Neuroanatomical Differences Associated With Anorexia Nervosa and Masking Behaviour in Autistic Individuals
Conditions: Autism, Anorexia Nervosa
Sponsor: University of Aberdeen

 
 
 
 
Neuroanatomical Differences Associated with Anorexia Nervosa and Masking Behaviour in 
Autistic Individuals: Protocol 
  
Version 2; 20/05/2025; IRAS: 349220 
Centre: Aberdeen  
 
 
 
 
 
    IRAS Project ID: 349220 
 
 
 
 
Neuroanatomical Differences Associated with Anorexia Nervosa and Masking 
Behaviour in Autistic Individuals 
 
 
 
 
 
Sponsor 
University of Aberdeen  
Funder 
Eating Disorders and Autism Collaborative (EDAC); 
UK Research and Innovation (UKRI) 
Chief Investigator 
Dr Michelle Sader 
Sponsor number 
2-081-24 
Version Number and Date 
Version 2, 20th May 2025 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
Neuroanatomical Differences Associated with Anorexia Nervosa and Masking Behaviour in 
Autistic Individuals: Protocol 
  
Version 2; 20/05/2025; IRAS: 349220 
 
PROTOCOL APPROVAL 
 
Neuroanatomical Differences Associated with Anorexia Nervosa and Masking 
Behaviour in Autistic Individuals 
 
 
Signatures 
By signing this document I am confirming that I have read, understood and 
approve the protocol for the above study. 
 
Chief Investigator 
 
Name:  
Dr Michelle Sader 
Postdoctoral Researcher 
Address: 
School of Medicine, Medical Sciences and Nutrition 
 
 
University of Aberdeen 
 
 
Lilian Sutton Building 
 
 
Foresterhill 
 
 
Aberdeen 
 
 
AB25 2ZD 
 
Telephone: 
01224 438356 
 
 
 
 
Fax: 
 
01224 438364 
E-mail:  
michelle.sader3@abdn.ac.uk 
__________________________ 
 
 
 
Sponsor 
 
Institution: 
University of Aberdeen  
Address: 
Research Governance Office 
 
 
Level 1 Health Sciences Building  
 
 
Foresterhill 
 
 
Aberdeen 
 
 
AB25 2ZB 
 
Telephone: 
01224 437221   
 

 
 
 
 
 
Neuroanatomical Differences Associated with Anorexia Nervosa and Masking Behaviour in Autistic 
Individuals: Protocol 
  
Version 2; 20/05/2025; IRAS: 349220 
LIST OF ABBREVIATIONS 
 
AN 
Anorexia Nervosa 
AQ 
Autism Quotient 
ASRS 
Adult Attention Deficit Hyperactivity Disorder Self-Report Scale 
CAT-Q 
Camouflaging Autistic Traits Questionnaire 
CI 
Chief Investigator 
CSOG 
Clinical Studies Oversight Group 
ED 
Eating Disorder 
EDAC 
Eating Disorder and Autism Collaborative 
EDE-Q 
Eating Disorder Examination Questionnaire 
EDS 
Eating Disorders Service 
HADS 
Hospital Anxiety and Depression Scale 
ITQ 
International Trauma questionnaire 
LSAS 
Leibowitz Social Anxiety Scale 
MQ 
Monotropism Questionnaire 
MRI 
Magnetic resonance imaging 
REC 
Research Ethics Committee 
ROI 
Region of Interest 
R&D 
Research and Development 
UKRI 
UK Research and Innovation 
WSAS 
Work and Social Adjustment Scale 

 
 
 
 
 
Neuroanatomical Differences Associated with Anorexia Nervosa and Masking Behaviour in Autistic 
Individuals: Protocol 
  
Version 2; 20/05/2025; IRAS: 349220 
PROTOCOL SUMMARY 
 
CONSIDERED 
FOR ENTRY 
Autistic individuals (either self-diagnosed or clinically diagnosed) 
as controls and Autistic individuals with a restrictive eating 
disorder (ED) such as anorexia nervosa (AN). Participants will 
be aged 25-45. 
TRIAL ENTRY 
Autistic individuals with and without AN will be screened for 
eligibility. Either online or written informed consent will be sought 
prior to the study. 
MAIN AIMS OF 
STUDY 
The main aim of the study is to determine whether there are 
neuroanatomical or functional differences between Autistic 
individuals relative to Autistic individuals with AN, and whether 
Autistic individuals with AN exhibit higher masking behaviour 
than Autistic individuals without AN. 
CO-ORDINATION 
Local and Overall: overseen by the Chief Investigator 
FUNDER 
EDAC; UKRI 
 
 
 

 
 
 
 
 
Neuroanatomical Differences Associated with Anorexia Nervosa and Masking Behaviour in Autistic 
Individuals: Protocol 
  
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ABSTRACT OF PROPOSED INVESTIGATION 
 
