How are you sleeping? Starting the conversation with fathers about their mental health in the early parenting years

BACKGROUND

Approximately 1 in 10 fathers of infants experience symptoms of common mental health disorders, prompting calls for paternal postpartum screening. However, numerous obstacles exist to screening implementation. The aim of this study was to provide preliminary evidence for an alternative approach that starts with asking fathers about their sleep.

METHODS

Using self-reported father data at 0 to 36 months postpartum (N=1204) from four Australian cohort studies, we assessed associations between responses to various single-item questions about sleep (good to poor), and scores on validated measures of mental health (depression, anxiety and stress). We conducted regressions, unadjusted and adjusted for father age, child age, household income, education, first or later child, and marital status, to test associations between sleep and each indicator of mental health. We then meta-analyzed effects and assessed interactions between sleep and each of the covariates.

RESULTS

Consistent associations between fathers' subjective poor sleep and depression, anxiety and stress were replicated across the four cohorts despite heterogeneity in the sleep questions. At the meta-analytic level, effects ranged from weak to moderate (0.25 to 0.37) and were robust to all adjustments. Interactions were only detected between family income and poor sleep, such that the association was stronger for high income fathers.

LIMITATIONS

This study does not address the sensitivity or specificity of single-item sleep questions for assessing paternal mental health risk.

CONCLUSIONS

A low-cost, non-stigmatizing single question to postpartum fathers about their sleep may present a gateway opportunity to enquiring about mental health.

Maternal bonding, negative affect, and infant social-emotional development: A prospective cohort study

BACKGROUND

Theoretical perspectives and empirical evidence suggest that maternal bonding and negative affect play a role in supporting infant social-emotional development (Branjerdporn et al., 2017; Kingston et al., 2012; O'Donnell et al., 2014; Van den Bergh et al., 2017). However, the complex pathways likely to exist between these constructs remain unclear, with limited research examining the temporal and potentially bi-directional associations between maternal bonding and negative affect across pregnancy and infancy.

METHODS

The interrelationships between maternal bonding, negative affect, and infant social-emotional development were examined using multi-wave perinatal data from an Australian cohort study (N = 1,579). Self-reported bonding and negative affect were assessed at each trimester, and 8 weeks and 12 months postpartum. The Bayley-III social-emotional scale was administered at age 12 months.

RESULTS

Results revealed strong continuities in bonding and negative affect across pregnancy and postpartum. Small associations (β = -.10 to -.20) existed between maternal negative affect during pregnancy and poor early bonding. Higher postnatal maternal bonding predicted infant social-emotional development (β = .17).

LIMITATIONS

Limitations include a somewhat advantaged and predominantly Anglo-Saxon sample of families, and the use of self-report measures (though with strong psychometric properties). These limitations should be considered when interpreting the study findings.

CONCLUSIONS

Maternal bonding and negative affect are interrelated yet unique constructs, with suggested developmental interplay between mother-to-infant bonding and infant social-affective development.

Hidden in Plain Sight? Men's Coping Patterns and Psychological Distress Before and During the COVID-19 Pandemic

Individuals cope with stress using multiple strategies, yet studies of coping profiles are rare. We draw data from a longitudinal study of Australian men (n = 272; 30-37 years), assessed before (T1) and during (T2) a nation-wide COVID-19 lockdown. We aimed to: (1) identify men's multi-strategy coping profiles before and during the pandemic; (2) assess cross-sectional (T1-T1, T2-T2) and prospective (T1-T2) associations between profiles and symptoms of psychological distress (stress, anxiety, depression, and anger); and (3) examine relationships between coping profiles and appraisals of pandemic-related stressors and options for coping. In latent profile analyses of 14 coping strategies, three profiles emerged that were largely consistent across T1 and T2: (1) Relaxed Copers (low use of all strategies), (2) Approach Copers, and (3) Dual Copers (high avoidant and moderate-high approach-oriented strategies). Compared to Relaxed and Approach Copers, men who were Dual Copers had elevated psychological distress cross-sectionally before (T1) and during (T2) the pandemic, but not prospectively. Post hoc analyses suggested this was because many men changed coping profiles in the context of the pandemic. Men with stable (T1-T2) or new (T2 only) Dual Coping profiles experienced greater psychological distress and more negative appraisals of pandemic stressors and options for coping. In sum, at the sample level, the composition of men's coping profiles and associations with mental health risk were relatively stable over time and contexts; however, many men appeared to respond to pandemic conditions by changing coping profile groups, with mostly positive mental health outcomes. Of concern were men who adopted more avoidant strategies (e.g., denial, self-distraction, disengagement, substance use, and self-blame) under pandemic conditions. These Dual Coper men also engaged in commonly observable approach-oriented behaviours (e.g., planning, active coping, humour, seeking practical social support) that may mask their vulnerability to mental health risk. Our findings highlight the clinical importance of enquiring about escalating or frequent avoidant coping even in the presence of more active and interactive approach-oriented behaviours.

