Many autistic adults face additional and significant barriers to diagnosis, with detrimental impacts.
Autistic adults who were undiagnosed in childhood have reported a range of negative experiences associated with their missed diagnosis, including social isolation, diminished self-understanding, and inadequate mental healthcare (Huang Y. et al, 2020; Leedham A. et al, 2020). However, for many late-diagnosed autistic adults, receiving an autism diagnosis brings a sense of relief, self-acceptance, and improved management of mental and physical health conditions (Lilley R. et al, 2022; Stagg SD & Belcher H, 2019).
In recent years, researchers have sought to explore the barriers to autism diagnosis, particularly among adults. Inconsistent autism training among mental health professionals may contribute to autistic traits being missed or dismissed (Crane L. et al, 2019), especially in historically under-diagnosed groups such as women and gender minorities. Additionally, overlapping traits between autism and conditions such as Borderline Personality Disorder (BPD in DSM-5, also known as Emotionally Unstable Personality Disorder in ICD-10) may contribute to misdiagnosis (May T. et al, 2021) in these cohorts.
Tamilson, Eccles and Shaw (2024) explore the experiences of autistic adults who had previously received a diagnosis of BPD, to better understand the impacts of misdiagnosis.
Missed diagnosis, or misdiagnosis, can have detrimental impacts on anyone, but especially on autistic adults.
Methods
This was an interpretive phenomenological study, framed within a social constructionist paradigm – an appropriate approach for addressing the exploratory research questions.
Purposive sampling via social media advertising was used to recruit participants who were: English-speaking autistic adults (including self-diagnosed) with a previous diagnosis of BPD, located in the United Kingdom.
One-to-one semi-structured interviews were conducted and audio-recorded via Microsoft Teams. Interview questions were informed by the researchers’ knowledge, a literature review, and individuals with relevant lived experience.
Interpretive phenomenological analysis (IPA) was used to generate detailed accounts of participants’ individual experiences, which were then consolidated into group experiential themes.
Results
Ten participants were interviewed (mean age = 34; 90% female, 10% questioning gender identity). The average age for receiving a BPD diagnosis was 22, and 29 for autism.
Ten group experiential themes were constructed and sequenced to reflect the journey of participants, starting in early life:
- Struggles in early years
- Participants all felt different from others and struggled to ‘fit in’ from an early age.
- However, none were diagnosed as autistic in childhood.
- Missed diagnosis of autism
- Many felt their autism was missed because of gender bias and poor knowledge about autism among mental health professionals.
- A recipe for misdiagnosis
- Participants felt that mental health professionals readily misattributed their traits and experiences (e.g., self-harm, ‘autistic shutdowns’, symptoms of childhood trauma) to BPD.
- This impeded recognition of their autistic traits.
- Receiving a diagnosis of BPD
- BPD felt like a “lazy diagnosis” (P5) that was given “too readily” (P1).
- No uniform methods were identified, in the assigning of this diagnosis – but participants felt powerless to disagree with a diagnosis.
- It overshadowed their individual needs and prevented appropriate care.
- Disadvantages of receiving a BPD diagnosis
- Strong social stigma towards BPD, deeply impacted participants’ self-perception, creating feelings of shame in addition to dissonance with their lived understanding of themselves.
- All participants experienced difficulties accessing adequate mental healthcare after the diagnosis.
- When services were accessed, they could be harmful and traumatic: participants became healthcare-avoidant, feeling dehumanised and stigmatised.
- Autism diagnosis
- Participants who sought an autism diagnosis faced barriers, including professionals not believing them, delayed referrals, and long wait times.
- Diagnosis with autism was associated with expressions of relief, and self-perception that was not tied to BPD.
- Positive aspects of autism diagnosis
- In contrast with the process of seeking diagnosis, receiving an autism diagnosis was described as positively “life-changing” (P2).
- Benefits included better treatment from others, self-acceptance, improved mental health, and appropriate accommodations in education and employment.
- Participants expressed experiencing less ‘blame’ for their lived experience, and more validated in expressing their health concerns.
