‘My whole role in the family was to be fine’: Exploring the lived experience of typically developing siblings of individuals with neurodevelopmental disability

Introduction

People who grew up with a sibling who had a disability often undertake complex emotional labour in family life, frequently downplaying their own needs to avoid familial conflict and maintain acceptance. Understanding these dynamics is essential in the Australian context, where disability policy and services shape everyday family roles and support. This paper focuses on typically developing (TD) adults who grew up with a sibling who had a neurodevelopmental disability (ND), examining lived experience and implications for practice in Australia. In line with the most recent discourse guidelines from People with Disability Australia (2022), the authors have used person-first language when referring to individuals with NDs, emphasising personhood rather than focusing on the impairment.

TD siblings are a significant population in Australia that are at risk of adverse outcomes. The American Psychiatric Association (2022) characterises ND as early-onset conditions that affect day-to-day functioning across personal, social, academic and/or occupational domains in varying severity. These conditions, such as intellectual disability, autism spectrum disorder and Down syndrome, are typically life-long and often co-occur. As of 2022, 5.7% of children aged 0–4 years and 13.5% of children aged 5–14 years have disability in Australia (Australian Bureau of Statistics (ABS), 2022). In Australia, two children were the most common family size from 2011 to 2021 across single and two-parent families (Australian Institute of Family Studies, 2023). Only one statistical report, published in 2008, specifically measured families with children with ND and found that these families tend to have more children than those without (ABS, 2008). Taken together, these statistics indicate that it could be common to have siblings within families caring for children with ND and that TD siblings are a significant portion of the population.

Within such families, the presence of ND can shape the developmental trajectories of TD siblings and influence their emotional wellbeing and social functioning. ND can contribute to unique developmental trajectories for TD siblings because they experience the complexities of their sibling’s co-occurring conditions and early life course adjustments (Kao et al., 2009; Wolfe et al., 2014). An Italian study by Sommantico et al. (2020) found that TD siblings of those with intellectual and developmental disability showed less positive sibling relationship attitudes, higher levels of depression and anxiety and lower levels of life satisfaction compared with those who had TD siblings. Additionally, recent evidence from an Australian study indicated that siblings are at greater risk of adverse psychological outcomes, such as clinically significant anxiety or depressive symptoms, as well as lower social wellbeing, compared with peers (Wolff et al., 2022). Collectively, these findings highlight that TD siblings are a vulnerable segment of the population who may be exposed to adverse outcomes. Understanding their lived experiences and the mechanisms that contribute to these experiences is therefore essential to inform interventions that improve their outcomes.

Australian disability care models have significantly evolved from mass institutionalisation to dispersed community supports. As per other colonial contexts, Australian institutions were initially used as congregate housing for individuals with various conditions, including disability, mental illness or physical illness (Coleborne, 2018; Raymond, 1976). Over time, psychiatric institutions recognised congenital mental deficiency [sic] as a distinct category, leading to the segregation of those with ND into separate institutions (Coleborne, 2018; Manning, 2009). New developments in psychiatric treatments, such as antipsychotic and antidepressant drugs, during the post-World War II period motivated the first notable recommendations for deinstitutionalisation and individualised at-home care (MacKinnon & Coleborne, 2003; Turner, 2004). By the 1970s, Australian disability rights activist groups pushed for the recognition of ability, better services and funding, and the right to live alongside those in the community (Carling-Jenkins, 2014). As a result, policies based on integration and normalisation prompted the Australian Government to close institutions and residents were moved to community-based group homes or returned to live with family members (MacKinnon & Coleborne, 2003; Manning, 2009; Wiesel & Bigby, 2015). In sum, the collective change in psychiatric treatment, societal attitudes and policy prompted the significant shift to community-based disability care that currently operates in Australia today. However, care models have major implications for how families manage caring for individuals with ND.

