Association of Positive and Negative Parenting Behavior with Childhood ADHD: Interactions with Offspring Monoamine Oxidase A (MAO-A) Genotype

Relatively little is known about the potential interplay between genetic and environmental influences on attention-deficit/hyperactivity disorder (ADHD), including gene-environment interaction (G×E). There is evidence that parenting behavior interacts with offspring genotype in the development of externalizing problems, but studies have largely focused on explicit maltreatment rather than differentiated measures of parenting behavior, including positive and negative parenting. We tested the interactive effects of the 30-base pair variable number tandem repeat (VNTR) polymorphism of the monoamine oxidase A gene (MAO-A) with positive and negative parenting behavior on parent- and teacher ratings of inattention and hyperactivity symptoms among 150 6–9 year-old boys with and without ADHD. Negative parenting predicted parent and teacher ratings of inattention symptoms, but only among boys with high-activity MAO-A genotype. MAO-A genotype did not moderate the association of positive parenting and parent- and teacher ratings of ADHD. We discuss the potential role of interactive exchanges between parenting behavior and child genotype in the development and persistence of ADHD and related behavior problems.     

The Effects of Childhood ADHD Symptoms on Early-onset Substance Use: A Swedish Twin Study

Research has documented that children and adolescents with attention-deficit/hyperactivity disorder (ADHD) are at increased risk of substance use problems. Few studies, however, have focused on early-onset substance use. This study therefore investigated how the two symptom dimensions of ADHD (hyperactivity/impulsivity and inattention) are associated with early-onset substance use, the role of persistent ADHD for the association, and to what extent the association is influenced by genetic and environmental factors. Twins (1,480 pairs) in the Swedish Twin Study of Child and Adolescent Development were followed from childhood to adolescence. ADHD symptoms were measured at age 8–9 and age 13–14 via parent-report, whereas substance use was assessed at age 13–14 via self-report. Results revealed that hyperactive/impulsive symptoms predicted early-onset “sometimes” tobacco use (adjusted odds ratios, 1.12, for one symptom count), controlling for inattentive symptoms and conduct problem behaviors. There is no independent effect of inattentive symptoms on early-onset substance use. Children with persistent hyperactivity/impulsivity (defined as scoring above the 75th percentile at both time points) had a pronounced risk of both early-onset tobacco and alcohol use (adjusted odds ratios from 1.86 to 3.35, compared to the reference group). The associations between hyperactivity/impulsivity and early-onset substance use were primarily influenced by genetic factors. Our results indicated that hyperactivity/impulsivity, but not inattention, is an important early predictor for early-onset substance use, and a shared genetic susceptibility is suggested to explain this association.     

Stress Overload: A New Approach to the Assessment of Stress

The link between stress and health has not received strong empirical support, possibly due to problems in the stress measures used. Here, the first wholly empirical development of a new “Stress Overload Scale” is described. A pool of 150 items was formed to reflect “overload”, a common denominator in stress theories. Then, the results of five sequenced studies, conducted in heterogeneous community samples, were used to pare the item pool. Exploratory (n = 431) and confirmatory (n = 433) analyses revealed two factors (Event Load and Personal Vulnerability) corresponding to theoretical constructs; only the best factor markers were submitted to further construct validity (n = 310) and reliability tests (n = 342). The 24 strongest items were selected for the SOS, which demonstrated criterion validity in predicting who (n = 285) would become sick following a common stressor. The SOS is (1) psychometrically strong, especially in its validity relative to popular measures; (2) appropriate to community research, due to its brevity and fit to a broad demographic spectrum; (3) unique in its ability to cross‐section individuals into risk categories. It should prove useful to community psychologists in determining etiology, diagnosing risk for pathology, and evaluating the efficacy of interventions.     

