Late-emerging ADHD symptoms and their association with psychotic experiences in a general population-based stimulant-naïve adolescent cohort

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) has been associated with an increased risk of subsequent psychotic disorders. However, ADHD symptom trajectories have not been adequately considered, and it remains unclear whether associations with psychotic experiences (PEs) differ across trajectories among adolescents without reported psychostimulant use. AIMS: To examine associations between ADHD symptom trajectories and self-reported PEs in a population-based adolescent cohort without reported ADHD pharmacotherapy use. METHODS: We analysed 2245 participants from the Tokyo Teen Cohort assessed at ages 10, 12, 14, and 16 years. Participants with reported ADHD pharmacotherapy use were excluded, and none reported lifetime cannabis use at age 16. Parent-reported ADHD symptom trajectories were identified using growth mixture modelling. Logistic and multinomial logistic regression analyses examined associations with overall, distressing, and non-distressing PEs at age 16, adjusting for potential confounders at age 10, including baseline PEs. RESULTS: Four trajectories were identified: stable-low (67.6%), partial-persistent (13.2%), late-decreasing (12.3%), and late-emerging (6.9%). Compared with the stable-low trajectory, the late-emerging trajectory was associated with overall PEs (adjusted odds ratio [aOR], 1.93; 95% confidence interval [CI], 1.05-3.55) and distressing PEs (aOR, 2.06; 95% CI, 1.01-4.20). The partial-persistent trajectory was associated with non-distressing PEs (aOR, 2.36; 95% CI, 1.08-5.19). CONCLUSIONS: Associations with PEs differed across ADHD symptom trajectories. Newly emerging or worsening ADHD symptoms during adolescence may warrant assessment of broader psychopathology, including PEs.