Deinstitutionalisation improved many aspects of life for people with disability but also introduced new challenges for families who assumed greater care responsibilities. Review papers suggest that those residing in community care settings experienced significant improvements in a range of quality-of-life measures versus those living in institutions (Chowdhury & Benson, 2011; Mansell & Beadle-Brown, 2010; McCarron et al., 2019; Young et al., 1998). However, by the 1970s, the closure of long-stay care facilities for individuals with disability exposed a critical shortage of replacement facilities, such as community-based group homes (MacKinnon & Coleborne, 2003). Historical data show that in 1981, 8.5% of Australian children with profound disability lived in care accommodation, compared with just 0.04% in 1998 (Australian Institute of Health and Welfare (AIHW), 2004). Furthermore, community care remained poorly defined by policy, resulting in a shared responsibility between formal and informal family supports (AIHW, 2004; MacKinnon & Coleborne, 2003). As a result, the lack of replacement services to foster a community-care model shifted more caring responsibilities onto families caring for children with ND.

The shortfall of community-based replacement services had a significant impact on family functioning. A 2007 study found that parents of people with severe disability experienced inadequate and poorly coordinated supports, which restricted social engagement and imposed financial burdens because caregiving limited paid work participation (Murray, 2007). National survey evidence from 2008 reported that 51% of primary carers felt they needed more support, 34% reported being worried or depressed and 18% reported having been diagnosed with a stress-related illness (AIHW, 2004). Importantly, TD siblings experienced ‘strained’ familial relationships, alongside 52% of Australian parents reporting losing touch or lacking time with other co-residing family members (ABS, 2008; AIHW, 2004). More recent data from the Carer Wellbeing Survey (2021–2022) confirmed that carers continue to report high levels of psychological distress, financial stress and reduced wellbeing, particularly in households lacking adequate external support (Schirmer et al., 2022; Schirmer & Riyanti, 2021). Taken together, these findings underscore how, despite policy reforms, unmet needs in family systems continue to shape the experiences of TD siblings, who remain vulnerable to stress and social isolation when external supports are insufficient.

In 2016, the National Disability Insurance Scheme (NDIS) was introduced in Australia to address long-standing shortcomings in disability support. Prior to its introduction, commissioned reports described disability services as fragmented, inconsistent and inadequate, leaving significant gaps for both individuals and families (Laragy & Fisher, 2020; Productivity Commission, 2011). Guided by Productivity Commission recommendations, the NDIS aimed to provide individualised planning that promoted choice and control, enabled private providers to stimulate service innovation, and expanded early intervention to reduce long-term costs (Laragy & Fisher, 2020; Productivity Commission, 2011). The scheme was rolled out nationally and became available to all eligible Australians by July 2020 (National Disability Insurance Agency, 2017, 2022). However, barriers still exist that limit access to support.

Several studies identify substantial barriers to accessing the NDIS and obtaining subsequent support. For instance, parent carers of children with disability reported limited knowledge of the NDIS, despite heavy media promotion of the scheme (Howard et al., 2015). Parents of children with ND also described experiencing significant delays in accessing support, with some families waiting up to 6 months to start planning their packages, which added to family stress (Boaden et al., 2021). Additionally, children presenting with similar needs received markedly different levels of assistance, differentially placing more caregiving responsibilities on some families (Boaden et al., 2021). Furthermore, families with fewer educational, financial and social resources faced particular disadvantage, because they often struggled to navigate the complexity of the NDIS system and were less able to self-fund services not covered by the scheme (Boaden et al., 2021). Similarly, families living in rural and regional areas and those from culturally and linguistically diverse backgrounds reported persistent challenges due to service shortages, geographic isolation and lack of accessible information (Boaden et al., 2021; Veli-Gold et al., 2023). National survey data reinforce these difficulties: by 2018, 57.4% of primary carers reported needing more support in their caring role compared with 46.4% in 2015 and 51% in 2008 (ABS, 2008, 2018). Therefore, despite the installation of the NDIS, carers consistently report unmet needs. Yet these studies continue to ignore the needs and experiences of TD siblings in this context.