Autism is a neurodevelopmental condition and presents as a distinct neurotype, characterised 
by a wide range of social and behavioural differences, including divergences in cognitive 
thinking and methods of communication [1]. Autism shares significant behavioural features 
with restrictive eating disorders (EDs) such as anorexia nervosa (AN). Those with AN exhibit 
significantly elevated levels of Autistic characteristics, ranging between 2%-53% [2-4]. 
Importantly, a characteristic shown by some Autistic people is the presence of masking, a term 
describing a strategy used by Autistic people, whether conscious or unconscious, to ‘blend in’ 
with neurotypical peers [5]. While initially overlooked, it is now well-known that masking 
behaviour can produce detrimental effects on Autistic individuals’ mental health. The presence 
of masking behaviour has been associated with increased levels of physical and mental 
exhaustion [6,7], anxiety/depression [8], and importantly, an increased presence of EDs [5].  
 
The Eating Disorder and Autism Collaborative (EDAC) [9] used an arts-based method called 
Photovoice to capture the experiences of Autistic individuals with lived/living experience of an 
ED. Participants commented on the how an ED can serve as a means to mask or camouflage 
within a neurotypical world (e.g., an Autistic person may use restrictive eating or excessive 
exercise as a means with which to ‘fit in’ with their peers). Magnetic resonance imaging (MRI) 
research can assist in understanding which regions of the brain are associated with masking 
behaviour, and whether there are differences in brain function/structure in Autistic individuals 
with versus without an ED.  
 
This research aims to use a combination of brain imaging techniques and administration of 
scientifically validated questionnaires to investigate the relationship between autism, 
restrictive EDs, and masking. A 3T MRI scan will be used to investigate neuroanatomical and 
functional differences in Autistic individuals with AN (n=25) relative to healthy Autistic 
individuals (n=25), with questionnaires used to evaluate levels of Autistic characteristics, ED 
traits, as well as masking and social camouflage. Findings from this research aim to provide 
evidence towards the complexities of ED development and maintenance in Autistic individuals. 
 
  
 
 
 
 

 
 
 
 
 
Neuroanatomical Differences Associated with Anorexia Nervosa and Masking Behaviour in Autistic 
Individuals: Protocol 
  
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BACKGROUND 
 
Autism shares significant behavioural features with restrictive eating disorders (EDs), such as 
AN. Anorexia Nervosa (AN) is a severe and life-threatening eating disorder (ED) characterised 
by pathological fears of weight gain, a distorted body image, and extremely low body weight 
in relation to individual age and sex [1]. In Autistic people, masking has been associated with 
increased presentation of restrictive eating habits [5,7] and has been associated with poorer 
mental health. The presence of masking behaviour has been associated with increased levels 
of physical and mental exhaustion [6,7], anxiety, and depression [8]. 
 
Structural magnetic resonance imaging (MRI) research reports similarities in brain structure 
between those with AN and Autistic individuals, reporting differential structure of the amygdala 
[10,11], cerebellum [12,13], insula [14,15], cingulate cortex [14-16], as well as orbitofrontal 
and frontal cortex [15,16] in both groups. Shared differences extend to neuroanatomical 
parameters essential for brain development and connectivity [17], such as cortical thickness 
and surface area [18,19]. Further, there are no studies investigation structural correlates with 
masking behaviour, or distinct aspects of social camouflage such as masking, assimilation 
and compensation [20]. Further research is necessary to disentangle the complex relationship 
between Autistic characteristics and symptomatology associated with restrictive EDs. 
 
We believe that by further understanding the brain structure and function associated with ED 
symptomatology and masking behaviour in Autistic individuals can assist with the 
development of novel or tailored interventions for EDs in this community. 
 
STUDY AIMS AND OBJECTIVES 
 
The main aims of the study are: 
 
1) To examine whether Autistic individuals with AN exhibit differences in brain structure 
or function relative to Autistic individuals without AN.  
2) To determine whether Autistic individuals with AN exhibit higher masking behaviour 
than Autistic individuals without AN. 
3) To determine if there are associations between the levels of masking, ED 
symptomatology and brain structure in Autistic individuals.  
 
 
Primary Objective 
 
The primary objective of this study is to determine the relationship between masking, ED 
symptomatology and brain structure in Autistic individuals.  
 
 

 
 
 
 
 
Neuroanatomical Differences Associated with Anorexia Nervosa and Masking Behaviour in Autistic 
Individuals: Protocol 
  
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STUDY DESIGN 
 
 

 
 
 
 
 
Neuroanatomical Differences Associated with Anorexia Nervosa and Masking Behaviour in Autistic 
Individuals: Protocol 
  
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Abbreviations: AQ – Autism Spectrum Quotient; ARI – Aberdeen Royal Infirmary; ED – 
Eating Disorder; EDAC – Eating Disorders and Autism Collaborative;  
 
 
STUDY POPULATION 
 
The target population for this study includes 25 healthy Autistic individuals and 25 Autistic 
individuals with AN (aged 25-45). This study will be focusing on an adult sample to ensure 
individuals are able to articulate longstanding experiences of masking and social camouflage. 
Participants must also have no contraindications to MRI and have no history of trauma 
affecting the brain. 
 
