Primrose Letcher

Cannabis and depression: An integrative data analysis of four Australasian cohorts☆

BACKGROUND This study presents an integrative data analysis of the association between frequency of cannabis use and severity of depressive symptoms using data from four Australasian cohort studies. The integrated data comprised observations on over 6900 individuals studied on up to seven occasions between adolescence and mature adulthood. METHODS Repeated measures data on frequency of cannabis use (not used/<monthly/≥monthly/≥weekly) and concurrently assessed depression scores were pooled over the four cohorts. Regression models were fitted to estimate the strength of association between cannabis use and depression. Fixed effects regression methods were used to control for confounding by non-observed fixed factors. RESULTS Increasing frequency of cannabis use was associated with increasing depressive symptoms (p<0.001). In the pooled data weekly users of cannabis had depression scores that were 0.32 (95%CI 0.27-0.37) SD higher than non-users. The association was reduced but remained significant (p<0.001) upon adjustment for confounding. After adjustment depression scores for weekly users were 0.24 (95%CI 0.18-0.30) SD higher than non-users. The adjusted associations were similar across cohorts. There was a weak age×cannabis use interaction (p<0.05) suggesting that the association was strongest in adolescence. Attempts to further test the direction of causality using SEM methods proved equivocal. CONCLUSIONS More frequent cannabis use was associated with modest increases in rates of depressive symptoms. This association was stronger in adolescence and declined thereafter. However, it was not possible from the available data to draw a definitive conclusion as to the likely direction of causality between cannabis use and depression.

Positive development in emerging adulthood

Positive functioning in the developmental period of emerging adulthood has received little investigation. The current study investigated components of positive development using confirmatory factor analysis of Australian Temperament Project data collected from 1,158 young adults aged 19–20 years. Positive development constructs that have been theoretically conceptualised were examined to test core concepts. Five first-order constructs were identified in this sample: Civic Action and Engagement, Social Competence, Life Satisfaction, Trust and Tolerance of Others, and Trust in Authorities and Organisations. A second-order positive development factor defined by these constructs provided good fit for the data. This model of positive development in emerging adulthood can provide an outcome measure that can then be used to investigate the developmental processes and pathways involved.

Precursors and correlates of anxiety trajectories from late childhood to late adolescence

The present research employed a prospective, multi-informant design to examine precursors and correlates of differing anxiety profiles from late childhood to late adolescence. The sample consisted of 626 boys and 667 girls who are participants in the Australian Temperament Project, a large, longitudinal, community-based study that has followed young peoples psychosocial adjustment from infancy to adulthood. The present research analyzes data collected from the first 12 waves of data, from 4–8 months to 17 years. Parents, primary school teachers, maternal and child health nurses, and from the age of 11 onward, the young people themselves have provided survey data. Trajectory analyses revealed three distinct patterns of self-reported anxiety from late childhood to late adolescence, comprising low, moderate, and high (increasing) trajectories, which differed somewhat between boys and girls. A range of parent- and teacher-reported factors was found to be associated with these trajectories, including temperament style, behavior problems, social skills, parenting, negative family events, and peer relationships. Compared with male trajectories, female trajectories were associated with a greater variety of psychosocial variables (including parenting and externalizing problems), which may partially account for the higher prevalence of anxiety in adolescent girls compared with boys. Findings shed light on gender-specific pathways to anxiety and the need for comprehensive, integrative approaches to intervention and prevention programs.

Associations between Early Childhood Temperament Clusters and Later Psychosocial Adjustment

The study adopted a person-centered approach to examine whether clusters of children could be identified on the basis of temperament profiles assessed on four occasions from infancy to early childhood, and if so whether differing temperament clusters were associated with subsequent differences in behavior problems, social skills, and school adjustment in middle and late childhood. Parent, teacher, and self-report data were obtained from a large community-based cohort sample of Australian children, followed prospectively from infancy to late childhood. Four temperament clusters were identified. Children in the clusters labeled as reactive/inhibited and poor attention regulation tended to have higher levels of later behavior problems than children in clusters labeled nonreactive/outgoing and high attention regulation. Results suggested that a person-oriented clustering approach can identify children on the basis of early temperament who are at greater risk for behavioral, academic, and social difficulties four to eight years later.

Parenting style as a moderator of the effect of temperament on adolescent externalising and internatlising behaviour problems

Abstract The direct and interactive effects of temperament and parenting were examined in the prediction of early adolescent externalising behaviour problems (conduct disorder and hyperactivity), internalising problems (depression and anxiety), and substance use, using data on 1,402 13- and 14-year-olds. Significant direct effects were found for four temperament factors (negative reactivity, task persistence, activity, and approach), and four parenting factors (warmth, power assertion, physical punishment, and monitoring). For those high in persistence, low in negative reactivity, or low in activity, problem outcomes were generally very rare, regardless of parenting. Prevalence of behaviour problems was generally elevated among those low in persistence, high in negotive reactivity, or high in activity, even in cases where parenting was high in positive qualities such as warmth and monitoring. Prevalence of certain behaviour problems was substantially elevated when low persistence, high negotive reactivity, or high activity occurred in combination with lower parental warmth or lower monitoring. The results suggest that parenting can play an important moderating role in the relationship of particular temperament characteristics to behavioural problems.

Differentiating three conceptualisations of the relationship between positive development and psychopathology during the transition to adulthood

The transition to adulthood is characterised by both great potential for positive change and a relatively high incidence of problem outcomes. A multidimensional model of positive development during the transition to adulthood (at 19-20 years) has recently been proposed. However, an unresolved question regarding the nature of positive development during this time is how best to conceptualise its relationship to psychopathology. We drew on data from 1158 participants in the Australian Temperament Project, a large longitudinal community-based study that has followed young peoples psychosocial adjustment from infancy to early adulthood. Using structural equation modelling, we compared three models reflecting different conceptualisations of the relationship between positive development and psychopathology. The results suggest that positive development and psychopathology are best modelled as separate but correlated constructs. Hence, development in one domain is likely to influence the other, although separate and specific developmental pathways are also likely to be operating.