Arguably, these gaps in support experienced by adult caregivers extend to TD siblings, who often assume caregiving roles and emotional responsibilities for their siblings with ND. Review studies suggest that TD siblings assume important roles throughout their sibling’s lifespan, including primary caregivers, advocates and/or legal representatives (Bigby et al., 2015; Múries-Cantán et al., 2023). For example, TD siblings report assuming roles as both caregivers and friends, providing primary (such as physical support with toileting and dressing) and secondary caregiving (such as parent respite), since childhood (Hall & Rossetti, 2018; Leedham et al., 2020). Some TD siblings described assuming these responsibilities out of a sense of duty and natural care for their siblings, but also described a burdensome experience marked by hypervigilance driven by their perceived need to protect them (Leedham et al., 2020). In Australian studies, the majority of TD siblings temporarily co-reside with their siblings with ND after the death of their parents before establishing a community-care residence (Bigby, 1998). Furthermore, in an Irish longitudinal study, up to 85% of TD sibling carers of siblings with ID reported feeling overwhelmed, and up to 52% experienced unmet needs by service provisions at any given time point (Leane, 2024). In sum, TD siblings play key lifelong roles in caring for individuals with ND, impacting their psychological wellbeing, yet are unrecognised as stakeholders and excluded from support. Importantly, it is arguable that TD siblings experience increased caregiving responsibilities and emotional strain alongside their adult caregivers when external supports are inadequate.

The dynamics between family members may be uniquely impacted by the presence of a child with ND, with impacts on TD sibling attachment. Attachment theory emphasises the effects of caregiving behaviours on infants and children that endure into adulthood (Ainsworth, 1978; Bowlby, 1984). Secure attachments form when caregivers are consistently available and responsive, whereas inconsistent caregiving can foster anxiety and negative self-concept that persist across the lifespan (Ainsworth, 1978; Bowlby, 1984; Mikulincer & Shaver, 2009). In families caring for children with ND, parents may provide inconsistent caregiving to their TD children while managing the additional demands of a child with complex needs. For example, a United Kingdom (UK) study found that TD adult siblings of individuals with ND reported significantly higher adult attachment-related anxiety and perceived parental caregiving more negatively compared with peers without a sibling with ND (O’Neill & Murray, 2016). Similarly, a recent United States study found that adult siblings of individuals with ND rated their attachment to caregivers as significantly poorer than those with TD siblings or no siblings (Shenoy et al., 2024). In contrast, an earlier Israeli study reported no significant differences in attachment styles between children with siblings with ND and those without (Levy-Wasser & Katz, 2004). Furthermore, Murray and O’Neill (2019) found that among adults, attachment-related anxiety correlated with negative perceptions of parental caregiving only in families without a sibling with ND, and not in families with a sibling with ND (Murray & O’Neill, 2019). O’Neill and Murray (2016) suggest that TD siblings of individuals with ND cognitively rationalised their experiences of inconsistent caregiving as a byproduct of the demands of their sibling’s ND. It should also be noted that, due to methodological inconsistencies across studies, it is difficult to draw firm conclusions from these results. Taken together, while the association between having a sibling with ND and insecure attachment is mixed, parental caregiving burden may undermine secure attachments of TD siblings, resulting in enduring adverse effects on mental health.

Despite being a significant population, TD siblings experience a lack of professional and social support, and their inclusion in research has been limited. In a UK study, TD siblings reported being overlooked in family-inclusive disability support settings (Tozer & Atkin, 2015). In a more recent UK thematic analysis, TD siblings reported feeling invisible during social interactions because others in their social environment focused on the wellbeing of their siblings with ND (Hanvey et al., 2022). This has contributed to the notion that TD siblings are ‘glass children’, reflecting how their needs are frequently overlooked or disregarded (Hanvey et al., 2022). Because TD siblings’ needs are often overlooked at both a family and institutional level, knowledge to inform better support is lacking. This study builds on such insights to examine the lived experiences of TD siblings in Australia, focusing on how family dynamics and systemic supports shape their socio-emotional outcomes. Specifically, it seeks to answer the question: What is the lived experience of adult TD siblings of individuals with ND in Australia?

Significance of the current study

Little qualitative research has been conducted in the Australian context since the national rollout of the NDIS. This is significant because the NDIS represents one of the most substantial reforms in the provision of disability support and has profoundly shaped the lives of families caring for individuals with ND. Understanding the TD sibling experience within this context is critical, because siblings’ roles are embedded in socio-cultural processes such as parent–child attachment and access to formal and informal resources.

