Clinically diagnosed preschool children with ADHD showed robust inhibition deficits, whereas preschool children with DBD showed impaired inhibition especially where motivational incentives were prominent. Severity of inhibition impairment in the comorbid group was similar to the ADHD group.

No abstract

In this longitudinal study, we examined the stability of the association between executive functions and externalizing behavior problems, and the developmental change of executive functions in a predominately clinically diagnosed preschool sample (N = 200). Inhibition and working memory performance were assessed three times in 18 months. Across time, poorer inhibition performance in young children was associated with attention deficit hyperactivity disorder (ADHD) and disruptive behavior disorders (DBD), and poorer working memory performance was associated with ADHD. Inhibition and working memory performance increased over time, especially in the early preschool period. The improvement of inhibition performance was more pronounced in the clinically diagnosed children compared to the TD children.

Longitudinal studies have shown that preschool children's diagnosis of Oppositional Defiant Disorder (ODD), Conduct Disorder (CD) and Attention-Deficit/Hyperactivity Disorder (ADHD) are likely to persist into school age. However, limited attention has been paid to instability of diagnosis. The aim of the present study, therefore, was to investigate both stability and change of ODD, CD and ADHD diagnosis in children aged 3.5-5.5 years. For diagnosing these disorders, a semi-structured diagnostic parent interview, i.e., the Kiddie-Disruptive Behavior Disorder Schedule (K-DBDS), was used at the first assessment and at follow-up assessments (9 and 18 months). Five diagnostic stability groups (chronic, partial remission, full remission, new onset, no diagnosis) were compared with regard to impairment and number of symptoms. Participants were referred preschool children with externalizing behavioral problems (N = 193; 83% male) and typically developing (TD) children (N = 58; 71% male). Follow-up assessments allowed to distinguish children belonging to the chronic group of ODD, CD or ADHD from those belonging to one of the remission groups. In addition, there was a substantial number of children with a new onset diagnosis. In conclusion, as a complement to studies showing stability of ODD, CD and ADHD diagnosis into school age, present findings point to changes of diagnosis in the preschool and early school period. Diagnostic reassessments therefore are needed in this age group.

this is clearly below the clinical cut-off. Is a child with such a clinical profile not meaningfully different from a child exhibiting six or more symptoms in all settings? It has long been recognized that this is the case [22]. We argue that this vaguely defined criterion reflects a broader neglected issue of variability in number and contextual (in)stability of symptoms that is so typical in ADHD affected populations. We believe that variation in number and contextual expression of symptoms is a key factor to improve diagnostic and treatment procedures. Below we provide a new perspective on this issue and how to embrace and not erase it in clinical practice and research [9]. We further believe that observational assessment that allows for standardized assessment of cross-contextual variation in child behavior of the child may aid in a more precise measurement of contextual variability of ADHD symptoms in a manner that is clinically feasible and ecologically valid [7]. Observational assessment should be part of the assessment of ADHD for clinical and research purposes in a similar manner as is currently the gold standard for autism spectrum disorder (ASD).In comparison to the DSM-IV, the DSM-5 has slightly toned down the contextual variability of symptoms. In the DSM-IV, the contextual variability of symptoms was clearly emphasized: it is very unusual for an individual to display the same level of dysfunction in all settings or within the same setting at all times (p. 81). In contrast, in the DSM-5 this contextual variability is formulated as 'typically, symptoms vary depending on context within a given setting' (p. 61). However, in both DSM versions, several situations are specifically described that suppress ADHD symptoms in individuals with ADHD, namely: when (1) frequent rewards are given for appropriate behavior (DSM-IV and DSM-5); (2) the person is under very strict control (DSM-IV) or under close supervision (DSM-5); (3) the person is engaged in especially interesting activities 'Several inattentive or hyperactive-impulsive symptoms are present in two or more settings (e.g., at home, school or work; with friends or relatives; in other activities). ' (p. 60,. It is remarkable that the DSM-5 stresses symptoms rather than impairment in relation to different contexts in the diagnostic criteria for Attention-Deficit/Hyperactivity Disorder (ADHD). One would expect that pervasiveness (criterion C) means the presence of impairment of functioning, due to ADHD symptoms, in two or more settings. According to the DSM-5, a diagnosis of ADHD is warranted-when all other criteria are met-if only two out of the minimal six symptoms occur at school, even though