 0·20-0·66) and degree attainment (0·38, 0·22-0·66), and substantially increased odds of later cannabis dependence (17·95, 9·44-34·12), use of other illicit drugs (7·80, 4·46-13·63), and suicide attempt (6·83, 2·04-22·90). Interpretation: Adverse sequelae of adolescent cannabis use are wide ranging and extend into young adulthood. Prevention or delay of cannabis use in adolescence is likely to have broad health and social benefits. Efforts to reform cannabis legislation should be carefully assessed to ensure they reduce adolescent cannabis use and prevent potentially adverse developmental effects. Funding: Australian Government National Health and Medical Research Council. © 2014 Elsevier Ltd.

Reassessing the Effects of Early Adolescent Alcohol Use on Later Antisocial Behavior : A Longitudinal Study of Students in Victoria, Australia and Washington State, United States

The effect of early adolescent alcohol use on antisocial behavior was examined at one- and two-year follow-up in Washington, United States and Victoria, Australia. Each state used the same methods to survey statewide representative samples of students (N = 1,858, 52% female) in 2002 (Grade 7 [G7]), 2003 (Grade 8 [G8]), and 2004 (Grade 9 [G9]). Rates of lifetime, current, frequent, and heavy episodic alcohol use were higher in Victoria than Washington State, whereas rates of five antisocial behaviors were generally comparable across states. After controlling for established risk factors, few associations between alcohol use and antisocial behavior remained, except that G7 current use predicted G8 police arrests and stealing and G9 carrying a weapon and stealing; G7 heavy episodic use predicted G8 and G9 police arrests; and G7 lifetime use predicted G9 carrying a weapon. Hence, risk factors other than alcohol were stronger predictors of antisocial behaviors.

The influence of parenting style on adolescent substance use.

 The aim of this thesis were to establish whether specific parenting behaviours were better predictors of adolescent alcohol and drug use. The results suggest that in early adolescence specific parenting behaviours were more direct predictors of the development of adolescent substance use than the more complex parenting style categories.

What is the role of tobacco control advertising intensity and duration in reducing adolescent smoking prevalence? Findings from 16 years of tobacco control mass media advertising in Australia

ABSTRACT
Objective: To examine how the intensity and duration of tobacco control advertising relate to adolescent smoking prevalence.
Methods: Australian students (aged 12–17 years) participating in a national survey conducted triennially between 1993 and 2008 (sample size range 12 314–16 611). The outcome measure was students’ smoking in the previous 4 weeks collected through anonymous, self-completed surveys. For each student, monthly targeted rating points (TRPs, a measure of television advertising exposure) for tobacco control advertising was calculated for the 3 and 12 months prior to surveying. For each time period, cumulative TRPs exposure and exposure to three intensity levels (≥100 TRPs/month; ≥400 TRPs/month; ≥800 TRPs/month) over increasing durations (eg, 1 month, 2 months, etc) were calculated. Logistic regression examined associations between TRPs and adolescent smoking after controlling for demographic and policy variables.
Results: Past 3-month cumulative TRPs were found to have an inverse relationship with smoking prevalence. Low TRPs exposure in the past 12 months was positively associated with adolescent smoking prevalence. However, smoking prevalence reduced with cumulative exposure levels above 5800 cumulative TRPs. Additionally, exposure to ≥400 TRPs/month and ≥800 TRPs/month were associated with reduced likelihood of smoking, although the duration needed for this effect differed for the two intensity levels. When intensity was ≥400 TRPs/month, the odds of smoking only reduced with continuous exposure. When intensity was ≥800 TRPs/month, exposure at levels less than monthly was associated with reductions in smoking prevalence.
Conclusions: Both antismoking advertising intensity and duration are important for ensuring reductions in adolescent smoking prevalence.

A longitudinal evaluation of the resilient families randomized trial to prevent early adolescent depressive symptoms

This study aimed to evaluate whether an intervention prevented the development of depressive symptoms through the early years of secondary school (Grades 7 to 9 - mean ages 12.3 to 14.5 years) in Victoria, Australia. Twelve schools were randomized to a universal preventative intervention (including a student social relationship/emotional health curriculum, and parent/caregiver parenting education); 12 were randomized as control schools. Multivariate regression analyses used student self-report to predict depressive symptoms at 26-month follow-up (13-months after intervention completion) from baseline measures and intervention status (N = 2027). There was no overall intervention effect on depressive symptoms. However, intervention students with moderate symptoms whose parents attended parent education events had a significantly reduced risk of depressive symptoms at follow-up. Future evaluations of interventions of this type should investigate: therapeutic processes; methods to increase recruitment into effective parent education events; and the potential to target assistance to students with high depressive symptoms.