- Negative aspects of autism diagnosis
- Although participants overall experienced their autism diagnosis more favourably than their BPD diagnosis, they still reported experience of social stigma and ableism in education and healthcare settings.
- Reflections on diagnostic labelling
- Most paricipants considered their BPD diagnosis was incorrect, rather than concurrent with autism.
- However, BPD was described as a difficult label to formally “get rid of” (P10).
- Helping others
- Participants expressed a growth mindset arising from their autism diagnosis, and reported their roles as advocates for others questioning their diagnosis, encouraging persistence when pursuing an autism diagnosis.
Although both Autism and BPD diagnosis led to experiences of stigma, participants identified with autism exclusively, not concurrent BPD.
Conclusions
By exploring the experiences of autistic adults previously, and often incorrectly, diagnosed with BPD, this study revealed the substantial negative impacts of missed diagnosis and misdiagnosis.
Participants’ felt their autistic differences were mischaracterised as BPD by mental health professionals due to gender bias, stereotypes and inadequate knowledge about autism. Receiving a diagnosis of BPD had profound negative impacts on their self-concept, reinforced by stigma and traumatic healthcare experiences.
Receiving an eventual autism diagnosis was described as ‘life-changing,’ enabling self-acceptance and appropriate support. Tamilson and colleagues (2024) “call for improved autism training for psychiatrists” to prevent misdiagnosis of autistic adults.
This study adds to the call for psychiatrists to have greater diagnostic training for autism in adults.
Strengths and limitations
Strengths
This study responds to a clear community need and considers benefits for the autistic community from the outset.
Strengths of the study include:
- Consistency in the chosen research paradigm (social constructionism), methodology (interpretive phenomenology and analytical approach (IPA)); all of which are appropriate for addressing the exploratory research question.
- The positionality of the research team was well described and includes relevant personal and professional expertise.
- Study conceptualisation and development of the topic guide were informed by individuals with lived experience.
- The sampling approach and sample size were suitable for IPA.
The inclusion of self-diagnosed autistic participants was commendable – as this acknowledges the barriers to formal diagnosis experienced by a cohort traditionally excluded from research, whose views are highly relevant to the study aims and findings.
The resulting themes are detailed, consistently supported by illustrative quotes, and complemented by figures that creatively represent the data. The poem in Table 2 humanises the data in a way that is rare to see in research.
Limitations
Tamilson and colleagues acknowledge that the data collection approach may have been inaccessible to autistic people who are non-speaking or uncomfortable with the social demands of an online interview, meaning that the unique perspectives of such individuals were likely excluded.
It appears that alternative interview approaches were not offered, which may be a logistical decision. However, the authors do not describe any other efforts to improve inclusivity, which creates a missed opportunity for minoritised communities who they identify are more at risk of receiving a misdiagnosis. Guidelines to promote inclusion of autistic adults in research (Nicolaidis C. et al, 2019) suggest accommodations such as:
- Sharing the interview schedule in advance.
- Providing alternative interview formats (e.g., email or text message).
- Allowing a support person to be present.
These accommodations can remove barriers to participation and improve representation of diverse autistic voices in research, and are a recommendation for researchers to consider in future projects.
Clearly, with a 90% female sample, the researchers could have done more to include a broader range of people in this study.
As this project was conducted through self-selected survey participation, not much is known regarding the diagnostic processes undergone by participants in relation to either BPD or autism diagnosis, or how they can be improved. It would be of benefit for a future study to also seek experiential qualitative data regarding mental health professionals’ perspectives on diagnostic procedures and training in the same geographical area to see if cross-comparison or standardisation is feasible, keeping in mind the more diverse population coming to seeking autism diagnoses in adulthood.
This study captures the lived experience of some autistic adults. The experience of providers remains to be captured.
Implications for practice
Missed diagnosis and misdiagnosis of autistic adults has garnered substantial attention lately. Research exploring experiences of late autism diagnosis has proliferated in the past ten years (e.g., Huang Y. et al, 2020; Leedham A. et al, 2020; Lilley R. et al, 2022; Lupindo BM. et al, 2023; Stagg SD & Belcher H, 2019), and trending social media content about lived experience of late- or self-diagnosis has brought this topic into public discourse (Krouse L, 2022).