This study is significant because it addresses the socio-cultural and emotional dimensions of the TD sibling experience in contemporary Australia. By employing Interpretative Phenomenological Analysis (IPA) within a CR framework, the study captures both the personal meanings siblings attribute to their experiences and the broader social and policy structures that shape them (Bhaskar, 2009; Smith et al., 2009). This dual focus provides nuanced insights into how TD siblings navigate family life, manage attachment processes and confront systemic barriers in disability support.

The contribution of this research is twofold. First, it advances theoretical and empirical understanding by situating the sibling experience in relation to major policy shifts such as the NDIS, highlighting the socio-political forces that influence lived experience. Second, it offers practical implications by identifying challenges that are often overlooked in policy and service design, particularly the lack of recognition of TD siblings’ needs within existing systems of support. In doing so, the study contributes to the growing body of evidence informing institutional reform and community practice aimed at promoting the wellbeing of TD siblings in Australia.

Methods

Research design

The combination of IPA within a critical realist (CR) framework is well-suited to the research question because it allows for close examination of participants’ lived experiences while also attending to the wider social and structural forces that shape those experiences.

IPA is an idiographic method concerned with how individuals make sense of their personal and relational worlds (Smith et al., 2009). It is underpinned by a double hermeneutic: participants are engaged in making sense of their experiences, while the researcher interprets these accounts to understand their meanings. This means knowledge is co-constructed, grounded in the subjective accounts of participants while acknowledging the interpretive role of the researcher.

CR provides a complementary framework by recognising that experiences do not occur in isolation but are influenced by enduring social structures such as policies, cultural norms and systems of support (Bhaskar, 2008; Danermark et al., 2019). In contrast to approaches that treat participants’ accounts as self-contained, CR assumes that there are real but often unobservable mechanisms that generate the patterns described. These include, for example, attachment processes within families or systemic barriers in access to disability support. CR thus integrates a realist ontology (the view that there is an objective reality that exists independently of our perceptions) with a constructivist epistemology (the view that our knowledge of this reality is shaped through social, cultural, and historical contexts) (Pilgrim, 2019).

CR also provides methodological tools for analysing unobservable mechanisms. Judgmental rationality involves weighing competing explanations to determine which best accounts for participants’ experiences (Pilgrim, 2019). For example, attachment processes may act as mechanisms influencing siblings’ long-term wellbeing, operating within broader family structures shaped by parental caregiving burden (Bowlby, 1984). The mechanisms–contexts–outcomes (MCO) heuristic clarifies how mechanisms interact with contexts to produce divergent outcomes (Pawson & Tilley, 1997). For instance, does adequate external support sustain secure attachments and account for mixed findings in attachment styles for TD siblings in the literature?

By combining IPA and CR, this study makes it possible to explore both the subjective meaning-making of participants and the broader causal mechanisms that frame these accounts. In practical terms, the analytic process first focused on participants’ detailed narratives of their sibling experiences (IPA) and then situated these accounts in relation to wider social structures and mechanisms such as policy, access to external support and family dynamics (CR). This dual focus allowed the study to capture both the immediacy of lived experience and the systemic conditions that shape it.

Researcher characteristics and reflexivity

In IPA, reflexivity refers to the researcher’s process of recognising and setting aside preconceptions that might bias interpretation (Smith et al., 2009). Therefore, because the primary researcher is a TD sibling of an individual with ND, the research may be susceptible to researcher bias yet may assist in the accurate interpretation of similar lived experiences. To mitigate this, reflexivity was embedded throughout the research process. Strategies included maintaining a reflexive journal and engaging with weekly collaborative meetings with the research team, all of whom were not siblings of individuals with ND. These practices enabled ongoing critical reflection and provided opportunities for the primary researcher’s interpretations to be examined, supported or constructively challenged, thereby enhancing the credibility and trustworthiness of the analysis (Finlay, 2009).