Gender differences in adolescent depression: Differential female susceptibility to stressors affecting family functioning

Objective: The aim of this study was to examine associations between family-based stressors and depressive symptoms in adolescents.

Method: Participants were 10-14 year olds who participated in a large Australian population study (n=6,552). Depressive symptoms and pubertal development were assessed using the self-report Short Mood and Feelings Questionnaire and the Pubertal Development Scale. Three indicators of stress exposure were examined-low emotional closeness to parents, residential and school transitions, and family conflict. The effect of gender, stress exposure and the interaction of gender and stress exposure on depressive symptoms was tested using multivariate logistic regression.

Results: High family conflict, residential instability and low emotional closeness with parents were independently associated with adolescent depressive symptoms. There was a significant gender by emotional closeness interaction; females reporting low emotional closeness to their parents were 2.3 times more likely to report high depressive symptoms than females reporting high emotional connections with parents.

Conclusions: Female adolescents may be more susceptible to particular types of stresses and particularly the quality of the parent-child relationship.

A longitudinal study of the association of adolescent polydrug use, alcohol use and high school non-completion

AIMS: Failure to complete high school predicts substantial economic and social disadvantage in adult life. The aim of this study was to determine the longitudinal association of mid-adolescent polydrug use and high school non-completion, relative to other drug use profiles. DESIGN: A longitudinal analysis of the relationship between polydrug use in three cohorts at grade 9 (age 14-15 years) and school non-completion (reported post-high school). SETTING: A State-representative sample of students across Victoria, Australia. PARTICIPANTS: A total of 2287 secondary school students from 152 high schools. The retention rate was 85%. MEASUREMENTS: The primary outcome was non-completion of grade 12 (assessed at age 19-23 years). At grade 9, predictors included 30-day use of eight drugs, school commitment, academic failure and peer drug use. Other controls included socio-economic status, family relationship quality, depressive symptoms, gender, age and cohort. FINDINGS: Three distinct classes of drug use were identified-no drug use (31.7%), mainly alcohol use (61.8%) and polydrug use (6.5%). Polydrug users were characterized by high rates of alcohol, tobacco and cannabis use. In the full model, mainly alcohol users and polydrug users were less likely to complete school than non-drug users [odds ratio (OR) = 1.54, 95% confidence interval (CI) = 1.17-2.03) and OR = 2.51, 95% CI = 1.45-4.33), respectively, P < 0.001]. These effects were independent of school commitment, academic failure, peer drug use and other controls. CONCLUSIONS: Mid-adolescent polydrug use in Australia predicts subsequent school non-completion after accounting for a range of potential confounding factors. Adolescents who mainly consume alcohol are also at elevated risk of school non-completion.

Longitudinal prediction of mid-adolescent psychosocial outcomes from early adolescent family help seeking and family support

This study examined whether family help seeking and family support represented the same or distinct constructs and prospective associations between emergent constructs and psychosocial outcomes. Data were from 1,713 school-based adolescents participating in a randomized controlled trial, in Victoria, Australia. Family help seeking emerged as a single factor, distinct from family support, and was prospectively associated with improved psychosocial outcomes. Father closeness predicted lower depressive symptoms. Family help seeking predicted higher help seeking for peers. Interactions between family help seeking and family support on psychosocial outcomes were not apparent. Findings highlight the importance of examining family help seeking and family support separately in future studies of adolescents' help-seeking behavior.

Child and adolescent obesity: part of a bigger picture

The prevalence of childhood overweight and obesity has risen substantially worldwide in less than one generation. In the USA, the average weight of a child has risen by more than 5 kg within three decades, to a point where a third of the country's children are overweight or obese. Some low-income and middle-income countries have reported similar or more rapid rises in child obesity, despite continuing high levels of undernutrition. Nutrition policies to tackle child obesity need to promote healthy growth and household nutrition security and protect children from inducements to be inactive or to overconsume foods of poor nutritional quality. The promotion of energy-rich and nutrient-poor products will encourage rapid weight gain in early childhood and exacerbate risk factors for chronic disease in all children, especially those showing poor linear growth. Whereas much public health effort has been expended to restrict the adverse marketing of breastmilk substitutes, similar effort now needs to be expanded and strengthened to protect older children from increasingly sophisticated marketing of sedentary activities and energy-dense, nutrient-poor foods and beverages. To meet this challenge, the governance of food supply and food markets should be improved and commercial activities subordinated to protect and promote children's health.

