Exploring the occurrences of, and temporal relationships between, the negative life events, positive parenting, and externalizing and internalizing symptoms in Norwegian adolescents with ADHD: Comparisons with general population and a matched control group.

Background: Research shows that, compared to their peers, adolescents with hyperkinetic disorder (ADHD) experience more negative life events (NLE), less positive parenting, and greater externalizing and internalizing symptoms. However, these findings predominantly stem from comparisons with large general population samples, not the demographically matched, smaller, and clinically relevant samples. The first aim of the current thesis was to explore whether such findings remain consistent across these two analytical approaches. Further, conduct and depression symptoms are frequently comorbid with ADHD, and in the general population these symptoms are mutually influencing and influenced by NLE and parenting. The second aim of this thesis was therefore to explore whether ADHD has a unique effect on the interplay between comorbid symptoms and the occurrence of NLE and positive parenting over time. Method: Longitudinal data from 3,512 (self-reported ADHD: 87) Norwegian 8-10th graders recruited as part of the Monitoring Young Lifestyle study (Brunborg et al., 2019) was used. Adolescents were recruited through their middle schools following parental consent and completed questionnaires annually; only data from T1 (2017) and T2 (2018) were used. To address the first aim, the occurrences of NLE, positive parenting, externalizing, and internalizing symptoms were calculated, and associations between these characteristics and ADHD in the full sample were estimated using regression analyses. A control group was then extracted using pair-matching to the ADHD participants on 6 socio-demographic and health covariates. The ADHD- and matched control group were compared on occurrence of NLE, parenting style, and comorbid symptoms using paired samples t-tests. Finally, to address the second aim, path analysis and cross-lagged panel models were used to compare temporal relationships between NLE, parenting style, and comorbid symptoms between the ADHD and the matched control groups. Results: Across comparison methods, adolescents with ADHD reported significantly more NLE in life history, and less positive parenting, greater externalizing, and internalizing symptoms at T1. At T2 differences in NLE and conduct remained for general population comparisons, but no differences remained for matched control comparisons. Cross-lagged panel models showed better fit when all examined associations between NLE, parenting, internalizing, and externalizing symptoms were estimated as unconstrained multi-group models, documenting a set of complex differences in temporal relationships amongst these constructs between ADHD - and matched control group. The differences primarily reflected high instability in parenting and life events among ADHD adolescents, as well as differences concerning the role of NLE life history and T1 parenting in this group. Conclusion: Differences between adolescents with ADHD and their peers seemed exacerbated in the results from comparisons with the larger population sample (vs. a matched control group). Still, findings suggest a real set of challenges faced by the adolescents with ADHD. There was a significant difference in the cross-lagged panels between the ADHD and the matched control group, such that the examined 1-year period in ADHD group was marked by greater parenting and life events instabilities. Adolescents with ADHD may experience unique effects, compared to peers, on the complex temporal relationships between the NLE, positive parenting, and externalizing and internalizing symptoms