Adverse childhood experiences in adults completing ADHD and autism diagnostic assessment: associations with diagnostic outcome and psychiatric symptom burden

Abstract

Background Adult ADHD and autism assessment services increasingly receive clinically heterogeneous referrals in which the sequelae of childhood adversity may overlap with neurodevelopmental presentations. The distribution and clinical significance of adverse childhood experiences (ACEs) in this referral population remain insufficiently characterized. Methods This retrospective cross-sectional cohort study analyzed routinely collected clinical data from 389 adults who attended either the ADHD or the autism diagnostic pathway of a regional National Health Service (NHS) Adult ADHD and Autism Service. The analytic sample consisted of 233 adults with a definitive diagnostic outcome at data extraction; 149 were awaiting an outcome, six had an inconclusive outcome, and one underage case was excluded. ACE exposure was measured with the 10-item ACE Questionnaire. Psychiatric symptom burden was assessed with routinely administered screening instruments (PHQ-9, GAD-7, AUDIT, DAST-10, MDQ, HELPS and IPDS). The primary analysis examined the association between ACE score, analyzed as a continuous variable, and diagnostic outcome, with adjustment for age, gender and assessment pathway in binary logistic regression; all other analyses were exploratory. Results Forty-seven participants (20.2%) received a diagnosis of ADHD or autism and 186 (79.8%) did not meet DSM-5 criteria. The mean ACE score was 3.10 (SD = 2.59), and 39.7% of participants reported four or more ACEs, compared with 8.3% in an English national household survey. Participants who were not diagnosed reported higher ACE scores than participants who were diagnosed (3.37 vs. 2.04; Hedges g = 0.52, 95% CI 0.19–0.84, p = 0.002). In the adjusted model, each additional ACE was associated with lower odds of receiving a neurodevelopmental diagnosis (odds ratio 0.85, 95% CI 0.73–0.99, p = 0.040). The proportion diagnosed declined across ACE categories from 35.6% (no adversity) to 6.2% (six or more ACEs). ACE scores correlated positively with depressive symptoms (r = 0.37), anxiety symptoms (r = 0.28) and drug use scores (r = 0.27), but not alcohol use, and were higher among participants screening positive for possible personality disorder, head injury and mood disorder. In an exploratory model additionally adjusting for depressive symptoms and personality disorder screening status, the ACE association attenuated and was no longer statistically significant, indicating that it is not independent of concurrent psychiatric symptom burden. Conclusions ACE exposure in this referral cohort was substantially higher than English population estimates and was associated with diagnostic non-confirmation and with greater psychiatric symptom burden. These findings support consideration of childhood adversity within trauma-informed formulation during adult neurodevelopmental assessment. Prospective studies incorporating direct measures of trauma-related psychopathology are needed to determine whether trauma-related mechanisms contribute to neurodevelopmental-like presentations. The cross-sectional retrospective design precludes causal inference.