Sample and sampling

Our sample was recruited via social media and word-of-mouth. With prior approval from Siblings Australia (and after incorporating their feedback), a social media advertisement was placed on the SibChat Facebook group (a private group for TD siblings in Australia). Basic inclusion criteria required that participants be over 18 years old, have a sibling with ND, and have no ND themselves. Demographic information such as age and gender was collected to contextualise the sample and allow for reflexive consideration of participant diversity. While these characteristics were not used as primary analytic categories, they enabled greater sensitivity to the potential influence of individual differences across accounts. Recruitment strategies prioritised interviewing the first eight participants who fulfilled the selection criteria because this is typically the sample size required to attain data saturation (Smith et al., 2009). Indeed, we found that data saturation was reached after eight participants when no new insights emerged. Seven participants were recruited via the SibChat Facebook group, and one participant was recruited via word-of-mouth. Participants were aged 24 to 39 (M = 30.75, SD = 6.41) and had siblings with a range of ND diagnoses, seven of which had multiple diagnoses, including Down syndrome, speech dyspraxia, intellectual disability, autism spectrum disorder and attention-deficit hyperactivity disorder, varying from moderate to profound severity. Participants were asked to disclose gender identity; however, all participants responded with binary sex descriptors. Seven participants identified as female, and one participant identified as male. As described below, our interview schedule was piloted with the first three participants, and these were included in the sample of eight. Prior to participant recruitment and data collection, ethical approval for the research was granted by the Macquarie University Human Research Ethics Committee (Reference Number: 520241698957336) and informed consent was obtained from each participant before their interview.

Materials

A semi-structured interview schedule was developed in multiple stages. The initial version included 25 questions derived from prominent themes identified in the literature (Burnham Riosa et al., 2023; Hanvey et al., 2022; Múries-Cantán et al., 2023). This draft was refined in consultation with the research supervisor, external expert consultant, research assistants and other TD siblings. A pilot study, which included the first three interviewees, further informed the interview schedule in terms of question comprehension, suitability and scope. While these pilot interviews covered the main topics, some prompts were refined or added later; however, all interviews ultimately explored the same overarching themes. The feedback from this pilot study was then implemented into the final interview schedule of 17 questions that was used for the remainder of the study. Data from these three pilot interviews were included in the analysis because their content was rich; any new questions added afterward did not substantially alter the core topics discussed with pilot participants. The interview started with questions that focused on the individual’s experiences before moving on to investigate nuclear family dynamics, extended family, peer dynamics and then external support systems. The interview questions were emailed to all participants 48 hours before their allotted interview time, consistent with pilot study feedback, to allow time for reflection and reduce anxiety. The interview schedule was used flexibly to encourage participants to guide the direction of their responses, enabling them to prioritise issues most important to them. This approach ensured that while core themes were consistently explored across interviews, participants’ voices and lived experiences remained central to the process (Smith et al., 2009).

Data collection

Both in-person and online participation were offered to enhance sample diversity and participant comfort, which likely improved their openness during interviews. No notable differences were observed between in-person vs. online interviews. All interviews were conducted by the primary researcher, which were audio recorded, transcribed and manually checked for accuracy to enhance the credibility of the data. For this study, it was feasible for the researchers to conduct interviews at the university or online. One interview was conducted at the university campus, and seven were conducted online. Each interview lasted between 50 and 84 minutes (67 minutes on average), totalling approximately nine hours of audio for analysis.

Participants were anonymised using pseudonyms, which were chosen by the participants themselves. Allen and Wiles (2016) found this can foster a sense of ownership and rapport, thereby improving the quality of the data. Verbatim transcripts were sent back to each participant for member checking in order to clarify or retract their responses, enhancing the trustworthiness of the data (Birt et al., 2016). Every participant approved their transcripts for analysis, with no retractions, questions and/or queries. A brief research summary was shared with participants upon request via email. Participants also received a AUD$30 gift card as a thank you for their time and commitment to the study. This amount was deemed appropriate to compensate participants but not unduly coerce them into participating in the study (Gelinas et al., 2018).