Childhood disadvantage and adolescent socioemotional wellbeing as predictors of future parenting behaviour

INTRODUCTION

In extending work on early life antecedents of parenting, we investigate associations between childhood family history of disadvantage, adolescent socioemotional wellbeing, and age at first parenthood and subsequent parenting behaviour.

METHODS

Parent-child interactions were recorded when participants in the longitudinal Dunedin Multidisciplinary Health and Development Study (New Zealand) had a three-year-old child. Data were available for 358 mothers and 321 fathers, aged between 17.7 and 41.5 at the time of their child's birth. Associations between parenting and antecedent data on socioeconomic disadvantage, adolescent wellbeing and mental health, as well as current adult mental health and age at parenting, were tested for using structural equation modelling.

RESULTS

Family disadvantage in childhood and lower adolescent wellbeing was associated with less positive future parenting, but only adult (not adolescent) anxiety/depression symptoms were directly associated with parenting behaviour. Childhood family disadvantage was associated with further disadvantage across the life course that included less positive parenting of the next generation. In contrast, socioemotional wellbeing during adolescence and later age of onset of parenting were associated with more positive parenting.

CONCLUSIONS

Reducing childhood disadvantage and improving socioemotional wellbeing during childhood and adolescence is likely to have intergenerational benefits through better parenting of the next generation.

Profiles of Depressive Symptoms and Anger in Men: Associations With Postpartum Family Functioning

Background: Evidence suggests that men commonly experience depression as feelings of anger; yet, research has not investigated what this means for the manifestation of depressive symptoms in the early years of fatherhood and for key indicators of family functioning. Methods: Using data from a longitudinal cohort study of men at the normative age for entering fatherhood (28-32 years), we conducted latent class analyses to identify patterns of depressive symptoms and 3 sub-types of state anger (feeling; verbal; physical). We then assessed whether class membership was associated with paternity status (n = 535). In a subsample of fathers of infants aged up to 18 months (n = 162), we prospectively assessed associations with paternal-infant bonding, co-parenting, perceived social support, paternal involvement in childcare and alcohol use up to 2 years later. Results: Five classes emerged that differentiated men by anger and depressive symptom severity and by the degree to which men endorsed the feeling of wanting to express anger physically. Compared to the reference class with minimal symptoms, fathers had a higher probability of being in either the mild or most severe symptom classes. Men in symptomatic classes were at higher risk of lower levels of social support, co-parenting problems, and paternal-infant bonds. Class membership was not associated with alcohol use or paternal involvement in childcare. Conclusions: Our results reveal patterns of co-existing symptoms of depression and anger in fathers of infants that will be relevant to men's own need for support, their family safety, partner mental health and child developmental outcomes.

A comparison of penalised regression methods for informing the selection of predictive markers

Background

Penalised regression methods are a useful atheoretical approach for both developing predictive models and selecting key indicators within an often substantially larger pool of available indicators. In comparison to traditional methods, penalised regression models improve prediction in new data by shrinking the size of coefficients and retaining those with coefficients greater than zero. However, the performance and selection of indicators depends on the specific algorithm implemented. The purpose of this study was to examine the predictive performance and feature (i.e., indicator) selection capability of common penalised logistic regression methods (LASSO, adaptive LASSO, and elastic-net), compared with traditional logistic regression and forward selection methods.

Design

Data were drawn from the Australian Temperament Project, a multigenerational longitudinal study established in 1983. The analytic sample consisted of 1,292 (707 women) participants. A total of 102 adolescent psychosocial and contextual indicators were available to predict young adult daily smoking.

Findings

Penalised logistic regression methods showed small improvements in predictive performance over logistic regression and forward selection. However, no single penalised logistic regression model outperformed the others. Elastic-net models selected more indicators than either LASSO or adaptive LASSO. Additionally, more regularised models included fewer indicators, yet had comparable predictive performance. Forward selection methods dismissed many indicators identified as important in the penalised logistic regression models.

