Avoiding Misdiagnosis: Overlap Between Autism and Personality Disorders

Autism spectrum disorder and personality disorders: What methods do physicians employ for differential diagnosis?

Autism 2023, Volume 27, Issue 6, Pages 1847–1850
© The Author(s) 2023
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Clare S. Allely, Emma Woodhouse, and Raja A.S. Mukherjee

Summary
While it is acknowledged that autism spectrum disorder (ASD) and personality disorders (PDs) have some commonalities, the precise nature of their association remains ambiguous. The overlapping symptomatology and intricacies in developmental trajectories of ASD and PDs might result in diagnostic ambiguity and difficulties in establishing differential diagnoses. The characteristics of ASD and PD can be erroneously assigned, resulting in misdiagnosis or overlooked diagnoses in individuals diagnosed with ASD, thereby affecting treatment strategies. Given the complexity of distinguishing between ASD and PD, which has significant consequences for treatment strategies, it has been posited that further insights and indicators are necessary to enhance diagnostic processes. An essential necessity exists to investigate the processes by which doctors arrive at diagnostic determinations and the obstacles they encounter in reaching diagnostic findings. In areas of overlap, it is crucial to examine how doctors interpret and assign specific traits within the framework of ASD and/or PD diagnosis.

Abstract
It is widely acknowledged that autism spectrum disorder (ASD) and personality disorders (PDs) have several similar characteristics. The precise nature of the link between ASD and the PDs remains unclear. The overlapping symptomatology of Autism Spectrum Disorder (ASD) and Personality Disorders (PDs) can result in diagnostic ambiguity, since characteristics of ASD and PD may be misattributed, thereby resulting in the misdiagnosis of ASD patients. Given the complexity of distinguishing between ASD and PD, it has been contended that further insights and indicators are necessary to enhance diagnostic processes. There is an urgent necessity to investigate, firstly, the processes by which doctors arrive at diagnostic conclusions, and secondly, the strategies to successfully address the problems and difficulties encountered during decision-making. Furthermore, in instances with evident overlap, how can physicians determine the appropriate categories to accurately comprehend the individual?

Keywords: ASD, Autism Spectrum Disorder, personality disorders

The precise link between ASD and personality disorders (PDs) is still ambiguous (Lugnegård et al., 2012). Although many times of developmental origin have been proposed, the effects of postnatal influences on early developmental pathways remain uncertain. The DSM-5 indicates that personality disorders often emerge between adolescent to early adulthood, whereas autism spectrum disorder manifests in early infancy (refer to Alafia & Manjula, 2020; Velikonja et al., 2019). Limited research has investigated personality characteristics or personality disorders in individuals with autism (e.g., Kanai et al., 2011; Ozonoff et al., 2005; Soderstrom et al., 2002). Existing research reveals that individuals diagnosed with ASD display a distinct cluster of personality characteristics. Hofvander et al. (2009) discovered that 42 out of 62 (68%) patients diagnosed with ASD met the DSM diagnostic criteria for at least one personality disorder. Lugnegård et al. (2012) discovered that 26 out of 54 patients diagnosed with ASD fulfilled the diagnostic criteria for at least one personality disorder. Notably, there is a paucity of research examining personality characteristics or personality pathology in Autism Spectrum Disorder (ASD) relative to particular personality disorders (PDs). Inquiries emerge on the reasons behind this phenomenon. Hrdlicka and Dudova (2013) proposed a potential developmental transition between Autism Spectrum Disorder (ASD) and Personality Disorder (PD).

ASD and PD have several shared variables due to their phenomenological similarities. The intersection between personality disorders and autism spectrum disorder is particularly pronounced in the domains of social communication and interaction. Both include challenges in establishing and sustaining connections, leading to dysfunction across several areas of functioning, including occupational, interpersonal, and social domains (APA, 2013). Dudas et al. (2017) observed that the clinical overlap between ASD and PDs may lead to diagnostic ambiguity, particularly in women (Lugnegård et al., 2012). Clinical observations have revealed some parallels between Autism Spectrum Disorder (ASD) and Borderline Personality Disorder (BPD), including issues with identity, extreme anger, self-destructive behavior, and significant difficulties in interpersonal interactions (e.g., Fitzgerald, 2005; Pelletier, 1998). Borderline Personality Disorder (BPD) can obscure autistic characteristics and may potentially occur as a comorbidity, resulting in potential misdiagnosis (Takara et al., 2015).

Concentrating on certain symptoms and traits without considering the comprehensive clinical context may result in misdiagnosis. For instance, traits such as flat intonation, minimal facial expression variation, and diminished emotional gestures—often linked to ASD—may also be interpreted as 'emotional coldness, detachment, or flattened affectivity,' a criterion for Schizoid Personality Disorder. This exemplifies the potential for misattribution of symptoms between ASD and personality disorders.

