A Comparative Study of PDA and Non-PDA Autism: Exploring Distinctive Traits in Adults

Abstract

Pathological Demand Avoidance (PDA) is lifelong condition that is widely understood as a profile on the autism spectrum that has distinct characteristics beyond the broader set of traits associated with autism. This study, which was carried out in 2016, investigates the differences between PDA adults and those with a non-PDA autistic profile, focusing on 155 traits that emerged from a community-driven inquiry. Using data from 290 self-diagnosed PDA adults and 90 non-PDA autistic adults, this analysis explores significant differences between these groups, contributing to a clearer understanding of PDA as a unique profile within the autism spectrum.

Introduction

Pathological Demand Avoidance (PDA) is often considered an Autism Spectrum Condition (ASC), although it is distinguished by an extreme avoidance of everyday demands, heightened anxiety, and unique social strategies. Despite increasing recognition, particularly in children, research into adult PDA remains limited. To address this gap, the present study investigates the distinctiveness of the PDA profile compared to non-PDA autism by examining 155 traits identified by members of the adult PDA community. This study seeks to demonstrate the differences between the two groups and to contribute to the broader discourse on the need for greater recognition and understanding of PDA in adulthood.

Methods

This study originated from a large-scale community-driven investigation conducted in 2016. The research involved gathering trait suggestions from adult PDA individuals through online platforms, refining an initial list of 228 traits down to 155 that were considered distinctively PDA. The final study sample comprised 290 adults with self-diagnosed PDA and 90 non-PDA autistic adults.

The trait data were quantitatively analysed using a T-test to assess the statistical significance of differences between the two groups. Grace Trundle, a PhD student in Forensic Psychology at Nottingham University, conducted the statistical analysis.

Participants

The study included 380 participants, divided into two groups:
- PDA Group: 290 adults who self-identified as being PDA.
- Non-PDA Autistic Group: 90 adults who identified as autistic but did not exhibit the PDA profile.

Nearly 100% of the PDA participants were self-diagnosed, reflecting the current challenges in obtaining formal PDA diagnoses in adults.

Results

The T-test analysis revealed that 105 of the 155 traits (approximately 68%) showed significant differences between the PDA group and the non-PDA autistic group. These differences were most pronounced in specific domains, particularly in demand avoidance, anxiety, and social behaviours. Key findings are summarised below.

1. Demand Avoidance Traits (14 traits)  
   All 14 traits in this domain, such as "I avoid even potentially pleasurable and advantageous activities due to anxiety and demands," showed significant differences, with the PDA group scoring consistently higher than the non-PDA group.

2. Anxiety Traits (9 traits)  
   Similarly, all nine traits in this domain, including "I have self-medicated to reduce anxiety," demonstrated significant differences, with the PDA group reporting more intense experiences of anxiety compared to non-PDA individuals.

3. Social Traits (20 traits)  
   This group showed more variability. While there were significant differences in some traits, such as "I want to get on with people, but I never know what to say," two traits showed similarities between PDA and non-PDA individuals.

4. Attachment and Focus Traits (8 traits)  
   The PDA group scored higher on six of the eight traits, including "I have had obsessions about people," indicating differences in how individuals form attachments and focus on specific interests.

5. Freezing, Shutdown, Overload, and Jekyll & Hyde Behaviour Traits (4 traits)  
   All four traits in this group, such as "I have had Jekyll and Hyde behaviour," showed significant differences, further emphasising the emotional variability experienced by the PDA group.

6. Verbal Traits (12 traits)  
   While this group demonstrated a more even distribution of similarities and differences, traits like "I make up new names for people" highlighted unique characteristics of PDA individuals.

7. Emotional Lability Traits (6 traits)  
   All traits in this category, including "I have had over-the-top seeming emotional reactions," showed significant differences, with the PDA group exhibiting greater emotional variability compared to non-PDA autistics.

8. Control-Need Traits (9 traits)  
   This set of traits, such as "I feel a need to be in control," showed no similarities between the two groups, reinforcing the idea that control is a fundamental aspect of PDA behaviour.

9. Social Manipulation Traits (2 traits)  
   Both traits, including "I get confused as to why people tell me I am manipulative," showed significant differences, with PDA individuals reporting a greater sense of being misunderstood or mischaracterised in social interactions.

10. Employment Traits (8 traits)  
    In the context of employment, traits like "My perfectionism in work causes anxiety and makes it hard for me to keep up" revealed significant differences between the groups, with PDA adults experiencing more challenges in traditional work environments.

Discussion

The findings of this study demonstrate that PDA is distinct from non-PDA autism across a wide range of traits, particularly in domains associated with demand avoidance, anxiety, control, and emotional lability. The results suggest that PDA individuals experience higher levels of anxiety and a greater need for control, contributing to their characteristic avoidance behaviours. Social manipulation traits and employment-related challenges further distinguish the PDA profile.

The significant differences in demand avoidance and anxiety traits confirm the clinical picture of PDA as more than just an extension of general autistic traits. Instead, PDA presents as a separate neurotype with specific needs and characteristics, particularly in adulthood, where support and recognition are lacking.

Limitations

This study has several limitations. First, the reliance on self-reported data, particularly from self-diagnosed individuals, may introduce bias. Second, the lack of formal ethical approval and oversight, while understandable given the community-driven nature of the study, limits the generalisability of the findings. Third, the sample was drawn primarily from online communities, which may not represent the full diversity of the adult PDA population.

Conclusion

The results of this study provide strong evidence for the distinctiveness of the PDA profile compared to non-PDA autism, particularly in areas such as demand avoidance, anxiety, and emotional regulation. The findings highlight the need for greater recognition of PDA in adults and the importance of developing tailored interventions that address the unique challenges faced by this group. Future research should focus on formally diagnosing PDA in adults and further exploring the neurobiological underpinnings of this profile.

References

- Trundle, G., & Cat, S. (2019). Personal communication on T-test analysis of PDA traits data.
- Newson, E. (2003). Pathological Demand Avoidance Syndrome: An Autism Spectrum Condition.