INCLUSION CRITERIA 
Study Phase 1  
• 
Healthy Autistic Individuals (Autistic Controls) must: 
o Be aged 25-45 years 
o Be Autistic (clinically diagnosed and/or have an AQ-10 score of ≥6)  
o Be able to provide informed consent for the study 
o Be able to read, understand and respond to questionnaires in English 
o Have no history of an ED 
o Willing to have an MRI scan in Aberdeen 
• 
Autistic Individuals with AN (Autistic individuals with AN) must: 
o Be aged 25-45 years 
o Be Autistic (clinically diagnosed and/or have an AQ-10 score of ≥6) 
o Be able to provide informed consent to the study 
o Be able to read, understand and respond to questionnaires in English 
o Have a diagnosis of AN or a BMI of <18.5 
o Willing to have an MRI scan in Aberdeen 
 
EXCLUSION CRITERIA 
• 
Individuals are not eligible for the study if they: 
o Are aged <25 or >45 years  
o Are not Autistic or not clinically diagnosed as Autistic and have an AQ-10 
score of <6 
o Are diagnosed with an ED other than AN 
o Have a history of brain injury (e.g., stroke) 
o Be unable to provide informed consent for the study 
o Have contraindications to MRI scanning, such has implantable cardiac 
devices 
o Are unable to read, understand and respond to questionnaires in English 
o As participants will need to consent to the study and complete questionnaires 
by themselves, individuals with intellectual disability will be excluded from this 
study 
 
The Autism Spectrum Quotient (AQ-10) is a short questionnaire that primary care practitioners 
can use to test if a person should be referred for an autism assessment. We will use this as a 
screening tool to confirm the presence of Autistic traits in addition to the presence of a clinical 
diagnosis. 
 
 
 

 
 
 
 
 
Neuroanatomical Differences Associated with Anorexia Nervosa and Masking Behaviour in Autistic 
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PARTICIPANT SELECTION AND ENROLMENT 
 
IDENTIFYING PARTICIPANTS FOR ELIGIBILITY 
 
Individuals will be considered an Autistic control if they meet study eligibility criteria and have 
no previous or current history of an ED and have no contraindications to MRI. Potential 
participants will be considered an Autistic individual with an ED if they meet study eligibility 
criteria and have a current diagnosis of AN and have no contraindications to MRI. Clinical 
members of the Eating Disorders Services (EDS) at NHS Grampian will assist with recruitment 
by identifying patients who are Autistic and have AN. This will involve review of medical 
records by the direct care team. 
 
Once potential participants have been identified, a pre-recruitment screening survey will ask 
all participants to: 
1) Confirm they have received a clinical diagnosis of autism,  
2) Confirm if they are an Autistic individual with AN or not 
3) Complete the AQ-10 
4) List their height and weight 
5) Confirm if they have a previous history of trauma affecting the brain  
6) Confirm if they have any contraindications to MRI such as a heart pace-maker.  
 
For both groups, potentially eligible participants will be given a standard participant information 
sheet, and a simplified pictorial participant information sheet. If eligible to participate, all 
participants will also be given an MRI Information Pack to familiarise themselves with the on-
site location and process associated with an MRI scan. 
Participant who meets the inclusion criteria will be then asked whether they would prefer to 
receive their consent form and questionnaires electronically or complete them in-person just 
before their MRI scan. All participants will provide informed consent before completing the 
questionnaires and having their MRI scan. The MRI scan will be scheduled with the participant 
at their convenience. If the participant misses their study visit, they will be contacted by the 
research team to reschedule their scan. If 1) participants complete the pre-recruitment 
screener and are not eligible to participate or 2) participants are deemed eligible but the 
recruitment limit of n=50 has been reached, they will be informed that they will not be able to 
take part, and will be thanked for their time and interest. With permission, all participants’ GPs 
will be informed of their participation. 
 
 
Autistic Controls:  
 

 
 
 
 
 
Neuroanatomical Differences Associated with Anorexia Nervosa and Masking Behaviour in Autistic 
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Autistic controls will be recruited by advertising the study to third sector charities such as 
Autism & Neurodiversity North Scotland (A-ND) and Scottish Women’s Autism Network 
(SWAN) and by bulk email to the University of Aberdeen's Neurodiversity Network facilitated 
by leads of this network, and to members of the Eating Disorders and Autism Collaborative 
(EDAC) Research network who have previously notified their interest to participate in future 
autism-related research. Autistic controls who self-report an autism diagnosis will be 
confirmed as eligible to participate upon completion of the AQ-10 with a cut-off score of ≥6. 
All potential participants will complete the pre-recruitment screening survey to determine 
eligibility for the study. 
 