Conclusions

Although overall predictive accuracy was only marginally better with penalised logistic regression methods, benefits were most clear in their capacity to select a manageable subset of indicators. Preference to competing penalised logistic regression methods may therefore be guided by feature selection capability, and thus interpretative considerations, rather than predictive performance alone.

Association Between Maternal Perinatal Depression and Anxiety and Child and Adolescent Development: A Meta-analysis

IMPORTANCE

There is widespread interest in associations between maternal perinatal depression and anxiety and offspring development; however, to date, there has been no systematic, meta-analytic review on the long-term developmental outcomes spanning infancy through adolescence.

OBJECTIVE

To provide a comprehensive systematic review and meta-analysis of the extant literature on associations between maternal perinatal depression and anxiety and social-emotional, cognitive, language, motor, and adaptability outcomes in offspring during the first 18 years of life.

DATA SOURCES

Six databases were searched (CINAHL Complete, Cochrane Library, Embase, Informit, MEDLINE Complete, and PsycInfo) for all extant studies reporting associations between perinatal maternal mental health problems and offspring development to March 1, 2020.

STUDY SELECTION

Studies were included if they were published in English; had a human sample, quantitative data, a longitudinal design, and measures of perinatal depression and/or anxiety and social-emotional, cognitive, language, motor, and/or adaptability development in offspring; and investigated an association between perinatal depression or anxiety and childhood development.

DATA EXTRACTION AND SYNTHESIS

Of 27 212 articles identified, 191 were eligible for meta-analysis. Data were extracted by multiple independent observers and pooled using a fixed- or a random-effects model. A series of meta-regressions were also conducted. Data were analyzed from January 1, 2019, to March 15, 2020.

MAIN OUTCOMES AND MEASURES

Primary outcomes included social-emotional, cognitive, language, motor, and adaptability development in offspring during the first 18 years of life.

RESULTS

After screening, 191 unique studies were eligible for meta-analysis, with a combined sample of 195 751 unique mother-child dyads. Maternal perinatal depression and anxiety were associated with poorer offspring social-emotional (antenatal period, r = 0.21 [95% CI, 0.16-0.27]; postnatal period, r = 0.24 [95% CI, 0.19-0.28]), cognitive (antenatal period, r = -0.12 [95% CI, -0.19 to -0.05]; postnatal period, r = -0.25 [95% CI, -0.39 to -0.09]), language (antenatal period, r = -0.11 [95% CI, -0.20 to 0.02]; postnatal period, r = -0.22 [95% CI, -0.40 to 0.03]), motor (antenatal period, r = -0.07 [95% CI, -0.18 to 0.03]; postnatal period, r = -0.07 [95% CI, -0.16 to 0.03]), and adaptive behavior (antenatal period, r = -0.26 [95% CI, -0.39 to -0.12]) development. Findings extended beyond infancy, into childhood and adolescence. Meta-regressions confirmed the robustness of the results.

CONCLUSIONS AND RELEVANCE

Evidence suggests that perinatal depression and anxiety in mothers are adversely associated with offspring development and therefore are important targets for prevention and early intervention to support mothers transitioning into parenthood and the health and well-being of next-generation offspring.

Parental mental health before and during pregnancy and offspring birth outcomes: A 20-year preconception cohort of maternal and paternal exposure

BACKGROUND

Preterm birth (PTB) and small for gestational age (SGA) are increasingly prevalent, with major consequences for health and development into later life. There is emerging evidence that some risk processes begin before pregnancy. We report on associations between maternal and paternal common mental disorders (CMD) before and during pregnancy and offspring PTB and SGA.

METHODS

398 women with 609 infants and 267 men with 421 infants were assessed repeatedly for CMD symptoms before pregnancy between age 14 and 29 and during pregnancy. Associations between preconception and antenatal CMD symptoms and offspring gestational age/PTB and size for gestational age/SGA were estimated using linear and Poisson regression.

FINDINGS

In men, persistent preconception CMD across adolescence and young adulthood predicted offspring PTB after adjustment for ethnicity, education, BMI and adolescent substance use (adjusted RR 7·0, 95% CI 1·8,26·8), corresponding to a population attributable fraction of 31% of preterm births. In women, antenatal CMD symptoms predicted offspring PTB (adjusted RR 4·4, 95% CI 1·4,14·1). There was little evidence of associations with SGA.

INTERPRETATION

This first report of an association between paternal preconception mental health and offspring gestational age, while requiring replication in larger samples, complements earlier work on stress in animals, and further strengthens the case for expanding preconception mental health care to both men and women.

