Transition from childhood to adolescence in neurodivergent girls

Abstract

Adolescent girls with a diagnosis of autism, ADHD, and/or developmental co-ordination disorder (DCD) have worse mental health than their neurotypical girl peers and boys with the same diagnoses. These girls are called neurodivergent here, though neurodivergence includes a broader range of diagnoses. This mental health gap between neurodivergent boys and girls begins and/or widens during adolescence. This PhD thesis aims to understand the factors which make the transition from childhood to adolescence (11-14 years) particularly challenging for neurodivergent girls. A transdiagnostic approach is adopted to explore the reasons why this is the case for three diagnostic categories (autism, ADHD and DCD) and to reflect the common co-occurrence of these diagnoses. It adopts an intersectional framework, meaning it aims to understand the factors specific to being a neurodivergent girl.

Chapter 1 summarises the extant literature on mental health in neurodivergent girls and explores the reasons for why they are a vulnerable group for high rates of anxiety and depression. Research has shown that girls and women have worse mental health than men in the general population and that this gender gap begins during adolescence. Similarly, neurodivergent young people have worse mental health than neurotypical young people. The poor mental health outcomes for neurodivergent girls could be because of these additive risk factors. There could also be intersectional risk factors associated with the specific experience of being a girl and neurodivergent. Chapter 1 explores the extant literature on risk factors associated with being a girl, being a neurodivergent young person, and the intersectional risk factors of being both.

This thesis took a participatory methods approach to explore the intersectional risk factors associated with the poor mental health of neurodivergent girls. Chapter 2 explains the participatory methods framework adopted for this PhD, the co-production conducted for the project and the impact it had on the project. A stakeholder group of fifteen neurodivergent women was recruited along with a co-production co-ordinator. Co-production took part in three phases; Firstly, workshops and interviews were held with stakeholders to establish their research priorities facilitated by the question What are the girl specific challenges of transitioning from a child to a teenager? In phase 2, the proposed research questions for the thesis were presented to the stakeholders and feedback was collected. In phase 3, consultation was conducted with four neurodivergent teenagers to improve the accessibility of the project. From this co-production work, two intersectional risk factors were selected to focus on: camouflaging and timing of puberty.

Camouflaging is the conscious or unconscious suppression or projection of aspects of self and identity and the use of non-native cognitive or social strategies. It is not a female-specific issue, anyone may do it, but it seems girls camouflage more than boys. Chapter 3 aimed to understand camouflaging in 119 neurodivergent and neurotypical girls aged 11-14 years. Findings showed that, relative to the neurotypical girls, the neurodivergent girls had already started using camouflaging strategies by this age. Moreover, a strong relationship between camouflaging and anxiety and depression symptoms is evident at this age.

Chapter 4 explores the question of when camouflaging develops during childhood and adolescence. The same sample from Chapter 3 took part in timepoint 2 in a longitudinal study 10 months later. Camouflaging scores and mental health scores were stable over this timespan. This chapter discusses the future of longitudinal studies in camouflaging research and points out some methodological and theoretical challenges.

Chapter 5 explores the second intersectional risk factor, timing of puberty measured by timing of menarche (first period). Previous research has shown in the general population, earlier puberty is linked with poor mental health outcomes for girls and boys, but this effect may be more pronounced in girls. This exploratory study found no difference in the mean timing of first period between the neurodivergent group and the neurotypical group (M = 11.65) although there was a significant difference in the variances, where the neurodivergent girls had greater variability in their timing of menarche (earlier and later). This finding suggests neurodivergent girls may be more prone to early and late puberty. The relationship with menarche and mental health in girls is discussed in this chapter.

In conclusion, this thesis showed two predictors of poor mental health (high camouflaging levels and early/late puberty) are more likely to be experienced by neurodivergent girls compared to neurotypical girls, contributing to our understanding of why they are a high risk group for anxiety and depression. These two risk factors exist alongside the social and executive function challenges that become more acute during adolescence, as well as girl-specific challenges which emerge/intensify during adolescence, such as lack of understanding from secondary schools, increased vulnerability to developing an eating disorder, delayed or misdiagnosis, and sexual exploitation. This thesis highlights the importance of taking an intersectional approach when aiming to understand the specific experiences of neurodivergent girls and the relationship with poor mental health outcomes.