Prenatal alcohol exposure and the early neurodevelopmental outcomes of children in a South African birth cohort study

Introduction: Over the last few decades, prenatal alcohol exposure (PAE) has been a major public health problem both globally and in low- to-middle-income countries (LMICs) such as South Africa. Pregnant women and new mothers are particularly vulnerable; and PAE may be associated with adverse child neurodevelopmental outcomes. However, few studies have explored the association of PAE, including risk factors, and subsequent neurodevelopmental trajectories over multiple timepoints in the early years. Given the high burden of PAE and associated risk factors, and the relative paucity of empirical data, further work in South African populations is warranted. This thesis aimed to investigate the association between PAE and early neurodevelopmental outcomes in the Drakenstein Child Health Study (DCHS), a South African birth cohort. The specific objectives included: 1. a systematic review on the available longitudinal studies exploring the impact of PAE on language, speech and communication development (Chapter 3 Manuscript 1); 2. an exploration of the association between PAE and motor, language and cognitive outcomes in infancy (Chapter 4- Manuscript 2); 3. an investigation of the association between PAE, including interactions of tobacco smoking exposure, and the neurodevelopmental trajectories (motor, language and cognitive outcomes) of children across the first 4 years of life (Chapter 5 Manuscript 3); 4. a comparison of the conversational turn-taking between mothers and their alcohol exposed children compared to those between mothers and their unexposed children (Chapter 6 Manuscript 4). Methods: This thesis included four publications, three of which present data from the DCHS. Pregnant women were enrolled from two public primary healthcare clinics, Mbekweni (a predominantly black African population) and TC Newman (a mixed-ancestry population), and more than 1000 mother-child dyads were followed longitudinally from birth through the first 5 years of life. For this study, both antenatal and postnatal maternal measures were used to assess moderate-to-severe levels of PAE. These measures included the (i) Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) antenatally, (ii) a retrospective alcohol questionnaire in the postnatal period at 3-6 weeks and/or 24 months testing age. At 6, 24 and 42 months, early neurodevelopmental outcomes were assessed using the Bayley-III Scales of Infant Development (BSID-III), the Kaufman Assessment Battery for Children (KABC-II) or the Peabody Picture Vocabulary Test (PPVT-IV). Conversational turn-taking in mother-child dyads was also assessed at 42 months testing age. Both univariate and multivariate analyses were used to analyse the data. Results: The findings of this thesisshowed that PAE was significantly associated with both fine motor (B=-3.30, 95%CI 0.06-0.46, p=0.001) and gross motor scores (B=-0.30, 95%CI 0.06-0.44 p=0.001) at 6 months (Chapter 4 Manuscript 2). Chapter 5 (Manuscript 3) showed that when accounting for the interaction between prenatal alcohol and tobacco smoking exposure, impaired fine motor functioning occurred up till 24 months (B=-12.59, 95%CI -21.98- -3.19, p=0.01), but these effects attenuated by 42 months. Significant interactions occurred between prenatal alcohol, including tobacco smoking exposure, and impaired receptive vocabulary (B=-2.49, 95%CI -5.24 -0.27, p=0.02) and cognitive functioning at 24 months (B=- 3.25, 95%CI -5.98- -0.52, p=0.02) (Chapter 5 Manuscript 3). Finally, when exploring conversational turn-taking in alcohol exposed mother-child dyads and unexposed dyads, PAE was significantly associated with conversational turn-taking i.e. child overlapping utterances (OR=3.25, CI 0.98-10.76, p=0.050) (Chapter 6 Manuscript 4). Conclusion: The associations of PAE with early neurodevelopmental outcomes shown here expand on the previous literature. Our findings reported that PAE may influence early neurodevelopmental outcomes, however, future studies should include additional longitudinal studies to replicate the findings, and ongoing follow-up of our own cohort may continue clarify the potential association of PAE and additional risk factors on later neurodevelopmental outcomes at school age and beyond. Effective alcohol programmes targeting pregnant women and interventions to address child developmental impairments in this vulnerable cohort are required

The effect of peer pressure and leisure boredom on substance use among adolescents in low-income communities in Cape Town