 
Recruitment via Third Sector Charities & The EDAC Network:  
Individuals from third sector charities and the EDAC network who have previously flagged that 
they would like to be contacted for future research will receive a participant invitation letter. 
Contact information of the research team will be included with the invitation letter to reach out 
to the research team if they have any questions. Individuals will also receive the participant 
information sheet (PIS) and a link to a participant pre-recruitment screening survey to 
determine study eligibility. If participants are deemed eligible to participate, they will receive 
the participant eligibility confirmation letter. Once individuals confirm their participation, the 
research team will correspond with the participant to schedule their study visit and MRI scan, 
and the participant will receive the MRI Information Pack. 
 
Recruitment via Third Sector Charities & the public:  
Autistic controls will also be recruited by advertising the study to the public through adverts, 
flyers, press releases and on social media. Recruitment via this approach will also include 
those from third sector charities who have not previously flagged that they would like to be 
contacted for future research. All advertising material will contain a QR code and a link which 
will redirect participants to the pre-recruitment screener to determine eligibility to participate in 
the study. If participants are deemed eligible to participate, they will receive the participant 
eligibility confirmation letter, and the participant information sheet (PIS). Once individuals have 
read the PIS and confirm their participation, the research team will correspond with the 
participant to schedule their study visit and MRI scan and the participant will receive the MRI 
information pack. 
 
 
 
Autistic Individuals with AN:  
 
Autistic Individuals with AN will be recruited through the EDS team within NHS Grampian, 
North East Eating Disorder Support (NEEDS), BEAT Eating Disorders, Autism & 
Neurodiversity North Scotland (A-ND) and Scottish Women’s Autism Network (SWAN) and by 
advertising the study to the public through adverts, flyers, press releases and on social media, 
and through members of the Eating Disorders and Autism Collaborative (EDAC) Research 
network who have previously notified their interest to participate in future eating disorder and 
autism related research.  
 
Recruitment via Third Sector Charities & The EDAC Network:  
Individuals from third sector charities and the EDAC network who have previously flagged that 
they would like to be contacted for future research will receive a participant invitation letter. 
Contact information of the research team will be included with the invitation letter to reach out 
to the research team if they have any questions. Individuals will also receive the PIS and a 
link to a participant pre-recruitment screening survey to determine study eligibility. If 

 
 
 
 
 
Neuroanatomical Differences Associated with Anorexia Nervosa and Masking Behaviour in Autistic 
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participants are deemed eligible to participate, they will receive the participant eligibility 
confirmation letter. Once individuals confirm their participation, the research team will 
correspond with the participant to schedule their study visit and MRI scan and the participant 
will receive the MRI Information Pack. 
 
Recruitment via Third Sector Charities & the public:  
Autistic patients will also be recruited by advertising the study to the public through adverts, 
flyers, press releases and on social media. Recruitment via this approach will also include 
those from third sector charities who have not previously flagged that they would like to be 
contacted for future research. All advertising material will contain a QR code and a link which 
will redirect participants to the pre-recruitment screener to determine eligibility to participate in 
the study. If participants are deemed eligible to participate, they will receive the participant 
eligibility confirmation letter, and the participant information sheet (PIS). Once individuals have 
read the PIS and confirm their participation, the research team will correspond with the 
participant to schedule their study visit and MRI scan and the participant will receive the MRI 
information pack. 
 
Recruitment via NHS Grampian: 
Clinicians in NHS Grampian who may be in contact with potentially eligible participants will be 
informed about the study and we will include posters for the study in public areas of the NHS 
and EDS. Potential participants will be identified by their clinical care team who will give them 
an electronic version of the participant invitation letter and the PIS at a routine clinical 
appointment. The information sheet will include researchers’ contact details to allow potential 
participants to contact the study team for further information or to indicate that they wish to 
participate in the study. Upon contacting the research team, individuals will receive a link to a 
participant pre-recruitment screening survey to determine study eligibility. If participants are 
deemed eligible to participate, they will receive the participant eligibility confirmation letter, and 
the participant information sheet (PIS) once more. Once individuals have read the PIS and 
confirm their participation, the research team will inform their GP of their participation, and 
correspond with the participant to schedule their study visit and MRI scan. The participant will 
also receive the MRI information pack. 
 