An examination of the influence of maternal depression trajectories on child cognitive development and adolescent psychotic experiences

 This thesis investigated trajectories of maternal depression over time, and their influence on offspring's cognitive development in childhood and subsequent risk of psychotic experiences in early adolescence. Offspring’s IQ was also examined as a potential mediator of the relationship between maternal depression and offspring’s risk of psychotic experiences.

Adolescent substance use and educational attainment: an integrative data analysis comparing cannabis and alcohol from three Australasian cohorts

BACKGROUND: The relative contributions of cannabis and alcohol use to educational outcomes are unclear. We examined the extent to which adolescent cannabis or alcohol use predicts educational attainment in emerging adulthood. METHODS: Participant-level data were integrated from three longitudinal studies from Australia and New Zealand (Australian Temperament Project, Christchurch Health and Development Study, and Victorian Adolescent Health Cohort Study). The number of participants varied by analysis (N=2179-3678) and were assessed on multiple occasions between ages 13 and 25. We described the association between frequency of cannabis or alcohol use prior to age 17 and high school non-completion, university non-enrolment, and degree non-attainment by age 25. Two other measures of alcohol use in adolescence were also examined. RESULTS: After covariate adjustment using a propensity score approach, adolescent cannabis use (weekly+) was associated with 1½ to two-fold increases in the odds of high school non-completion (OR=1.60, 95% CI=1.09-2.35), university non-enrolment (OR=1.51, 95% CI=1.06-2.13), and degree non-attainment (OR=1.96, 95% CI=1.36-2.81). In contrast, adjusted associations for all measures of adolescent alcohol use were inconsistent and weaker. Attributable risk estimates indicated adolescent cannabis use accounted for a greater proportion of the overall rate of non-progression with formal education than adolescent alcohol use. CONCLUSIONS: Findings are important to the debate about the relative harms of cannabis and alcohol use. Adolescent cannabis use is a better marker of lower educational attainment than adolescent alcohol use and identifies an important target population for preventive intervention.

The relationship between personality traits and psychotic like experiences in a large non-clinical adolescent sample

Objective: The relationship between personality and psychosis is well established. It has been suggested that this relationship may be partly accounted for by higher levels of depression in individuals with certain personality traits. We explored whether the link between personality and psychotic symptoms is already apparent in adolescence, and if this association would still hold when depression was controlled for. Method: 654 secondary school students were surveyed via self-report questionnaires measuring the Five-Factor model of personality (NEO-FFI), depression (CES-D) and psychotic-like experiences (CAPE). Results: Positive associations were found between Neuroticism and all CAPE-subscales except Magical Thinking, which was in turn associated with all other personality traits when at high levels. Agreeableness was negatively associated with all CAPE-subscales, while Openness to Experience was only positively associated with Persecutory Ideas and Magical Thinking. After controlling for depression, many of the significant associations remained. Conclusion: Our findings suggest that the chance of having psychotic like experiences is more likely for adolescents with certain personality traits. These associations are not fully explained by depression, especially when psychotic experiences are at higher levels. Future research is needed to investigate if these personality traits might put a person at risk for the development of full-blown psychosis.

Peer group patterns of adolescent alcohol using behaviours in Victoria, Australia and Washington State, US

 The goal of this study was to examine and cross-nationally compare the peer group patterns of alcohol-drinking behaviors among cohorts of early adolescents (ages 11–14 years) in Victoria, Australia, and Washington State, United States. Latent transition analysis revealed that after 1 year, transitions congruent with peer influence (whereby non-drinking adolescents initiated alcohol use in the presence of drinking peers) and reverse peer influence were observed in both states; however, transitions congruent with peer selection (whereby drinking adolescents self-selected into drinking peer groups) were only observed among Victorian early adolescents. Findings were interpreted to suggest that Australian family and cultural norms that more commonly allow early adolescent alcohol use lead to a higher rate of peer selection.