Alongside the increased awareness about neurodiversity, late neurodivergent diagnoses have garnered more attention over the last few years (Stagg & Belcher, 2019). Many individuals who have unwittingly been living with neurodivergence for years have usually received multiple (mis)diagnoses and undergone treatment for an array of challenges varying from mood disorders, and relationship issues to substance use disorders by the time they finally receive the correct diagnosis (Stagg & Belcher, 2019). This seems to be especially true for females who tend to receive neurodivergent diagnoses even later than males (Leedham et al., 2019). Some studies have indicated that some neurodivergent conditions like ADHD can emerge after the cut-off ages (eg. during adolescence or early adulthood) included in current diagnostic guidelines (Asherson & Agnew-Blais, 2019).
Many neurodivergent diagnoses, such as ADHD and autism, are commonly characterised as “highly heritable” (Davidson et al., 2022), “early onset, pervasive and lifelong neurodevelopmental disorders” (Allely & Faccini, 2020, p. 2; Asherson & Agnew-Blais, 2019). This conceptualisation leads to an oversimplification of the complex interplay between environmental factors like adversity and trauma, and individual factors that include temperament and genetic propensities, as well as the overlapping epigenetic processes that might lead to a neurodivergent diagnosis. In addition, this oversimplification may impact decisions around which approaches should be used to address the issues or challenges accompanying a neurodivergent diagnosis (Melling & Smethurst, 2017).
Increasing evidence points to the importance of recognising the potential role trauma plays in the development, presentation, and progression of many cases of neurodivergence. Many of the behaviours or features that are considered typical of certain neurodivergent disorders – in particular, autism (Al-Attar & Worthington, 2024; Kerns et al., 2015), ADHD (Boodoo et al., 2022; Szymanski et al., 2011) and borderline personality disorder (Ditrich et al., 2021; Ferrer et al., 2016; Matthies & Philipsen, 2014; Weiner et al., 2019) are similar to those associated with having experienced early life trauma and childhood adversity (Al-Attar & Worthington, 2024). This has important implications as differentiating between trauma-related symptoms and those of neurodivergence is foundational to making appropriate treatment decisions (Al-Attar & Worthington, 2024; Ditrich et al., 2021; Kildahl et al., 2024). This also underlines the need for a paradigm shift away from the traditional, oversimplified conceptualisation of neurodivergent conditions as purely hereditary neurodevelopmental disorders. Using the correct lens or lenses to understand an individual’s difficulties is critical in determining the correct, and therefore the most effective, approach to help them live life to the fullest (Cox et al., 2019).
Individuals who have experienced trauma and early adversity are at a higher risk of having neurodevelopmental disorders like autism (Davidson et al., 2022) and ADHD (Boodoo et al., 2022; Szymanski et al., 2011). Stress, anxiety and trauma are an almost inevitable part of the lived experiences of neurodivergent individuals (Kildahl et al., 2024). As such, trauma symptoms are often perceived to be part of the neurodivergent disorder and remain unrecognised and unaddressed (Allely & Faccini, 2020). Research has also highlighted that neurodivergent individuals have a higher lifetime risk of experiencing trauma and developing symptoms in response to trauma (Davidson et al., 2022; Kerns et al., 2015; Kildahl et al., 2024). Added to this, neurodivergent individuals often experience trauma in ways that differ from our traditional, commonly-held understanding of trauma (Allely & Faccini, 2020; Kerns et al., 2015; Kidahl et al., 2024).
Trauma can also exacerbate the core symptoms and behaviours associated with neurodivergent conditions as well as increase the risk for other comorbid mental conditions (Allely & Faccini, 2020; Boodoo et al., 2022; Davidson et al., 2022; Szymanski et al., 2011). Neurodivergence characteristics or symptoms and trauma-related symptoms do not simply co-occur when both conditions are present but interact in complex ways that are often missed or misdiagnosed during clinician assessments (Boodoo et al., 2022; Ditrich et al., 2021; Kildahl, 2024). Kildahl and colleagues (2024) have documented how early traumatisation can increase the risk of misdiagnosing autism or other neurodivergent conditions as borderline personality disorder, which has a vastly different treatment approach and is associated with various negative connotations and stigmas. The same has been documented for ADHD (Ditrich et al., 2021).