Data analysis

The data analysis method is informed by the theoretical foundations of interpretative (also known as hermeneutic) phenomenology, which involves the interpretation of lived experiences, emphasising how individuals make sense of their experiences in their specific contexts (Neubauer et al., 2019). Thus, in analysing the data, we focused on how each participant made sense of their own experience within their family context. Analysis followed IPA guidelines where we immersed ourselves in each transcript through re-reading, noted initial insights, developed emergent themes and then looked for patterns across cases (Larkin & Thompson, 2011; Smith et al., 2009). Emergent themes were discussed and refined in collaboration with the research team to enhance credibility. As mentioned above, data saturation was achieved by the eighth interview, when no new insights were emerging. Quotes from interviews are presented with the participant’s pseudonym and transcript line numbers.

Findings

Consistent with IPA, the results and discussion are presented together. Due to space limitations, the focus here is on one of our master themes, which provides unique insights into family dynamics and attachment processes, with a brief outline of its related subordinate themes. Additional master themes identified during the analysis are beyond the scope of this paper.

Master theme: Family dynamics and relational impact

The master theme ‘Family dynamics and relational impact’ encapsulates how caring for an individual with ND affects family relationships, focusing on the emotional, relational and social impact of behaviours of concern and parental coping strategies. This theme also highlights how parental coping strategies contribute to TD siblings adopting the role of ‘the needless child’. We use ‘needless’ intentionally and critically to denote a role siblings reported internalising, not because they need less, but because they learned to present as if they had no needs to preserve parental connection and family equilibrium.

Parental strategies and coping

This superordinate theme explores the strategies parents employ to cope with the demands of caring for a child with ND. This theme describes how the intense needs of a child with ND often lead, albeit unintentionally, to the neglect of the emotional needs (i.e. acceptance and validation of emotions, comfort and consistency and reliability of caregiving) of TD siblings, a dynamic that contributes to the TD sibling’s development of ‘the needless child’ role. That is, TD siblings feel compelled to suppress or minimise their needs in order to maintain parental attachment and family harmony as parents grapple with the caregiving needs of their child with ND.

Learning the role of ‘the needless child’

Several TD siblings recall not having their emotional needs met by their parents throughout their childhood. Claudia described her needs as ‘somewhat neglected’ (355), while Laura noted they often ‘took a back seat’ (476) within the family. Mike reflected on the absence of emotional support from parents:

… my parents were physically there, like they were in the house, we all lived together, but when it was like at night, you know, lying in bed, feeling really terrible inside of myself, it was more kind of like me against the world and … there was definitely a lack of any, I guess psychological support on that end and, yeah, that that was definitely difficult. (Mike, 131–134)

Jess, whose experience contrasted with other study participants most, explained that her parents never made her feel ‘left behind’ (139):

I feel like when you’re older … you kind of look back and see, like, what your parents tried to protect you from when you were younger …. I was given a lot of attention and … it wasn’t all about her [my sister with ND], like there were always things to make sure, like, I was happy … (Jess, 147–152)

Jess’s use of the word ‘protect’ suggests that her parents sought to shield her from emotional or psychological distress. In contrast, other TD siblings described feeling compelled to conceal their own needs in order to maintain familial acceptance or avoid conflict. Claudia and Maya describe ‘hiding’ (Claudia, 351) their needs and displaying ‘a performance of being fine’ (Maya, 135). TD siblings believed that they did this to avoid being ‘rejected’ (Maya, 144) and to ‘survive’ (Wynona, 253). Claudia recalls her emotional response to not having her emotional needs met by her parents:

There was definitely, like, a time where someone had said something mean to me at school and I came up to my mum, and she was doing the laundry, and she was just like … I just don’t have time for this … I have to do this thing for [my sibling with ND]. And I just remember just internally shutting down. And that was like a key moment where I was like, I’m never going to my Mum about an issue again, and I wouldn’t have dared to say anything to my Dad anyway, but then it very much just became I’m not even gonna try. (343–348)

These accounts can be understood, through an attachment lens, as adaptive self-preservation strategies in which siblings manage their emotional expression in response to perceived caregiver availability or expectations (Ainsworth, 1978; Bowlby, 1984; Collier, 1994). This interpretation aligns with the broader analytic theme of emotional attunement and highlights how attachment processes function as causal mechanisms (Bhaskar, 2009).