Predictors of Boys’ ADHD Symptoms from Early to Middle Childhood: The Role of Father–Child and Mother–Child Interactions

This prospective 3 year longitudinal study investigated preschool paternal and maternal parenting predictors of Attention-Deficit/Hyperactivity Disorder(ADHD) in a community sample of 93 school-age boys. Participants were recruited on the basis of inattention-hyperactivity at age 4 and fathers and mothers were observed interacting with their sons. Teachers, fathers, and mothers reported children's ADHD symptoms and impairment. Results from dimensional analysis showed that less observed paternal sensitivity and maternal positive regard predicted higher levels of inattentiveness in middle childhood, and that intrusive paternal behavior was predictive of hyperactive-impulsive behavior at school. In categorical analysis, less maternal warmth and sensitivity were predictive of later ADHD. These predictions held after statistical adjustment for the effects of preschool ADHD behaviors and conduct problems. At follow-up, parents of boys with ADHD reported more negative child-parent relationship perceptions than comparison parents. Findings highlight the importance of examining responsive parenting behaviors of both fathers and mothers in relation to multi-informant ratings of ADHD symptoms.     

Improving Working Memory in Children with Attention-Deficit/Hyperactivity Disorder: The Separate and Combined Effects of Incentives and Stimulant Medication

Working memory (WM) is considered a core deficit in Attention-Deficit/ Hyperactivity Disorder (ADHD), with numerous studies demonstrating impaired WM among children with ADHD. We tested the degree to which WM in children with ADHD was improved by performance-based incentives, an analog of behavioral intervention. In two studies, WM performance was assessed using a visuo-spatial n-back task. Study 1 compared children (ages 9-12?years) with ADHD-Combined type (n?=?24) to a group of typically developing (TD) children (n?=?32). Study 1 replicated WM deficits among children with ADHD. Incentives improved WM, particularly among children with ADHD. The provision of incentives reduced the ADHD-control group difference by approximately half but did not normalize WM. Study 2 examined the separate and combined effects of incentives and stimulant medication among 17 children with ADHD-Combined type. Both incentives and a moderate dose of long-acting methylphenidate (MPH; ~0.3?mg/kg t.i.d. equivalent) robustly improved WM relative to the no-incentive, placebo condition. The combination of incentives and medication improved WM significantly more than either incentives or MPH alone. These studies indicate that contingencies markedly improve WM among children with ADHD-Combined type, with effect sizes comparable to a moderate dose of stimulant medication. More broadly, this work calls attention to the role of motivation in studying cognitive deficits in ADHD and in testing multifactorial models of ADHD.     

Perfectionism: The good,the bad,and the creative

The influence of adaptive and maladaptive perfectionism on creativity was examined. Initially, six measures of creativity were administered, including creative self-perceptions, behavior, and performance measures. Adaptive perfectionism was weakly positively related to creativity, whereas maladaptive perfectionism was unrelated to creativity across five of the six measures. A follow-up study assessed whether initial findings could be generalized to an everyday problem-solving task. Results indicated that adaptive perfectionism was related to higher quality but not originality of solutions. Further, a curvilinear relationship in the shape of an inverted “U” occurred between adaptive perfectionism and four of eight creativity measures. Overall, adaptive perfectionism was consistently, albeit weakly, related to creativity across various types of measures, whereas maladaptive perfectionism was not related to creativity.     

Hemispheric differences in the effects of context on vowel perception

Listeners perceive speech sounds relative to context. Contextual influences might differ over hemispheres if different types of auditory processing are lateralized. Hemispheric differences in contextual influences on vowel perception were investigated by presenting speech targets and both speech and non-speech contexts to listeners’ right or left ears (contexts and targets either to the same or to opposite ears). Listeners performed a discrimination task. Vowel perception was influenced by acoustic properties of the context signals. The strength of this influence depended on laterality of target presentation, and on the speech/non-speech status of the context signal. We conclude that contrastive contextual influences on vowel perception are stronger when targets are processed predominately by the right hemisphere. In the left hemisphere, contrastive effects are smaller and largely restricted to speech contexts.     

Human sensitivity to the magnitude and probability of a continuous causal relation in a video game

Continuous causation, in which incremental changes in one variable cause incremental changes in another, has received little attention in the causal judgment literature. A video game was adapted for the study of continuous causality in order to examine the novel cues to causality that are present in these paradigms. The spatial proximity of an object to an "enemy detector" produced auditory responses as a function of the object's proximity. Participants' behavior was a function of the range of the effect's auditory sensitivity and the moment-to-moment likelihood of detection. This new paradigm provides a rich platform for examining the cues to causation encountered in the learning of continuous causal relations.