The aim of the present study was to investigate whether attachment insecurity, focusing on disorganized attachment, and the executive function (EF) component of inhibition, assessed at age 5, were longitudinally related to general externalizing problem behaviors as well as to specific symptoms of ADHD and Autism spectrum disorder (ASD), and callous-unemotional (CU) traits. General externalizing problem behaviors were also measured at age 5 to allow for a developmental analysis. Outcome variables were rated by parents and teachers. The sample consisted of 65 children with an oversampling of children with high levels of externalizing behaviors. Attachment was evaluated using a story stem attachment doll play procedure. Inhibition was measured using four different tasks. The results showed that both disorganized attachment and poor inhibition were longitudinally related to all outcome variables. Controlling for initial level of externalizing problem behavior, poor inhibition predicted ADHD symptoms and externalizing problem behaviors, independent of disorganized attachment, whereas for ASD symptoms no predictive relations remained. Disorganized attachment independently predicted CU traits.

The present study, including children at risk for developing Attention Deficit Hyperactivity Disorder (ADHD), examined the idea that complex executive functions (EFs) build upon more simple ones. This notion was applied in the study of longitudinal interrelations between core EF components - simple and complex inhibition, selective attention, and working memory (WM) - at age 5 and 6 as well as their predictive relations to ADHD symptoms at age 7. The results showed that simple inhibition and selective attention at age 5 independently predicted complex inhibition and WM at age 6. In addition, EFs primarily predicted symptoms of inattention rather than hyperactivity/impulsivity even at this young age. Finally, age 6 complex inhibition was shown to act as a mediator in the relations between simple inhibition and selective attention at age 5 and symptoms of inattention at age 7. These findings provide novel longitudinal support for the theory that fundamental EF components show a progression with age toward more complex executive control (see Garon et al. Psychological Bulletin 134(1):31-60 2008). Further, complex inhibition, implicating both inhibition and WM, seems to be a particularly strong correlate of ADHD symptoms in young children and should as such be the focus of future studies examining the relation between cognitive function and ADHD symptoms from a developmental perspective.

This study examined the contributions of several important domains of functioning to ADHD symptoms and conduct problems. Specifically, we investigated if cognitive inhibition, emotion regulation, emotionality and disorganized attachment made independent and specific contributions to these externalizing behavior problems from a multiple pathways perspective.The study included laboratory measures of cognitive inhibition and disorganized attachment in 184 typically developing children (M age = 6 years, 10 months, SD = 1.7). Parental ratings provided measures of emotion regulation, emotionality, and externalizing behavior problems.Results revealed that cognitive inhibition, regulation of positive emotion, and positive emotionality were independently and specifically related to ADHD symptoms. Disorganized attachment and negative emotionality formed independent and specific relations to conduct problems. Our findings support the multiple pathways perspective on ADHD, with poor regulation of positive emotion and high positive emotionality making distinct contributions to ADHD symptoms. More specifically, our results support the proposal of a temperamentally based pathway to ADHD symptoms. The findings also indicate that disorganized attachment and negative emotionality constitute pathways specific to conduct problems rather than to ADHD symptoms.Keywords: ADHD, conduct problems, cognitive inhibition, emotion regulation, emotionality, disorganized attachment. HETEROGENEITY OF EXTERNALIZING BEHAVIOR PROBLEMS 1The Heterogeneity of ADHD Symptoms and Conduct Problems:Cognitive Inhibition, Emotion Regulation, Emotionality and Disorganized Attachment Externalizing behavior problems, such as Attention-Deficit/Hyperactivity Disorder (ADHD) and conduct problems, are increasingly suggested to be etiologically heterogeneous (Dodge & Pettit, 2003;Nigg, Willcutt, Doyle, & Sonuga-Barke, 2005;Sonuga-Barke, 2005).Indeed, the development of conduct problems has long been related to impairments in a multitude of factors, such as emotion regulation, emotionality, cognitive inhibition, and attachment (Dodge & Pettit, 2003). Similarly, current theoretical models of ADHD suggest multiple pathways to the disorder (Nigg, Goldsmith, & Sachek, 2004;Sonuga-Barke, 2005), and recently deficits in emotion regulation and extreme emotionality (Martel, 2009), as well as insecure attachment have been emphasized (Thorell, Rydell, & Bohlin, 2012; for a discussion see Nigg, 2006). There is a shortage of studies simultaneously investigating factors from multiple domains of functioning in relation to both ADHD symptoms and conduct problems. Moreover, few studies have accounted for the substantial overlap between ADHD symptoms and conduct problems. Addressing these limitations would clarify impairment specificity for respective type of externalizing behavior problems, which in turn would help to improve intervention targets (Moffitt et al., 2011; Sonuga-Bark, 2005).Externalizing behavior problems have been shown to be best understood from a dimensiona...

The objective was to examine the relations between attention deficit hyperactivity disorder (ADHD) symptoms and four working memory (WM) components (short-term memory and central executive in verbal and visuospatial domains) in 284 6-16-year-old children from the general population. The results showed that verbal and visuospatial short-term memory and verbal central executive uniquely contributed to inattention symptoms. Age interacted with verbal short-term memory in predicting inattention, with the relation being stronger in older children. These findings support the notion of ADHD as a developmental disorder, with changes in associated neuropsychological deficits across time. The results further indicate ADHD-related deficits in several specific WM components.

The present study investigated whether the Childhood Executive Function Inventory (CHEXI) can discriminate between young children fulfilling the diagnostic criteria for attention-deficit/hyperactivity disorder (ADHD) and normally developing children. Unlike other executive function rating instruments, the CHEXI focuses specifically on inhibitory control and working memory, without including items that overlap with the diagnostic criteria of ADHD. The CHEXI was found to discriminate very well between children fulfilling the criteria for ADHD and normally developing children, also when controlling for the effect of IQ and socioeconomic status (SES). Both sensitivity and specificity of the two CHEXI subscales were shown to be high using either parent or teacher ratings. The highest overall classification rate was found for parent ratings on the inhibition subscale, with sensitivity and specificity reaching 93.3. To summarize, the CHEXI should be considered a promising measure for identifying young children with ADHD, although it is for future research to determine whether the CHEXI can be successfully used to also discriminate between different psychopathological groups.