FUNDING

National Health and Medical Research Council (Australia), Victorian Health Promotion Foundation, Australian Rotary Health, Colonial Foundation, Perpetual Trustees, Financial Markets Foundation for Children (Australia), Royal Children's Hospital Foundation, Murdoch Children's Research Institute, Australian Research Council.

Early childhood attachment stability and change: a meta-analysis

Examining degrees of stability in attachment throughout early childhood is important for understanding developmental pathways and for informing intervention. Updating and building upon all prior meta-analyses, this study aimed to determine levels of stability in all forms of attachment classifications across early childhood. Attachment stability was assessed between three developmental epochs within early childhood: infancy, toddlerhood, and preschool/early school. To ensure data homogeneity, only studies that assessed attachment with methods based on the strange situation procedure were included. Results indicate moderate levels of stability at both the four-way (secure, avoidant, resistant, and disorganised; κ = 0.23) and secure/insecure (r = 0.28) levels of assessment. Meta-regression analysis indicated security to be the most stable attachment organisation. This study also found evidence for publication bias, highlighting a preference for the publication of significant findings.

Efficacy of a Smartphone App Intervention for Reducing Caregiver Stress: Randomized Controlled Trial

BACKGROUND

Caregivers play a pivotal role in maintaining an economically viable health care system, yet they are characterized by low levels of psychological well-being and consistently report unmet needs for psychological support. Mobile app-based (mobile health [mHealth]) interventions present a novel approach to both reducing stress and improving well-being.

OBJECTIVE

This study aims to evaluate the effectiveness of a self-guided mobile app-based psychological intervention for people providing care to family or friends with a physical or mental disability.

METHODS

In a randomized, single-blind, controlled trial, 183 caregivers recruited through the web were randomly allocated to either an intervention (n=73) or active control (n=110) condition. The intervention app contained treatment modules combining daily self-monitoring with third-wave (mindfulness-based) cognitive-behavioral therapies, whereas the active control app contained only self-monitoring features. Both programs were completed over a 5-week period. It was hypothesized that intervention app exposure would be associated with decreases in depression, anxiety, and stress, and increases in well-being, self-esteem, optimism, primary and secondary control, and social support. Outcomes were assessed at baseline, postintervention, and 3-4 months postintervention. App quality was also assessed.

RESULTS

In total, 25% (18/73) of the intervention participants were lost to follow-up at 3 months, and 30.9% (34/110) of the participants from the wait-list control group dropped out before the postintervention survey. The intervention group experienced reductions in stress (b=-2.07; P=.04) and depressive symptoms (b=-1.36; P=.05) from baseline to postintervention. These changes were further enhanced from postintervention to follow-up, with the intervention group continuing to report lower levels of depression (b=-1.82; P=.03) and higher levels of emotional well-being (b=6.13; P<.001), optimism (b=0.78; P=.007), self-esteem (b=-0.84; P=.005), support from family (b=2.15; P=.001), support from significant others (b=2.66; P<.001), and subjective well-being (b=4.82; P<.001). On average, participants completed 2.5 (SD 1.05) out of 5 treatment modules. The overall quality of the app was also rated highly, with a mean score of 3.94 out of a maximum score of 5 (SD 0.58).

CONCLUSIONS

This study demonstrates that mHealth psychological interventions are an effective treatment option for caregivers experiencing high levels of stress. Recommendations for improving mHealth interventions for caregivers include offering flexibility and customization in the treatment design.

TRIAL REGISTRATION

Australian New Zealand Clinical Trial Registry ACTRN12616000996460; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=371170.

A methodological review of fetal neurosonographic studies: New directions in assessment of neurodevelopmental risk for mental health problems

Most mental disorders are now considered to have neurodevelopmental origins, with a growing body of research pointing to neural alterations that predate birth. However, lack of established methods for reliable investigation of fetal brain development has limited research into early neural vulnerability. Using a systematic approach and quantitative evaluation of study methodology, we review neurosonographic studies of fetal brain structure with objective quality measures. A total of 81 studies were identified. High quality studies were identified for measurement of the corpus callosum, cerebellum, vermis, ventricles and frontal cortex, with reference ranges provided to facilitate future clinical research. Fewer and lower quality studies were available for subcortical structures, prompting a need for further research to create reliable reference ranges. Development and adoption of reference ranges for fetal brain structures should facilitate future research in neurosonographic evaluation of fetal brain development and lead to a better understanding of neurodevelopmental risk and resilience processes for mental disorders.