Participants recognised how high parental caregiver burden led to their emotional neglect. Parents were described as being in ‘survival mode’ (Claudia, 301; Sabrina, 158) and ‘stretched thin’ (Mike, 66). Mike describes how his parents did not have a choice in neglecting his emotional needs due to inadequate external support:

They [my parents] didn’t really have a choice. This was kind of the world they were living in, where there was no real support for them. (61–62)

Furthermore, Maya linked her unmet needs, and the internalisation of the needless child role to her parents being overburdened:

I also wasn’t supposed to have needs, and if I did have needs, for example, if I got sick, it would be met with extreme annoyance from my mother because she was already so overburdened, and my being sick added to that. (152–154)

Jess, who had a positive caregiver experience, notes how she felt that her family were adequately supported by external support systems:

… she’s [my sister with ND has] always kind of been involved in that [external disability support programmes], like, throughout her life because they have programmes like kids, teens, young adults. So that’s always been good … and there’s this camp, like at the end of the year … and she [my sister with ND] goes on that and that’s kind of nice because like, me and my parents sometimes go away during that time. (317–322)

Using a CR lens, these findings suggest that attachment processes function as mechanisms that are shaped by contextual conditions, such as the level of parental burden and availability of external support (Pawson & Tilley, 1997). When support was lacking, TD siblings tended to adopt the needless child role, internalising patterns of emotional suppression that later contributed to adult anxiety and depression, even when TD siblings could rationalise emotional neglect as a byproduct of caregiver burden (Claudia, 351). By contrast, where external supports reduced caregiver burden, TD siblings maintained more secure attachment bonds. Taken together, these accounts illustrate how broader structural factors (like inadequate service provision, high parental burden and limited external support) interact with attachment processes to shape TD siblings’ developmental trajectories.

These findings underscore the need for policy and therapeutic interventions that recognise TD siblings as a group with genuine and ongoing needs. For practitioners, this means paying close attention to the ways in which attachment-related difficulties may emerge not from individual deficit but from systemic pressures. Supporting parents with adequate services, while explicitly recognising the needs of siblings, may help prevent the perpetuation of the ‘needless child’ role and reduce the risk of longer-term psychological difficulties. Considering this, TD siblings would benefit from adequate disability support, just as much as parents and individuals with ND, which would allow parents to foster secure attachments with all their children.

Conclusion

This study provides insight into how family dynamics, particularly those shaped by parental caregiving demands, contribute to the emotional positioning of TD siblings of individuals with ND. Participants described feeling compelled to suppress or minimise their own needs to meet perceived familial expectations, a strategy that may carry long-term psychological consequences. These findings demonstrate how psychological frameworks, including attachment theory, help illuminate the relational and developmental impacts of these roles. They also underscore the importance of situating TD sibling experiences within systemic contexts, where external supports and parental burden significantly shape outcomes.

Recognising TD siblings as key stakeholders in the disability support landscape invites a more inclusive approach to policy and practice, one that affirms their emotional needs and extends care frameworks to all members of the family. Integrating siblings into NDIS planning and supports (for example, by funding sibling peer groups or including sibling wellbeing in family support packages) could buffer emotional strain and improve outcomes. For clinicians, the findings highlight the importance of exploring sibling dynamics during family assessments and recognising that attachment processes and mental health outcomes may be shaped by systemic caregiving burdens. Supporting parents with adequate services, while explicitly validating the needs of TD siblings, may help prevent the adoption of the needless child role.

Limitations and strengths of the study

Several limitations of this study should be acknowledged. First, seven of the eight participants were sourced from the Siblings Australia Facebook group, SibChat, which may bias the sample toward individuals with more challenging experiences. Second, inferences made about social structures and causal mechanisms to explain the experiences of the participants may be subject to researcher bias, despite reflexive practices, which may impact the credibility of the results (Bhaskar, 2008; Danermark et al., 2019; Finlay, 2009). While the findings are not broadly generalisable due to the idiographic focus, they offer theoretical insights that may transfer to similar contexts (Smith et al., 2009). Third, the interview schedule was refined after three pilot interviews, meaning not all participants were asked exactly the same questions. However, all interviews covered the core topics, mitigating this issue. Lastly, most participants were female, so brother perspectives are underrepresented.