 
 
CONSENTING PARTICIPANTS 
 
Written and verbal explanation of the study will be provided. It will be clearly stated that the 
individual is free to withdraw from the study at any time for any reason without any prejudice 
to future care, and with no obligation to give the reason for withdrawal. The participant will 
have 2 weeks to consider taking part after receiving the participant eligibility confirmation letter. 
Participants will receive a follow-up email after one week of inactivity after the research team 
confirms their eligibility to take part in the research, to inform them that we will no longer 
consider them as an individual taking part in the study after a further week of inactivity. Under 
the condition with which participants withdraw from the study at this stage, all information 
collected through the screening form will be deleted. 
Written informed consent will be recorded with an electronic signature for those who choose 
to complete the questionnaires online or be recorded in-person in the Research MRI Centre 
in Aberdeen Royal Infirmary, if the individual chooses an in-person phase 1 session, by a 
researcher who has been trained to take informed consent. In both in-person and online 
settings, a copy of the completed consent form will be provided to the participant. Participants 

 
 
 
 
 
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will receive a total of 3 follow-up emails for each week of inactivity under the following 
conditions: 1) Participants opting to complete questionnaires in an online format who have yet 
to complete questionnaires; 2) Participants who completed questionnaires online who are 
asked to schedule their on-site visit for their MRI scan; 3) Participants who opt to complete 
questionnaires during their in-person visit to receive their MRI scan, who are asked to 
schedule their on-site visit. Under the condition with which participants withdraw from the study 
at this stage, all information collected through the screening form will be deleted. 
 
INELIGIBLE AND NON-RECRUITED PARTICIPANTS 
 
Only eligible individuals (following our pre-defined inclusion/exclusion criteria) will continue 
with the rest of the study procedures. Participants who are not eligible will not be recruited into 
the study. Individuals will complete a pre-recruitment screening survey. The link to this 
screening survey will be sent to potential participants who have expressed an interest in taking 
part in the study, and will be completed by all potential participants. If 1) participants complete 
the pre-recruitment screener and are not eligible to participate or 2) participants are deemed 
eligible but the recruitment limit of n=50 has been reached, they will be informed that they will 
not be able to take part, and will be thanked for their time and interest. Non-eligible individuals 
will also be made aware that the data they have provided and their contact details will be 
deleted. 
 
 
WITHDRAWAL PROCEDURES 
 
Participants are free to withdraw at any time during the study without having to give a reason. 
Should this occur, additional participants will be recruited until the required study target 
number is achieved. Data collected with consent would be retained and used in the study. No 
further data would be collected or any other research procedures carried out on the participant.  
 
STUDY ASSESSMENTS 
 
 
Questionnaires (either online or in-person): To be completed by all participants. 
• 
A demographic questionnaire that will be used to collect information on gender, age, 
height and weight, education level, employment status, time since and quality of autism 
diagnosis, co-occurring physical, mental health or psychological conditions, co-
occurring EDs and duration of ED illness, as well as current medication status. 
• 
The Eating Disorder Examination Questionnaire (EDE-Q; [21]) will be used to evaluate 
the presence, frequency and severity of eating disorder symptoms.  
• 
The 10-item Autism Spectrum Quotient (AQ-10; [22]) will be used to examine Autistic 
characteristics. The AQ-10 will also be used to screen for ingenuine participants. 
• 
Presence and levels of monotropism or selective interests will be evaluated using the 
Monotropism Questionnaire (MQ; [23]).  

 
 
 
 
 
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• 
The presence and level of masking behaviour will be measured using the 
Camouflaging Autistic Traits Questionnaire (CAT-Q; [20]). The CAT-Q contains three 
subscales that will be used in the proposed research: compensation (identifying means 
to circumvent social and communication differences associated with autism), 
assimilation (strategies implemented by Autistic individuals to ‘f it in’) and masking 
(hiding of the Autistic identity to conform with non-Autistic peers) [20].  
Additional questionnaires will be used to evaluate levels of mental health and wellbeing 
between.  
• 
Levels of depression and anxiety will be assessed using the Hospital Anxiety and 
Depression Scale (HADS; [24]). 
• 
Levels of co-occurring ADHD will be assessed using the Adult Attention Deficit 
Hyperactivity Disorder Self Report Scale (ASRS-v1.1; [25])  
• 
Levels of work and social adjustment will be assessed using the Work and Social 
Adjustment Scale (WSAS; [26]).  
• 
The International Trauma Questionnaire (ITQ; [27]) will be used to assess levels of 
psychological trauma.  
• 
Levels of social anxiety will be assessed using the Leibowitz Social Anxiety Scale 
(LSAS; [28]). 
Including informed consent, this is expected to take no longer than 2 hours and 10 minutes. 
Questionnaires can be completed in-person, or online via Qualtrics. Material within the online 
version and paper, in-person version are identical. 
 
MRI Assessment (in-person): The MRI scan will be conducted by a trained radiologist. 
Participants will be asked to lie in the MRI scanner while we collect 3D T1- and T2-weighted 
images, as well as resting state functional connectivity and diffusion tensor images.  
This will last approximately 45 minutes. The total amount of time spent on this study will be no 
longer than 3 hours. 
 