Although the diagnosis of many neurodivergent disorders like autism entails a great deal of “diagnostic rigour”, their diagnosis is usually based solely on the interpretation of an individual’s life history and presenting symptoms and subsequently continues to present a diagnostic conundrum to clinicians (Al-Attar & Worthington, 2024; Davidson et al., 2022). In other words, making a neurodivergent diagnosis is hardly ever a clearcut process (Al-Attar & Worthington, 2024; Cox et al., 2019; Davidson et al., 2022; Kidahl et al., 2024). Neurodivergent conditions often co-occur with other mental health issues like trauma-related disorders, substance use disorders and mood disorders (e.g. depression and anxiety) (Al-Attar & Worthington, 2024; Allely & Faccini, 2020; Davidson et al., 2022). At the same time, many symptoms of neurodiversity diagnoses are non-specific and can also be indicative of other conditions, including complex trauma, that shares similar core symptoms or features (Al-Attar & Worthington, 2024; Asherson & Agnew-Blaise, 2019; Cox et al., 2019; Davidson et al., 2022; Ditrich et al., 2021; Kerns et al., 2015; Kildahl et al., 2024; Matthies & Philipsen, 2014; Melling & Smethurst, 2017). This means that the true cause/s of the presenting symptoms frequently goes/go unrecognised and untreated (Al-Attar & Worthington, 2024; Allely & Faccini, 2020).
Various authors (e.g. Al-Attar & Worthington, 2024) have pointed out how diagnostic assessments are more challenging in adults. Adults have frequently developed ways of managing or “masking” their neurodivergence symptoms (e.g. masking in autism or internalising symptoms in ADHD) (Cox et al., 2019; Weiner et al., 2019). Adding to the diagnostic challenges is the fact that neurodivergent conditions can present in a myriad of ways (Cox et al., 2017; Stagg & Belcher, 2019). According to Al-Attar & Worthington (2024), adult diagnostic assessments should always be underpinned by the knowledge that differentiating between potential diagnoses is a complex, time-consuming, resource-intensive process. This diagnostic difficulty could result in either overdiagnosis (false positives) or underdiagnosis (false negatives) (Al-Attar & Worthington, 2024).
Kidahl and colleagues (2024) suggest using a “multi-informant interdisciplinary assessment” approach in combination with a thorough review of previous case records and assessments, and in-depth history taking from various sources to help make the most appropriate diagnosis/diagnoses (Al-Attar & Worthington, 2024; Stagg & Belcher, 2019). Some tools have been developed to help differentiate certain neurodivergent diagnoses from other conditions (Allely & Faccini, 2020). The Coventry Grid for Adults is an example of such a tool (Cox et al., 2019; Melling & Smethurst, 2017). This Grid can help clinicians determine whether symptoms are likely to be due to complex trauma or autism (Cox et al., 2020). Although useful, tools like these should always be used with a fair amount of good clinical judgment (Allely & Faccini, 2020).
From a patient perspective, individuals often experience the diagnostic process as incredibly stressful (Leedham et al., 2019). Late diagnosis usually leads to a period of intense re-adjustment that involves accepting the diagnosis and its implications, as well as a shift in identity and self-concept (Leedham et al., 2019; Stagg & Belcher, 2019). Despite these difficulties, many individuals find that finally receiving the correct diagnosis is predominantly positive, usually accompanied by an increased sense of agency, self-acceptance, and self-compassion (Leedham et al., 2019; Stagg & Belcher, 2019).
A critical question remains: what came first, trauma or the neurodivergent condition? Regardless of this, it is important to understand that overlooking neurodivergence in a person who has “experienced early traumatisation may result in a risk that intervention and care are not appropriately adapted, which involves a risk of exacerbating trauma symptoms” (Kildahl et al., 2024). The same holds true for overlooking the consequences of traumatisation in neurodivergent individuals: not recognizing trauma symptoms could lead to inappropriate treatment decisions and the exacerbation of both the trauma and neurodivergence symptoms. The bottom line is that a bi-directional relationship exists between trauma-related disorders and neurodivergent conditions: “each predisposing to the development of the other, and worsening the severity of the other” (Boodoo et al., 2022). This is in line with the growing body of evidence that supports the notion that childhood trauma and adversity predispose individuals to the development of psychopathology (Felitti et al., 1998; Ferrer et al., 2016; Kerns et al., 2015).
References
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