Magister Artium (Psychology) - MA(Psych)The adolescence period is a time of high risk for health and social problems such as substance use globally and in South Africa. Past research has shown that there is a need to investigate factors such as peer pressure, leisure boredom and substance use as they pose a threat to the social, psychological and physical wellbeing of adolescents in general. Thus, the overall aim of the study is to determine whether peer pressure and leisure boredom influence substance use among adolescents in low-income communities in Cape Town. Accordingly, the current study is guided by the theoretical framework of Jessor’s problem-behaviour theory. This exploratory study employed a correlational research design. The measurement tools included the Drug Use Disorders Identification Test, the Resistance to Peer Influence measure and the Leisure Boredom Scale. Non-probability sampling was used to select 296 adolescents between the ages 16 – 18 years from schools located in two low-income communities. Data analysis techniques included descriptive statistics, t-test, linear regression and multiple regression. Linear regression revealed that leisure boredom is not a significant predictor of substance use whereas peer pressure is a significant predictor of substance use. Multiple regression showed that the combined influence of peer pressure and leisure boredom predicted substance use, while peer pressure emerged as a stronger predictor than leisure boredom of substance use among adolescents. Gender did not moderate the relationship between peer pressure, leisure boredom and substance use among adolescent

Longitudinal relationship between adolescents' mental health, energy balance-related behavior, and anthropometric changes

Energy balance-related behaviors (EBRBs) are considered the immediate causes of adolescents' body weight increases, but adolescents have identified mental health as a contributor. Cross-sectional studies have reported associations between adolescents' mental health and obesity, but causal relationships and the role of EBRBs within this can only be established using longitudinal studies. This systematic review summarizes the findings of longitudinal studies investigating this relationship, in addition to the role of EBRB in the relationship. Multiple electronic databases were searched for longitudinal studies using keywords related to the adolescent population, mental health, EBRB, and body weight. In total, 1216 references were identified and screened based on previously defined eligibility criteria. Sixteen articles met the inclusion criteria. Most studies indicated that mental health-related measures like depression, anxiety, and body dissatisfaction were related to an increase in body weight later. As this review is focused on behavioral mediators, six studies reported associations between mental health—anthropometry dyad and EBRBs such as eating habits, screen time, physical activity, and sleep—as well as stressors like peer victimization. Future studies may focus on streamlining mental health measures and body weight outcomes to assess this relationship. Furthermore, more longitudinal investigations are needed to provide insight into the role of EBRBs in the mental health–body weight relationship during adolescence.publishedVersio

Understanding the dynamics emerging from the interplay among poor mental wellbeing, energy balance-related behaviors, and obesity prevalence in adolescents: A simulation-based study

Both obesity and poor mental wellbeing have a high prevalence in European youth. Adolescents in six countries identified mental wellbeing factors as main drivers of youth obesity through systems mapping. This study sought to (1) explore the dynamics of the interplay between poor mental wellbeing, energy balance-related behaviors, and adolescent overweight and obesity prevalence and (2) test the effect of intervention point scenarios to reduce adolescent obesity. Drawing on the youth-generated systems maps and a literature synthesis, we built a simulation model that represents the links from major feedback pathways for poor mental wellbeing to changes in dietary, physical activity, and sleep behaviors. The model was calibrated using survey data from Norway, expert input, and literature and shows a good fit between simulated behavior and available statistical data. The simulations indicate that adolescent mental wellbeing is harmed by socio-cultural pressures and stressors, which trigger reinforcing feedback mechanisms related to emotional/binge eating, lack of motivation to engage in physical activity, and sleep difficulty. Targeting a combination of intervention points that support a 25% reduction of pressure on body image and psychosocial stress showed potentially favorable effects on mental wellbeing—doubling on average for boys and girls and decreasing obesity prevalence by over 4%.publishedVersio

Adolescents' Perspectives on the Drivers of Obesity Using a Group Model Building Approach: A South African Perspective.

Overweight and obesity increase the risk of a range of poor physiological and psychosocial health outcomes. Previous work with well-defined cohorts has explored the determinants of obesity and employed various methods and measures; however, less is known on the broader societal drivers, beyond individual-level influences, using a systems framework with adolescents. The aim of this study was to explore the drivers of obesity from adolescents' perspectives using a systems approach through group model building in four South African schools. Group model building was used to generate 4 causal loop diagrams with 62 adolescents aged 16-18 years. These maps were merged into one final map, and the main themes were identified: (i) physical activity and social media use; (ii) physical activity, health-related morbidity, and socio-economic status; (iii) accessibility of unhealthy food and energy intake/body weight; (iv) psychological distress, body weight, and weight-related bullying; and (v) parental involvement and unhealthy food intake. Our study identified meaningful policy-relevant insights into the drivers of adolescent obesity, as described by the young people themselves in a South African context. This approach, both the process of construction and the final visualization, provides a basis for taking a novel approach to prevention and intervention recommendations for adolescent obesity

Adolescents’ Perspectives on the Drivers of Obesity Using a Group Model Building Approach: A South African Perspective