Post-Research Activities: Participants will receive the debrief sheet and will be compensated 
for their participation in this study in the form of a £30 Amazon or Love2Shop voucher, 
depending on their preference. After participation, individuals will also be asked to complete 
an optional anonymous feedback survey delivered via link on their experience participating in 
the study. 
 
POTENTIAL RISKS AND HAZARDS 
 
The described research involves the recruitment of Autistic individuals with and without AN.  
 
Risk of incidental findings from MRI scans: The MRI scans taken for this research project 
are not the same as those that would be needed for clinical diagnostic purposes. However, in 

 
 
 
 
 
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the event that the radiologist collecting the scan notices something of medical relevance, a 
CSOG clinician will inform the participant and their GP if the participant wishes for the research 
team to do this. A University clinician will then arrange for subsequent or further 
investigation/treatment, if needed. 
 
Risk of participant distress brought on by questionnaires: There is a chance participants 
may become distressed due to the nature of the questionnaire material, but this is unlikely 
since the questionnaires do not ask the individuals to recall specific events.  
• 
To mitigate risks of distress participants will be able to complete the questionnaires in 
an environment they are comfortable and familiar with if they choose.  
• 
The research team will provide information within the participant information sheet to 
direct participants to appropriate support services. 
 
Risk of participant distress due to the MRI environment: Autistic individuals may find the 
MRI scanning environment distressing due to the loud noise and bright lights associated with 
an MRI scan, as well as the style of interaction with the radiographers. Participants may find 
the MRI particularly distressing if they are prone to claustrophobia. To minimise possible 
distress, we will: 
• 
Ask participants if they have specific sensory sensitivities before their scan 
appointment is made so that adequate preparations can be made. 
• 
Provide participants with foam ear plugs as well as ear defenders. Participants will also 
be given the option of listening to their preferred music or sounds during the scan.  
• 
Dim the lights of the scanner room to provide a more comfortable environment for 
participants 
• 
Provide participants with an additional MRI information booklet and video recordings 
to familiarise them with the scanning location and the MRI process, as well as one-on-
one meetings with researchers to discuss the science and steps behind MRI if wanted. 
• 
Encourage participants to inform the research team in advance of their preferences for 
the level of interaction and physical contact during the scan. The research team and 
radiographers will work together to create procedures to minimise distress while 
maintaining participant safety. 
• 
Give the participant a call button to hold during their scan to alert the radiographers. 
Participants who express significant discomfort due to claustrophobia will be withdrawn 
from the study. 
 
Risks associated with use of MRI: Magnetic resonance imaging is a safe, non-invasive 
procedure and there are no known side effects to receiving an MRI scan. However, if there is 
any indication or potential with which an individual may be pregnant, they will not be 
considered eligible for the study. This information will be collected on the MRI safety screener 
before an individual receives their scan. 
 
SAMPLE SIZE 
 

 
 
 
 
 
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Sample size calculations are not appropriate for pilot studies. Our sample size of 25 for each 
group will ensure a spread of measurements to effectively estimate effect sizes and aid 
planning for future studies. 
 
DATA COLLECTION 
 
All research activities, methods of data collection and analysis associated with the proposed 
project will be conducted in accordance with the UK data protection laws. 
 
All online data 
collection for this project will be conducted using Qualtrics 
(https://www.qualtrics.com/en-gb), a secure online survey platform. Qualtrics will facilitate 
efficient data gathering, enabling participants to complete the questionnaires remotely with a 
variety of accessibility options and at their own convenience. If participants opt to complete 
questionnaires during their in-person visit, all data will be provided on paper, and will be 
transposed to an Excel spreadsheet securely stored on University of Aberdeen servers via a 
University OneDrive folder. Electronic consent forms will also be securely stored on a separate 
excel spreadsheet on a University OneDrive folder. The paper copies of both questionnaires 
and informed consent will be retained and stored securely in locked cabinets within room F04 
of the Lilian Sutton Building, made only accessible to the research team. Subject logs will also 
be retained as an Excel spreadsheet and stored on a separate secure University OneDrive 
folder. MRI scans will also be stored on a secure OneDrive folder, with statistics from scans 
transposed to an Excel spreadsheet.  Once participant MRI scans have been linked to 
participant questionnaire responses and their consent, research data will contain ID numbers 
for each participant which will be pseudoanonymised. The index linking pseudoanonymised 
IDs to participants’ names will be stored in a separate, secure excel spreadsheet within a 
University of Aberdeen OneDrive folder, made only accessible to the PI (Dr Michellle Sader). 
 
