Experienced Autism: Contributions of Childhood Adversity and Internal Distress in Adult Autism Assessments

Adult autism assessments prioritise clinician observations and developmental history, whereas many adults understand autism through lived experience. Within this tension, factors influencing high endorsement of autistic traits remain unclear. We analysed 245 consecutive NHS first adult autism assessments (median age = 33 years, 52% female), including Social Responsiveness Scale-2 (SRS‑2), Generalised Anxiety Disorder-7 (GAD‑7), Patient Health Questionnaire-9 (PHQ‑9) and Adverse Childhood Experiences (ACE) questionnaire. Although internalising symptoms and childhood adversity were common, neither was significantly associated with clinic-diagnosed autism (CA; 56.7%, n = 141). We defined 'experienced autism' (EA) as moderate or above scores on both SRS‑2 domains. Thirty‑five per cent of EA adults (64/181) did not meet clinical diagnostic thresholds. Linear models adjusted for sex closely associated EA with elevated internalising symptoms (GAD‑7 and PHQ‑9) regardless of CA (all p ⩽ .002). Cumulative ACE scores did not distinguish EA/CA groups but were independently associated with female sex (p = .012). Exploratory multinomial analyses suggested that childhood sensory overwhelm and internalising may contribute to convergence of EA and CA. Associations involving childhood maltreatment were less robust and should be considered hypothesis-generating. These findings support a preliminary hypothesis that elevated autism self-reports may sometimes reflect transdiagnostic associations between adversity and internalising symptoms.Lay AbstractMany adults seeking autism assessments score highly on autism questionnaires, but not all receive an autism diagnosis. This can feel invalidating and may leave people without support. During autism assessments at our NHS clinic, previously unassessed adults completed questionnaires about autism, anxiety, low mood and adverse childhood experiences, including abuse, family difficulties and sensory overwhelm. We reviewed 245 assessment reports (average age 35 years, about half women). We found high levels of childhood adversity, previous mental health diagnoses and current anxiety and depression in our clinic. These levels were similar for adults who received a diagnose of autism (57%) and those who did not (43%). High scores on autism questionnaires were common, yet 35% of adults with moderate or higher scores did not receive a diagnosis. Statistical analyses suggested that high autism questionnaire scores were strongly linked to higher anxiety and depression symptoms for both men and women. Women attending the clinic reported more adverse childhood experiences. When we considered current anxiety and depression, childhood adversity and sex together in the same statistical model, adults who scored highly on the autism questionnaire and were diagnosed autistic at the clinic were more likely to report sensory difficulties in childhood. Some exploratory findings suggested that childhood experiences may contribute differently across groups, although these patterns require replication in future research. Overall, our findings suggest that in first-time adult autism assessments, autism questionnaire scores may be influenced by worry, low mood, difficult childhoods and social experiences, as much as by autism. Our findings support closer connections between adult autism clinics and trauma and mental health specialists, both for diagnosis and for support options. As research links difficult childhoods with many adult health conditions, it may be important to consider anxiety, depression and childhood experiences when thinking about possible autism or connections to other conditions.