Maternal mental health and infant emotional reactivity: a 20-year two-cohort study of preconception and perinatal exposures

BACKGROUND

Maternal mental health during pregnancy and postpartum predicts later emotional and behavioural problems in children. Even though most perinatal mental health problems begin before pregnancy, the consequences of preconception maternal mental health for children's early emotional development have not been prospectively studied.

METHODS

We used data from two prospective Australian intergenerational cohorts, with 756 women assessed repeatedly for mental health problems before pregnancy between age 13 and 29 years, and during pregnancy and at 1 year postpartum for 1231 subsequent pregnancies. Offspring infant emotional reactivity, an early indicator of differential sensitivity denoting increased risk of emotional problems under adversity, was assessed at 1 year postpartum.

RESULTS

Thirty-seven percent of infants born to mothers with persistent preconception mental health problems were categorised as high in emotional reactivity, compared to 23% born to mothers without preconception history (adjusted OR 2.1, 95% CI 1.4-3.1). Ante- and postnatal maternal depressive symptoms were similarly associated with infant emotional reactivity, but these perinatal associations reduced somewhat after adjustment for prior exposure. Causal mediation analysis further showed that 88% of the preconception risk was a direct effect, not mediated by perinatal exposure.

CONCLUSIONS

Maternal preconception mental health problems predict infant emotional reactivity, independently of maternal perinatal mental health; while associations between perinatal depressive symptoms and infant reactivity are partially explained by prior exposure. Findings suggest that processes shaping early vulnerability for later mental disorders arise well before conception. There is an emerging case for expanding developmental theories and trialling preventive interventions in the years before pregnancy.

Study Protocol for the COVID-19 Pandemic Adjustment Survey (CPAS): A Longitudinal Study of Australian Parents of a Child 0-18 Years

BACKGROUND

The COVID-19 pandemic presents significant risks to the mental health and wellbeing of Australian families. Employment and economic uncertainty, chronic stress, anxiety, and social isolation are likely to have negative impacts on parent mental health, couple and family relationships, as well as child health and development.

OBJECTIVE

This study aims to: (1) provide timely information on the mental health impacts of the emerging COVID-19 crisis in a close to representative sample of Australian parents and children (0-18 years), (2) identify adults and families most at risk of poor mental health outcomes, and (3) identify factors to target through clinical and public health intervention to reduce risk. Specifically, this study will investigate the extent to which the COVID-19 pandemic is associated with increased risk for parents' mental health, lower well-being, loneliness, and alcohol use; parent-parent and parent-child relationships (both verbal and physical); and child and adolescent mental health problems.

METHODS

The study aims to recruit a close to representative sample of at least 2,000 adults aged 18 years and over living in Australia who are parents of a child 0-4 years (early childhood, N = 400), 5-12 years (primary school N = 800), and 13-18 years (secondary school, N = 800). The design will be a longitudinal cohort study using an online recruitment methodology. Participants will be invited to complete an online baseline self-report survey (20 min) followed by a series of shorter online surveys (10 min) scheduled every 2 weeks for the duration of the COVID-19 pandemic (i.e., estimated to be 14 surveys over 6 months).

RESULTS

The study will employ post stratification weights to address differences between the final sample and the national population in geographic communities across Australia. Associations will be analyzed using multilevel modeling with time-variant and time-invariant predictors of change in trajectory over the testing period.

CONCLUSIONS

This study will provide timely information on the mental health impacts of the COVID-19 crisis on parents and children in Australia; identify communities, parents, families, and children most at risk of poor outcomes; and identify potential factors to address in clinical and public health interventions to reduce risk.

The Victorian Intergenerational Health Cohort Study (VIHCS): Study design of a preconception cohort from parent adolescence to offspring childhood

BACKGROUND

There is increasing evidence that parental determinants of offspring early life development begin well before pregnancy.

OBJECTIVES

We established the Victorian Intergenerational Health Cohort Study (VIHCS) to examine the contributions of parental mental health, substance use, and socio-economic characteristics before pregnancy to child emotional, physical, social, and cognitive development.

POPULATION

Men and women were recruited from the Victorian Adolescent Health Cohort (VAHCS), an existing cohort study beginning in 1992 that assessed a representative sample of 1943 secondary school students in Victoria, Australia, repeatedly from adolescence (wave 1, mean age 14 years) to adulthood (wave 10, mean age 35 years).