Data generated from this study will be kept for a minimum of 10 years and Dr Michelle Sader 
will act as custodian for the data. Contact details, upon provision of consent by participants, 
will be kept up to 5 years for the purposes of conducting future ethically-approved research. 
Otherwise they will be deleted at the end of the study. All data in electronic form will be retained 
and archived in secure University of Aberdeen servers. All data in physical or paper form will 
be retained in archived in a secure locked drawer associated with this study within Room F04 
of the Lilian Sutton Building at the University of Aberdeen. Only the named members of the 
research team (see Study Management and Oversight) will be able to access this data. 
 
The sponsor is responsible for ensuring that study data is archived appropriately. Documents 
will be archived in line with the Sponsor’s standard operating procedures. 
 
 
 
DATA PROTECTION 
 
All data collected through Qualtrics will be securely stored on servers compliant with the UK 
data protection laws and other international privacy standards, ensuring robust protection of 
personal information. Qualtrics adheres to strict data privacy policies, including data 
encryption, de-identification and anonymisation, both in transit and at rest. Qualtrics also has 
role-based access controls and ensures that only authorised members of the research team 
involved in the project will have access to the data to effectively safeguard participant data. 

 
 
 
 
 
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A member of the clinical care team will access medical records for the purposes of reviewing 
medical data relevant to participant eligibility, including age, date of birth, diagnosis of AN, 
diagnosis of Autism, and history of trauma affecting the brain. This information will only be 
seen by members of the individual’s direct care team. 
The chief investigator (CI) and study staff involved with this project will comply with the 
requirements of the UK Data Protection Laws. The HRA recommended wording to fulfil 
transparency requirements under the GDPR for health and care research has been included 
in the participant information sheet.  
The CI and study staff will also adhere, if appropriate, to the current version of the NHS 
Scotland Code of Practice on Protecting Patient Confidentiality. Access to collated participant 
data will be restricted to the CI and appropriate study staff. 
Computers used to collate the data will have limited access measures via usernames and 
passwords.  
Published results will not contain any personal data that could allow identification of individual 
participants. 
 
 
PROPOSED ANALYSES 
 
Methods of analysis will include assessment of demographic characteristics, brain structure 
and functional connectivity patterns, as well as calculation of generalised linear models 
between characteristics of masking and brain structure, as well as between characteristics of 
masking and symptoms of eating disorders. Pre-processing of MRI scans will utilise the 
FreeSurfer and fMRIprep software packages for brain structure and function respectively. 
Regions of interests (ROIs) will be derived from normalisation to the standard Desikan Killiany 
atlas. All statistical analyses will be conducted using the R Software. 
 
To achieve aim 1, structural differences of brain regions, both global and specific ROIs, will 
be reported as mean ± standard deviation (in mm^3) for each ROI between groups. For 
functional differences an independent component analysis approach will be used via the 
CONN toolbox on the statistical parametric mapping (SPM) software package, reported in Z-
scores for incorporated components, and means ± standard deviations of component 
loadings. Neuroimaging-based findings will also be accompanied by determining any group-
based differences across demographic and questionnaire-derived information.  
 
To achieve aim 2, mean differences on scores derived from the CAT-Q will be compared 
across groups and will be reported as mean ± standard deviation. 
 
To achieve aim 3, linear models will be used to evaluate associations between brain structure 
and function and domains of social camouflage (particularly masking behaviour), as well as 
associations between levels of masking and the presence of reported anxiety, depression, 
work and social adjustment and trauma. A 3-path mediation model will also assess whether 
ROI-based brain structure mediates the relationship between masking behaviour and ED 
symptomatology within the entire sample. 
 
The statistical analysis will be conducted by the Chief Investigator (CI; Dr Michelle Sader), and 
an Autistic peer researcher and PhD student (Caitlin Parsons). The statistical plan was 
developed by the CI and Dr Gordon Waiter. 

 
 
 
 
 
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MISSING DATA  
 
Where appropriate, missing data will be imputed to minimise the loss of data. Depending on 
the type of data missing, either simple imputation, multiple imputation will be used to 
minimise data loss. 
 
EARLY STOPPING 
 
No interim analysis is planned to inform early stopping. 
 
 
STUDY MANAGEMENT AND OVERSIGHT 
 
The CI will run the study on a day-to-day basis.  The study management committee will include 
Dr Michelle Sader (CI), Dr Gordon Waiter (Reader in biomedical imaging, University of 
Aberdeen), Dr Sam Aitcheson (Clinical Psychologist, NHS Grampian), Dr Madge Jackson 
(Psychologist, University of Aberdeen) and two Autistic peer researchers (Caitlin Parsons, 
Ellen Maloney). External oversight will include a meeting with EDAC, who has provided the 
funding for this research.  
 
The CI will be responsible for checking the CRFs for completeness, plausibility and 
consistency. However, this remains the overall responsibility of the CI. Any queries will be 
resolved by the CI or delegated member of the study team.  
 
A study-specific Delegation Log will be prepared, detailing the responsibilities of each member 
of staff working on the study.  
 
