Comparatively little information is available from population-based studies on subgroup trajectories of attention-deficit/hyperactivity disorder (ADHD) core symptoms of inattention and hyperactivity-impulsivity (particularly as defined by DSM-IV and ICD-10). Recent report of a subgroup with high and increasing inattention symptoms across development requires replication. To identify the different trajectory subgroups for inattention, hyperactivity-impulsivity and total symptoms of ADHD in children and adolescents aged 7-19 years. Eleven birth cohorts from 2,593 families with children and adolescents who had parent ratings for the outcome measures of inattention, hyperactivity-impulsivity or total symptoms were considered. Data were analysed using an accelerated longitudinal design and growth mixture modelling was applied to detect subgroups. For all three outcome measures, three trajectories with low (78.3-83.3 %), moderate (13.4-18.8 %) and high (2.8-3.2 %) symptom levels were detected. Course within these subgroups was largely comparable across outcome domains. In general, a decrease in symptoms with age was observed in all severity subgroups, although the developmental course was stable for the high subgroups of inattention and total symptoms. About 3 % of children in a community-based sample follow a course with a high level of ADHD symptoms. In this high trajectory group, hyperactivity-impulsivity symptoms decrease with age from 7 to 19 years, whilst inattention and total symptoms are stable. There was no evidence for an increase in symptoms across childhood/adolescence in any of the severity groups.

The TASH program enhances effects of methylphenidate treatment in families who complete the intervention. The discontinuation rate of about 30% and comparison between completing and discontinuing families suggest that the program may be more suitable for families with a higher educational level and fewer additional stresses.

CBCL: Child Behaviour Checklist; CII: Coder Impressions Inventory; DASS: Depression anxiety Stress Scale; HSQ: Home-situation Questionnaire; LSS: Life Satisfaction Scale; OBDT: observed behaviour during the test; PCL: Problem Checklist; PEP: prevention programme for externalizing problem behaviour; PPC: Parent Problem Checklist; PPS: Parent Practices Scale; PS: Parenting Scale; PSBC: Problem Setting and Behaviour checklist; QJPS: Questionnaire on Judging Parental Strains; SEFS: Self-Efficacy Scale; SSC: Social Support Scale; TRF: Caregiver-Teacher Report Form.

Background Our indicated Prevention program for preschool children with Externalizing Problem behavior (PEP) demonstrated improved parenting and child problem behavior in a randomized controlled efficacy trial and in a study with an effectiveness design. The aim of the present analysis of data from the randomized controlled trial was to identify the mediating processes that account for these positive treatment effects. We hypothesized that a decrease in negative parenting and increases in positive parenting and parental warmth would mediate the relationship between treatment and child improvement. Method Parents of 155 children were randomly assigned to the PEP intervention group (n = 91) or a nontreated control group (n = 64). Parents rated their child's problem behavior and their own parenting practices before and after PEP training. Parental warmth was assessed during standardized play situations. Four mediation models were tested using structural equation modeling. Trial registration number ISRCTN12686222; http://www.controlled-trials.com/isrctn/pf/12686222. Results Changes in child externalizing problem behavior were most strongly mediated by reductions of negative parenting in difficult parenting situations. Increases in positive parenting also served as a mediator. Changes in parental warmth, parents' feeling of self‐efficacy, and parental mental health did not play a mediating role in the association between PEP treatment and child behavior. Conclusions In our program, the most important component was to teach parents how to reduce dysfunctional parenting strategies in conflict situations.

The results support the factorial validity, reliability, and divergent validity of the WFIRS-P.