METHODS

Victorian Adolescent Health Cohort participants with children born between 2006 and 2013 were recruited to VIHCS and invited to participate during trimester three, at 2 months postpartum, and 1 year postpartum. Parental mental health, substance use and socio-economic characteristics were assessed repeatedly throughout; infant characteristics were assessed postnatally and in infancy. Data will be supplemented by linkage to routine datasets. A further follow-up is underway as children reach 8 years of age.

PRELIMINARY RESULTS

Of the 1307 infants born to VAHCS participants between 2006 and 2013, 1030 were recruited to VIHCS. At VIHCS study entry, 18% of recruited parents had preconception common mental disorder in adolescence and young adulthood, 18% smoked daily in adolescence and young adulthood, and 6% had not completed high school. Half of VIHCS infants were female (48%), 4% were from multiple births, and 7% were preterm (<37 weeks' gestation).

CONCLUSIONS

Victorian Intergenerational Health Cohort Study is a prospective cohort of 1030 children with up to nine waves of preconception parental data and three waves of perinatal parental and infant data. These will allow examination of continuities of parental health and health risks from the decades before pregnancy to offspring childhood, and the contributions of exposures before pregnancy to offspring outcomes in childhood.

Pre-conception self-harm, maternal mental health and mother-infant bonding problems: a 20-year prospective cohort study

BACKGROUND

Self-harm in young people is associated with later problems in social and emotional development. However, it is unknown whether self-harm in young women continues to be a marker of vulnerability on becoming a parent. This study prospectively describes the associations between pre-conception self-harm, maternal depressive symptoms and mother-infant bonding problems.

METHODS

The Victorian Intergenerational Health Cohort Study (VIHCS) is a follow-up to the Victorian Adolescent Health Cohort Study (VAHCS) in Australia. Socio-demographic and health variables were assessed at 10 time-points (waves) from ages 14 to 35, including self-reported self-harm at waves 3-9. VIHCS enrolment began in 2006 (when participants were aged 28-29 years), by contacting VAHCS women every 6 months to identify pregnancies over a 7-year period. Perinatal depressive symptoms were assessed with the Edinburgh Postnatal Depression Scale during the third trimester, and 2 and 12 months postpartum. Mother-infant bonding problems were assessed with the Postpartum Bonding Questionnaire at 2 and 12 months postpartum.

RESULTS

Five hundred sixty-four pregnancies from 384 women were included. One in 10 women (9.7%) reported pre-conception self-harm. Women who reported self-harming in young adulthood (ages 20-29) reported higher levels of perinatal depressive symptoms and mother-infant bonding problems at all perinatal time points [perinatal depressive symptoms adjusted β = 5.40, 95% confidence interval (CI) 3.42-7.39; mother-infant bonding problems adjusted β = 7.51, 95% CI 3.09-11.92]. There was no evidence that self-harm in adolescence (ages 15-17) was associated with either perinatal outcome.

CONCLUSIONS

Self-harm during young adulthood may be an indicator of future vulnerability to perinatal mental health and mother-infant bonding problems.

A comparison of longitudinal modelling approaches: Alcohol and cannabis use from adolescence to young adulthood

BACKGROUND

Modelling trajectories of substance use over time is complex and requires judicious choices from a number of modelling approaches. In this study we examine the relative strengths and weakness of latent curve models (LCM), growth mixture modelling (GMM), and latent class growth analysis (LCGA).

DESIGN

Data were drawn from the Australian Temperament Project, a 36-year-old community-based longitudinal study that has followed a sample of young Australians from infancy to adulthood across 16 waves of follow-up since 1983. Models were fitted on past month alcohol use (n = 1468) and cannabis use (n = 549) across six waves of data collected from age 13-14 to 27-28 years.

FINDINGS

Of the three model types, GMMs were the best fit. However, these models were limited given the variance of numerous growth parameters had to be constrained to zero. Additionally, both the GMM and LCGA solutions had low entropy. The negative binomial LCMs provided a relatively well-fitting solution with fewer drawbacks in terms of growth parameter estimation and entropy issues. In all cases, model fit was enhanced when using a negative binomial distribution.

CONCLUSIONS

Substance use researchers would benefit from adopting a complimentary framework by exploring both LCMs and mixture approaches, in light of the relative strengths and weaknesses as identified. Additionally, the distribution of data should inform modelling decisions.

Correction to: Prenatal alcohol exposure and infant gross motor development: a prospective cohort study

Following publication of the original article [1], the authors opted to revise the first paragraph of the section "Characteristics associated with maternal drinking in pregnancy". Below is the updated version.