The relationship between positive development and psychopathology during the transition to adulthood: A person-centred approach

The transition to adulthood is characterised by potential for both positive development and problem outcomes such as psychopathology, yet little is known about relationships between the two. Given the diversity of pathways observed during this transition period, there is likely to be significant heterogeneity in young peoples experiences of these outcomes. Drawing on data from 1158 19-20 year olds in the Australian Temperament Project and using latent profile analysis, we identified six subgroups. For most, higher positive development was associated with lower psychopathology and vice versa. One group (33.6%) was high across all positive development measures and low on psychopathology, and another (47.7%) average in both areas. The remaining four groups were low on positive development but differentiated by average psychopathology (4.7%), high internalising (5.5%), and moderate (7.2%) and severe (1.3%) externalising problems. Tailored intervention strategies that address both the promotion of competence and prevention of problem outcomes are needed.

The effect of low parental warmth and low monitoring on disordered eating in mid-adolescence: Findings from the Australian Temperament Project.

OBJECTIVE To investigate the interactions between low parental warmth and monitoring at age 13-14 years and disordered eating attitudes and behaviours at age 15-16 years. METHOD Data on 1300 (667 females) adolescents and their parents were drawn from The Australian Temperament Project (ATP), a 30 year (15 wave) population based longitudinal study of social-emotional development. Parent participants completed surveys on parenting practices in late childhood, and adolescent participants reported disordered eating using the drive for thinness and bulimia subscales of the Eating Disorder Inventory (EDI) and an additional body dissatisfaction scale. Interaction was examined on the additive scale by estimating super-additive risk; i.e., risk in excess of the sum of individual risks. RESULTS For boys, neither parental warmth or monitoring, nor their interaction, was related to disordered eating. For girls, low parental warmth (alone) was associated with bulimic behaviours. In contrast, exposure to both low monitoring and warmth was associated with ∼3½-fold, ∼4-fold and ∼5-fold increases in the odds of reporting body dissatisfaction, drive for thinness and bulimia, respectively. For body dissatisfaction and drive for thinness, risk associated with joint exposure exceeded the sum of individual risks, suggesting an additive interaction between parenting styles. CONCLUSION Further investment in family-level interventions that focus on promoting parental monitoring behaviour and a warm parent-child relationship remain important strategies for preventing a range of disordered eating behaviours in adolescents.

The natural history of internalizing behaviours from adolescence to emerging adulthood: findings from the Australian Temperament Project

BACKGROUND The aims of the study were to describe the patterning and persistence of anxiety and depressive symptoms from adolescence to young adulthood and to examine long-term developmental relationships with earlier patterns of internalizing behaviours in childhood. METHOD We used parallel processes latent growth curve modelling to build trajectories of internalizing from adolescence to adulthood, using seven waves of follow-ups (ages 11-27 years) from 1406 participants of the Australian Temperament Project. We then used latent factors to capture the stability of maternal reported child internalizing symptoms across three waves of early childhood follow-ups (ages 5, 7 and 9 years), and examined relationships among these patterns of symptoms across the three developmental periods, adjusting for gender and socio-economic status. RESULTS We observed strong continuity in depressive symptoms from adolescence to young adulthood. In contrast, adolescent anxiety was not persistent across the same period, nor was it related to later depressive symptoms. Anxiety was, however, related to non-specific stress in young adulthood, but only moderately so. Although childhood internalizing was related to adolescent and adult profiles, the associations were weak and indirect by adulthood, suggesting that other factors are important in the development of internalizing symptoms. CONCLUSIONS Once established, adolescent depressive symptoms are not only strongly persistent, but also have the potential to differentiate into anxiety in young adulthood. Relationships with childhood internalizing symptoms are weak, suggesting that early adolescence may be an important period for targeted intervention, but also that further research into the childhood origins of internalizing behaviours is needed.

Negative reactivity and parental warmth in early adolescence and depressive symptoms in emerging adulthood

Objective Cross‐sectional research suggests that relationships between temperamental negative reactivity and adolescent depressive symptoms may be moderated by parental warmth. The primary purpose of this study was to conduct the first prospective analysis of this relationship. Method Data from 1,147 families in an Australian population‐based longitudinal study were used to examine: (1) temporal relationships between negative reactivity in early adolescence (13–14 years) and depressive symptoms in emerging adulthood (19–20 years); (2) the moderating role of parent‐reported warmth in early adolescence (13–14 years); and (3) the moderating role of child gender. Hierarchical multiple regression was conducted to test the hypothesis that parental warmth would moderate the relationship between early adolescent negative reactivity and depressive symptoms in emerging adulthood. Results After accounting for previous depressive symptoms at age 13–14 years, negative reactivity was positively associated with later depressive symptoms. By contrast, parental warmth at 13–14 years was negatively associated with later depressive symptoms for females but not males. Parental warmth did not moderate the association between early adolescent negative reactivity and subsequent depressive symptoms. Conclusions This study was the first to use prospective data to assess the protective effects of early adolescent parental warmth on the association between negative reactive temperaments and early adult depressive symptoms. Findings suggest that parental warmth for negatively reactive children provides only concurrent protection against subsequent depressive risk. This study did not examine parent–child transactional models, which may, in future longitudinal research, improve understanding of how trajectories of parent–child goodness‐of‐fit contribute to depressive symptoms.