INSPECTION OF RECORDS 
 
The chief investigator (CI), PI and all institutions involved in the study shall permit study related 
monitoring, audits, and research ethical committee (REC) review. The CI agrees to allow the 
Sponsor or, representatives of the Sponsor, direct access to all study records and source 
documentation. 
 
 
GOOD CLINICAL PRACTICE 
 
Ethical conduct of the study 
 
The study will be conducted in accordance with the principles of good clinical practice. 
 
In addition to Sponsorship approval, a favorable ethical opinion will be obtained from the 
appropriate NHS research ethics committee (REC) and appropriate NHS research and 
development (R&D) approval(s) will be obtained prior to commencement of the study. 

 
 
 
 
 
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Confidentiality 
 
All results, questionnaires, reports, and other records will be identified in a manner designed 
to maintain participant confidentiality. All records will be kept in a secure storage area within 
the Lilian Sutton Building, University of Aberdeen, with access limited to study staff only. 
Clinical information will not be released without the written permission of the participant, except 
as necessary for monitoring and auditing by the Sponsor or its designee. The chief investigator 
(CI) and study staff involved with this study will not disclose or use for any purpose other than 
performance of the study, any data, record, or other unpublished, confidential information 
disclosed to those individuals for the purpose of the study. Prior written agreement from the 
Sponsor or its designee will be obtained for the disclosure of any said confidential information 
to other parties. 
 
The CI and study staff involved with this study will comply with the requirements of the UK 
data protection lawswith regards to the collection, storage, processing and disclosure of 
personal information and will uphold the Act’s core principles. The CI and study staff will also 
adhere, if appropriate, to the current version of the NHS Scotland Code of Practice on 
Protecting Patient Confidentiality. Access to collated participant data will be restricted to the 
CI and appropriate study staff. 
 
Computers used to collate the data will have limited access measures via user names and 
passwords. Published results will not contain any personal data that could allow identification 
of individual participants. 
 
 
 
INSURANCE AND INDEMNITY 
 
The University of Aberdeen is sponsoring the study. 
 
The University of Aberdeen holds and maintains policies of indemnity. These policies cover 
principals, partners, directors, employees and students of the University. 
 
 
 
 
STUDY CONDUCT RESPONSIBILITIES 
 
Protocol Amendments, Deviations, and Breaches 
 
The CI will seek approval for any amendments to the Protocol or other study documents from 
the Sponsor, and NHS R&D Office(s). Amendments to the protocol or other study docs will 
not be implemented without these approvals.  
 
In the event that a CI needs to deviate from the protocol, the nature of and reasons for the 
deviation will be recorded in the case reporting form, documented and submitted to the 
Sponsor. If this necessitates a subsequent protocol amendment, this will be submitted to the 

 
 
 
 
 
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Sponsor for approval and then to the appropriate REC and lead NHS R&D Office for review 
and approval.  
 
In the event that a serious breach of good clinical practice is suspected, this will be reported 
to the Sponsor immediately using the form “Breach Report Form”.  
 
 
Study Record Retention 
 
Archiving of study documents will be carried out as per University of Aberdeen guidelines.  
The sponsor standard operating procedure will be followed. Study documents will be archived 
in the Health Sciences Building archive. 
 
The sponsor is responsible for ensuring that trial data is archived appropriately.  Essential data 
shall be retained for a period of at least 10 years following close of study. Upon participants 
consenting their contact details will be kept for 5 years for the purposes of conducting future 
ethically approved research. 
 
 
End of Study 
 
The end of study is defined as the final participant’s visit. The Sponsor and the CI have the 
right at any time to terminate the study for clinical or administrative reasons.  
 
The end of the study will be reported to the Sponsor and REC within 90 days, or 15 days if the 
study is terminated prematurely. A summary report of the study will be provided to the Sponsor 
and appropriate REC within 1 year of the end of the study. 
 
 
 
REPORTING, PUBLICATION AND NOTIFICATION OF RESULTS 
 
Authorship Policy 
 
Ownership of the data arising from this study resides with the study team and their respective 
employers. On completion of the study, the study data will be analyzed and tabulated, and a 
clinical study report will be prepared.  
 
 
Publication 
 
The clinical study report will be used for publication and presentation at scientific meetings.  
Investigators have the right to publish orally or in writing the results of the study. 
 
Summaries of the results will also be made available to Investigators for dissemination within 
their clinical areas (where appropriate and according to their discretion).  
 
 
PEER REVIEW 
 

 
 
 
 
 
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Peer review of the initial study approach was performed by 3 peer reviewers. The final version 
of this study was reviewed by 2 external peer reviewers and 1 internal peer reviewer, who 
were Autistic individuals with lived or living experience of an ED. The specifics of the study 
protocol was reviewed by 3 internal peer reviewers with relevant expertise. 
 
 
 
 
 
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