Although there are significant parallels in symptoms between ASD and specific PDs (Lugnegård et al., 2012), it is crucial to acknowledge the distinctions in these manifestations. These distinctions are essential in the evaluation of differential diagnosis. Both ASD and PD diagnoses need extensive and enduring behavioral patterns that result in functional deficits. Although certain symptoms of ASD and PD may overlap, it is crucial to assess the comprehensive clinical presentation across the lifespan. This encompasses a targeted observational assessment for Autism Spectrum Disorder (e.g., the Autism Diagnostic Observation Schedule, ADOS-2; Lord et al., 2012), which examines the nuanced and clinical quality of present behaviors, general observations from care professionals, a comprehensive developmental history (incorporating input from a parent or family member when feasible), and the evaluation of differential diagnoses within a multidisciplinary team.

The clustering of certain symptoms and traits may assist doctors in determining whether the presentation is more accurately attributed to ASD, PD, or both. A diagnosis of ASD according to DSM-5 and ICD-10 necessitates the presence of confined and repetitive behaviors and interests. This include preoccupations, restricted interests, challenges with modest alterations to routine, ritualistic behaviors, stereotyped or repeated motor actions, use of items and words, and variations in sensory processing. Although some limited and repetitive behaviors may be evident in particular personality disorder diagnoses (e.g., Obsessive-Compulsive/Anankastic Personality Disorder), these behaviors are not characteristic of other personality disorders (such as Borderline, Antisocial, or Schizoid Personality Disorders). For individuals who have become 'institutionalised' by routines in inpatient and secure environments, it is crucial to ascertain whether the adherence to routine existed prior to their admission to that specific setting and whether it has been a consistent characteristic of their behavior since early childhood. Prior to assigning specific traits to ASD or PD, it is essential to evaluate the whole presentation, symptom clusters, and developmental trajectory.

Autism Spectrum Disorder (ASD) and Personality Disorder (PD) are clinical diagnoses that can guide therapeutic strategies; nevertheless, it is essential to take into account the individual's distinct strengths, challenges, and requirements during clinical assessments and treatment planning. Instruments such as the International Personality Disorder Examination (IPDE, Loranger, 1999; Loranger & Mombour, 1996), ADOS-2, and the Autism Diagnostic Interview – Revised (ADI-R, Lord et al., 1994) can significantly contribute to the assessment process; however, it is crucial to recognize that they are designed to enhance clinical reasoning rather than deliver definitive diagnoses. Qualitative information must be meticulously evaluated, and in certain instances, clinical judgment may supersede quantitative scores and thresholds. Recently, Gordon et al. (2020) released guidelines for doctors to assist in distinguishing between ASD and BPD. The guidelines represent a significant advancement. The authors indicate that the guidelines were formulated based on existing theoretical literature and their clinical expertise, rather than empirical data. It is crucial to emphasize that there is a paucity of theoretical material now accessible. To our knowledge, no empirical research have so far examined the deficiencies of existing diagnostic and screening techniques in distinguishing between individuals with ASD (Kenny et al., 2016) and PD.

Given the complexity of distinguishing between ASD and PD, it has been posited that further markers are necessary to enhance diagnostic processes. Distinguishing individuals diagnosed with ASD from those with PDs is crucial for prognosis assessment and therapeutic decision-making (Strunz et al., 2015). Considering the aforementioned obstacles related to diagnosing personality disorders and autism spectrum disorder, particularly the prevalence of misdiagnosis, it is essential to investigate how these complexity are perceived by clinicians engaged in the diagnostic procedures. Research can provide insights into how practitioners would behave in accordance with diagnostic guides. Even in that context, variations in interpretation will persist, as evidenced by psychiatric studies throughout the years. The assessment or interpretation of an individual's phenomenology frequently varies across specialists, resulting in diverse interpretations of phenomenology and its associated qualities. Consequently, case discussions occur often among many clinicians to get a consensus on diagnosis. By comprehending the existing practices of physicians about ASD and PDs, we may ascertain whether the populations are same and more effectively differentiate between the two.

Comprehending clinicians' methodologies in addressing diagnostic complexity related to ASD and/or PD, while ensuring professionals receive enough training, is crucial. It is essential to analyze potential issues, such as distinguishing inherent variances in brain development from psychosocial challenges. Ultimately, while our emphasis has been on ASD and PD, it is imperative to examine the broader neurodevelopmental disorders that intersect with ASD, such as attention-deficit/hyperactivity disorder (ADHD). Traits often linked to ADHD, like impulsivity and emotional dysregulation, frequently intersect with symptoms of certain personality disorders. The co-occurrence of ASD and ADHD can further complicate the differential diagnosis process.

Financial Support
The author(s) did not receive any financial assistance for the research, authoring, or publishing of this work.

ORCID identifiers
Clare S. Allely – https://orcid.org/0000-0001-7640-9505
Raja AS Mukherjee – https://orcid.org/0000-0002-2171-928X

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