Despite these limitations, the study contributes to the literature by highlighting the experiential aspects of being a TD sibling and the social structures and causal mechanisms that shape that experience. Additionally, using CR, we applied pre-existing theory to explain patterns in participants’ experiences and to illustrate how the same mechanisms can lead to different outcomes depending on each TD sibling’s context (Pawson & Tilley, 1997; Pilgrim, 2019). Using these theoretical frameworks generated a rich and deep understanding of the lived experience of TD siblings within the socio-cultural context of Australia. In doing so, it highlighted possible areas of intervention that can improve their outcomes.

Theoretical implications

This study utilised an IPA within a CR framework. This pluralist methodology allowed for a holistic analysis of the TD sibling’s lived experiences. An IPA explored the participants’ subjective lived experience, while critical realism uncovered the objective yet unobservable causal mechanisms and social structures that shaped that experience (Bhaskar, 2008; Smith et al., 2009). The IPA revealed the complex emotional experiences that TD siblings navigated throughout their lives and the subjective meanings they attached to those experiences (Smith et al., 2009). Using a CR framework (namely, judgemental rationality and MCO), this study applied pre-existing theory that best explained the patterns of subjective experiences described by the participants and how certain mechanisms (such as parental caregiver burden) deliver differing outcomes (Pawson & Tilley, 1997; Pilgrim, 2019). Using these two theoretical frameworks generated a rich and deep understanding of the lived experience of TD siblings within the socio-cultural context of Australia and highlights possible areas of intervention that can improve their outcomes.

Real-world impact

This study highlights the often-overlooked experiences of siblings of individuals with neurodevelopmental disability in Australia, showing how parental caregiving burden and systemic gaps in disability support shape siblings’ emotional development and mental health. The current study’s findings highlight several ways to improve the outcomes of TD siblings of individuals with ND. There is currently no national policy, including the NDIS, that aims to safeguard the wellbeing of TD siblings within families caring for children with ND. As TD siblings experience their own unique challenges related to ND and are impacted by the adequacy of disability support provisions, this study suggests that TD siblings would benefit from institutional recognition within NDIS policy. This study recommends that TD siblings be systematically included in disability supports that increase their capacity to manage their own unique challenges related to ND. This institutional recognition will generate greater societal awareness of the TD sibling experience, arguably increasing parental awareness of their needs and improving the adequacy of formal psychological supports that currently fail to understand the lifelong complexities of their situations. Additionally, this study highlights how common psychological and social theories map onto the TD sibling experience, which is especially relevant for those working with TD siblings in therapeutic contexts.

Future research

Future research should examine the prevalence of insecure attachment and psychopathology in this population. It should also investigate how these outcomes relate to risk factors identified in this study, such as parental caregiver burden and access to external disability support. This would help determine whether the current findings are generalisable to the broader TD sibling population. Longitudinal studies would help clarify causal pathways between childhood experiences and adult outcomes. Qualitative work in diverse cultural and policy contexts could assess how TD siblings’ needs vary across settings. Such research would not only inform tailored interventions but also contribute to broader public health debates about the ripple effects of disability support gaps on family systems. Finally, such research could underscore the wider public health impact of insufficient disability support on sibling mental health. Additionally, future studies could investigate differences in TD sibling experiences by sibling gender, birth order or type of ND diagnosis to tailor support effectively. Further qualitative research could also explore TD sibling experiences in other cultural contexts or across different life stages to see how support needs evolve. Importantly, future studies should also critically interrogate how siblings come to adopt the ‘needless child’ role, and how service design might disrupt this dynamic by affirming siblings’ needs as legitimate.

Conflicts of interest

The authors report there are no competing interests to declare.

Data availability

The participants of this study did not give written consent for their data to be shared publicly, so due to the sensitive nature of the research supporting data is not available.