Background: Phenotypic similarities exist between autism-related experiences and anxiety (especially social anxiety and obsessive-compulsive disorder [OCD]), making it difficult for autistic people to self-report their experiences using existing measures developed for nonautistic adults. We examined whether clarifications aiming to tease out autism-related experiences from social anxiety or OCD in self-report questionnaires would influence autistic and nonautistic participants' ratings. Methods: Two autistic consultants and two experienced clinicians were consulted to develop item clarifications aiming to disentangle autistic from anxiety experiences for two questionnaires: the Social Anxiety Questionnaire (SAQ) and the Padua Inventory (PI) for OCD. Autistic adults (n = 50) and nonautistic university students with higher (n = 81) and lower autistic traits (ATs; n = 104) completed the original questionnaire followed by the clarified questionnaire items online. Results: For social anxiety, there were few significant differences between the original and clarified item and total SAQ scores. For OCD, participants reported significantly lower scores for the OCD-clarified PI items than for the original items and the autism-clarified items. Larger original-clarified PI mean item differences were noted in items describing repetitive behaviors, "obsessional" thoughts, and contamination fears. Similar patterns of differences were found in autistic and nonautistic participants with higher and lower ATs, but differences were often larger in the autistic group. Conclusion: The SAQ in its original form appears to be an appropriate measure for autistic people to self-report social anxiety. However, autistic people appeared to complete the original PI items to reflect, to some extent, their autism-related experiences, rather than the originally intended OCD symptoms. Thus, the original OCD self-report ratings were inflated using the PI. Professionals should therefore clarify the intended meanings of different items of the PI to ensure more accurate and relevant ratings of OCD symptoms in autistic people. Lay summary Why was this study done? Autistic people and people with higher autistic traits (ATs) often experience higher rates of anxiety. Anxiety measures developed for the general population may not be appropriate or accurate for measuring anxiety in autistic people. We investigated whether clarifying items in existing self-report questionnaires to tease out anxiety from autistic experiences would influence the way autistic adults self-report their social anxiety and obsessive-compulsive disorder (OCD) symptoms, and if so in what ways. We also wanted to know whether providing these item clarifications would affect the ratings of nonautistic individuals with varying rates of ATs to the same extent. What did the researchers do? We initially consulted two autistic adults and two clinicians with experience working with autistic adults and co-occurring mental health difficulties. We selected two measures: the Social Anxiety Questionnaire (SAQ) for social anxiety symptoms and the Padua Inventory for OCD symptoms. The consultants identified social anxiety and OCD items that could be interpreted or experienced differently by autistic people and proposed ways to clarify them to make their meaning clearer. Next, 50 autistic people and 185 nonautistic university students participated in our online study. The nonautistic participants were grouped into those with higher or lower ATs. Participants completed the original social anxiety and OCD questionnaires first, followed by the clarified versions of the two questionnaires. What were the results of the study? For social anxiety, we only found small differences in ratings when participants used measures with or without clarifications. This was true in both autistic and nonautistic participants. For OCD symptoms, autistic people's OCD ratings were significantly lower for many items after we provided clarifications, especially for items describing repetitive behaviors, "obsessional" thoughts, and contamination fears. This finding suggests that in the original questionnaire, autistic people may have also been rating their autism-related experiences, not just the OCD experiences or symptoms the questionnaire was trying to measure. We found similar differences between the original and clarified item ratings in nonautistic participants with higher and lower ATs. However, the differences were more common and pronounced with the autistic participants. What do these findings add to what was already known? These findings suggest that original self-report measures of anxiety may need to be clarified so that autistic adults can better capture and rate their anxiety, rather than their autism-related experiences. What are potential weaknesses in the study? We used only two anxiety questionnaires, so these findings may or may not be applicable to other OCD or social anxiety questionnaires available. Also, the clarifications we provided may not be representative of all autistic people's experiences, and it is possible that there are other and better ways to clarify the items. We also conducted many item comparisons in this study, so there is a possibility that some findings were due to chance. How will these findings help autistic adults now or in the future? Our findings can help improve clinical interviews and use of anxiety questionnaires by making them more accurate. They can also help clinicians appreciate the importance of asking clarifying questions to ensure they better capture autistic adults' anxiety experiences.