Each late-diagnosed autistic person will have a unique perspective and experience regarding their diagnosis. However, the above literature reveals some common insights, which mirror the findings of this study by Tamilson and colleagues, as well as my own experience as a late-diagnosed autistic woman:
- Undiagnosed autistic people often feel different to others from a young age, but may not understand why. This can be detrimental to their mental health and self-perception.
- Many have felt their autistic traits were overlooked or dismissed by mental health professionals, preventing timely diagnosis and access to necessary care.
- Receiving an autism diagnosis often brings a sense of validation, relief, community, self-acceptance, and access to accommodations and appropriate care.
This study by Tamilson and colleagues extends upon the existing literature by providing valuable new insights into the specific harms associated with misdiagnosis of BPD among autistic adults. Though future cross-sectional research is needed to determine the prevalence of this misdiagnosis and its associated harms, I believe the implications of these findings for clinical practice cannot be understated. Research on this topic consistently indicates the necessity of better autism training among mental health professionals, however, this study illuminates the specific ways in which gender bias and stereotyping of certain diagnostic labels can influence misdiagnosis and perpetuate harm.
As such, training should not only aim to improve clinical knowledge, but it must also challenge biases and stereotypes regarding autism and diagnoses with overlapping traits, like BPD. Promoting the variability inherent in autism, including among women and gender minorities, may support more nuanced approaches to differential diagnosis, preventing mislabelling and inadequate care.
Though the rationale for this study is framed through the perspective of social justice for the autistic community, the implications for those diagnosed with BPD and other conditions feel equally evident, as many participants felt that they were neglected and mistreated in mental health settings due to structural stigma towards BPD. Irrespective of their diagnostic label, everyone deserves access to affirming mental healthcare.
Stigma is often a significant barrier to accessing timely and appropriate mental healthcare, which should be available to all.
Statement of interests
None to declare.
Links
Primary paper
Tamilson B, Eccles JA, & Shaw SCK. (2024) The experiences of autistic adults who were previously diagnosed with borderline or emotionally unstable personality disorder: A phenomenological study. Autism 2024 1-14.
Other references
Crane L, Davidson I, Prosser R, & Pellicano E. (2019) Understanding psychiatrists’ knowledge, attitudes and experiences in identifying and supporting their patients on the autism spectrum: Online survey. BJPsych Open 5(3) e33.
Huang Y, Arnold SR, Foley KR, & Trollor JN. (2020) Diagnosis of autism in adulthood: A scoping review. Autism 24(6),1311-1327.
Krouse L. (2022 August 17) Women are discovering they may have ADHD or be on the autism spectrum from trending TikTok videos. Women’s Health.
Leedham A, Thompson AR, Smith R, & Freeth M. (2020) ‘I was exhausted trying to figure it out’: The experiences of females receiving an autism diagnosis in middle to late adulthood. Autism 24(1) 135-146.
Lilley R, Lawson W, Hall G, Mahony J, Clapham H, Heyworth M, Arnold SR, Trollor JN, Yudell M, & Pellicano E. (2022) ‘A way to be me’: Autobiographical reflections of autistic adults diagnosed in mid-to-late adulthood. Autism 26(6) 1395-1408.
Lupindo BM, Maw A, & Shabalala N. (2023) Late diagnosis of autism: Exploring experiences of males diagnosed with autism in adulthood. Current Psychology 42 24181–24197.
May T, Pilkington PD, Younan R, & Williams K. (2021) Overlap of autism spectrum disorder and borderline personality disorder: A systematic review and meta-analysis. Autism Research 14(12) 2688-2710.
Nicolaidis C, Raymaker D, Kapp SK, et al. (2025) The AASPIRE practice-based guidelines for the inclusion of autistic adults in research as co-researchers and study participants. Autism: The International Journal of Research and Practice 23(8) 2007-2019.
Stagg SD, & Belcher H. (2019) Living with autism without knowing: Receiving a diagnosis in later life. Health Psychology and Behavioral Medicine 7(1) 348–361.