Overweight and obesity increase the risk of a range of poor physiological and psychosocial health outcomes. Previous work with well-defined cohorts has explored the determinants of obesity and employed various methods and measures; however, less is known on the broader societal drivers, beyond individual-level influences, using a systems framework with adolescents. The aim of this study was to explore the drivers of obesity from adolescents’ perspectives using a systems approach through group model building in four South African schools. Group model building was used to generate 4 causal loop diagrams with 62 adolescents aged 16–18 years. These maps were merged into one final map, and the main themes were identified: (i) physical activity and social media use; (ii) physical activity, health-related morbidity, and socio-economic status; (iii) accessibility of unhealthy food and energy intake/body weight; (iv) psychological distress, body weight, and weight-related bullying; and (v) parental involvement and unhealthy food intake. Our study identified meaningful policy-relevant insights into the drivers of adolescent obesity, as described by the young people themselves in a South African context. This approach, both the process of construction and the final visualization, provides a basis for taking a novel approach to prevention and intervention recommendations for adolescent obesity

Adolescents’ Perspectives on the Drivers of Obesity Using a Group Model Building Approach: A South African Perspective

Overweight and obesity increase the risk of a range of poor physiological and psychosocial health outcomes. Previous work with well-defined cohorts has explored the determinants of obesity and employed various methods and measures; however, less is known on the broader societal drivers, beyond individual-level influences, using a systems framework with adolescents. The aim of this study was to explore the drivers of obesity from adolescents’ perspectives using a systems approach through group model building in four South African schools. Group model building was used to generate 4 causal loop diagrams with 62 adolescents aged 16–18 years. These maps were merged into one final map, and the main themes were identified: (i) physical activity and social media use; (ii) physical activity, health-related morbidity, and socio-economic status; (iii) accessibility of unhealthy food and energy intake/body weight; (iv) psychological distress, body weight, and weight-related bullying; and (v) parental involvement and unhealthy food intake. Our study identified meaningful policy-relevant insights into the drivers of adolescent obesity, as described by the young people themselves in a South African context. This approach, both the process of construction and the final visualization, provides a basis for taking a novel approach to prevention and intervention recommendations for adolescent obesity

Adolescents’ Perspectives on the Drivers of Obesity Using a Group Model Building Approach: A South African Perspective

Overweight and obesity increase the risk of a range of poor physiological and psychosocial health outcomes. Previous work with well-defined cohorts has explored the determinants of obesity and employed various methods and measures; however, less is known on the broader societal drivers, beyond individual-level influences, using a systems framework with adolescents. The aim of this study was to explore the drivers of obesity from adolescents’ perspectives using a systems approach through group model building in four South African schools. Group model building was used to generate 4 causal loop diagrams with 62 adolescents aged 16–18 years. These maps were merged into one final map, and the main themes were identified: (i) physical activity and social media use; (ii) physical activity, health-related morbidity, and socio-economic status; (iii) accessibility of unhealthy food and energy intake/body weight; (iv) psychological distress, body weight, and weight-related bullying; and (v) parental involvement and unhealthy food intake. Our study identified meaningful policy-relevant insights into the drivers of adolescent obesity, as described by the young people themselves in a South African context. This approach, both the process of construction and the final visualization, provides a basis for taking a novel approach to prevention and intervention recommendations for adolescent obesity

Prenatal alcohol exposure is associated with early motor, but not language development in a South African cohort

Objective:To investigate the association of prenatal alcohol exposure (PAE) and early neurodevelopment in the first 2 years of life, adjusting for maternal sociodemographic and psychosocial factors, in the Drakenstein Child Health Study (DCHS), a South African birth cohort study.Methods:The DCHS comprises a population-based birth cohort of 1143 children, of which, a subsample completed the Bayley Scales of Infant Development-III (BSID-III) at 6 (n = 260) and 24 months of age (n = 734). A subset of alcohol exposed, and unexposed children was included in this analysis at age 6 months (n = 52 exposed; n = 104 unexposed) and 24 months (n = 92 exposed; n=184 unexposed). Multiple hierarchical regression was used to explore the associations of PAE with motor and language development.Results:PAE was significantly associated with decreased gross motor (OR = 0.16, 95%CI 0.06-0.44, p = 0.001) or fine motor (OR = 0.16, 95%CI 0.06-0.46, p = 0.001) functioning after adjusting for maternal sociodemographic and psychosocial factors at 6 months of age only. No significant effects were found in either receptive or expressive communication and cognitive outcomes at either time point.Conclusion:PAE has potentially important consequences for motor development in the first 2 years of life, a period during which the most rapid growth and maturation occurs. These findings highlight the importance of identifying high-risk families in order to provide preventive interventions, particularly in antenatal clinics and early intervention services. - 2020 Scandinavian College of Neuropsychopharmacology.Scopu