Potential comorbidity & diagnostic overlap between Complex Post-Traumatic Stress Disorder, Borderline Personality Disorder & Autism Spectrum Disorder

Full project title: "Potential comorbidity and diagnostic overlap between Complex Post-Traumatic Stress Disorder, Borderline Personality Disorder and Autism Spectrum Disorder: Considering trauma and damaging behaviours". The project represents novel interdisciplinary research that straddles research council remits, combining diagnostic specificity with individual and social impact.

The project adopts a multi-method approach incorporating advanced data skills and a novel AI-driven thematic analysis.

Complex PTSD (C-PTSD) affects around 7.7% of individuals, Autism Spectrum Disorder (ASD) impacts 1-2%, and Borderline Personality Disorder (BPD) up to 9.7% (Hyland et al, 2020; Roman-Urrestarazu et al, 2021; Ten Have et al, 2016). In these conditions, recent research highlights shared diagnostic components, shared behaviours and experiences, including the experience of trauma and the expression of damaging behaviours (e.g., self-injury, aggression).

Recognising the overlap between these conditions is crucial (Karatzias et al, 2023), particularly since those with multiple diagnoses face compounded emotional dysregulation, social challenges, and self-destructive behaviours (Cheney et al, 2023).

Surprisingly, despite these connections these diagnoses are not typically considered together in treatment pathways (Dell'Osso et al, 2023), and clinical unrest is growing because of the omission of shared components essential for formulation and treatment. For example, it is increasingly recognised that having C-PTSD and BPD may be indistinguishable (Jowett et al, 2020), and trauma is often overlooked in ASD (Carmassi et al, 2019).

Failing to acknowledge similarities ultimately limits treatment provision since clients are placed into treatment pathways unique to each diagnosis without sufficient justification.

Despite apparent shared elements across these conditions, no research has examined the extent to which diagnostic features collectively manifest across samples. Understanding this association is important for treatment and safety, including an appreciation of the impact on harm to self (self-injury, trauma) and harm to others (aggression). By understanding shared domains, treatment can focus on need rather than diagnostic label, leading to improved prognosis, better management of harm and enhanced life chances (Cheney et al, 2023).

No research has collectively addressed these contemporary areas of consideration, making this a particularly vibrant project for a PhD.

To address this, we will consider general population and clinical samples (patients, clinicians). The PhD student will benefit from access to all samples through placement at Ashworth Research Centre (ARC), a forensic mental health research unit within Ashworth Hospital, Mersey Care NHS Foundation Trust (MCFT), which is the largest NHS mental health trust in the UK.

The student will be co-supervised by a clinical lead (Professor Jane L. Ireland: MCFT, but who also holds a contract at UCLan), a consultant psychiatrist (Dr Alex Challinor: Non-HEI Lead, MCFT), and an ARC research lead, Dr Simon Chu (UCLan).

This project will have marked academic impact, both in terms of outputs (i.e., dissemination in 4* journals) and research informed impact in term of recommendations for clinical practice and clinical policy.