Objective: To evaluate the predictive power of executive functions, in particular, response inhibition, in relation to alcohol-related problems and illicit drug use in adolescence. Method: A total of ...498 children from 275 families from a longitudinal high-risk study completed executive function measures in early and late adolescence and lifetime drinking and drug-related ratings at multiple time points including late adolescence (ages 15-17). Multi-informant measures of attention-deficit/hyperactivity disorder and conduct disorder were obtained in early childhood (ages 3-5), middle childhood, and adolescence. Results: In multilevel models, poor response inhibition predicted aggregate alcohol-related problems, the number of illicit drugs used, and comorbid alcohol and drug use (but not the number of drug-related problems), independently of IQ, parental alcoholism and antisocial personality disorder, child attention-deficit/hyperactivity disorder and conduct symptoms, or age. Multivariate models explained 8% to 20% of residual variance in outcome scores. The incremental predictive power of response inhibition was modest, explaining about 1% of the variance in most outcomes, but more than 9% of the residual variance in problem outcomes within the highest risk families. Other measured executive functions did not independently predict substance use onset. Conclusion: Models of alcoholism and other drug risks that invoke executive functions may benefit from specifying response inhibition as an incremental component. (Contains 3 tables.)
This article outlines the parallels between major theories of attention deficit hyperactivity disorder (ADHD) and relevant temperament domains, summarizing recent research from our laboratories on ...(a) child temperament and (b) adult personality traits related to ADHD symptoms. These data are convergent in suggesting a role of effortful control and regulation in the core symptoms of ADHD. Negative approach and anger is also associated with ADHD, but this may be due to the overlap of ADHD and antisocial behavior. Positive approach may be involved in an alternate pathway to ADHD. The involvement of effortful control is congruent with experimental findings of executive functioning deficits in children with ADHD. We hypothesize that, whereas regulation problems may occur in most children with ADHD, a subgroup also may be characterized by positive approach problems and another subgroup by negative approach problems. We conclude with a theorized multiple process developmental model outlining alternate pathways to ADHD that warrant empirical investigation to better resolve etiological heterogeneity in ADHD.
The theory that attention-deficit/hyperactivity disorder (ADHD) stems from a deficit in an executive behavioral inhibition process has been little studied in adults, where the validity of ADHD is in ...debate. This study examined, in high-functioning young adults with persistent ADHD and a control group, 2 leading measures of inhibitory control: the antisaccade task and the negative priming task. ADHD adults showed weakened ability to effortfully stop a reflexive or anticipated oculomotor response but had normal ability to automatically suppress irrelevant information. Results suggest that an inhibitory deficit in ADHD is confined to effortful inhibition of motor response, that antisaccade and negative priming tasks index distinct inhibition systems, and that persistence of ADHD symptoms into adulthood is associated with persistence of executive motor inhibition deficits.
Attention-deficit hyperactivity disorder (ADHD) is a heritable disorder, prevalent from childhood through adulthood. Although the noradrenergic (NA) system is thought to mediate a portion of the ...pathophysiology of ADHD, genes in this pathway have not been investigated as frequently as those in the dopaminergic system. Previous association studies of one candidate gene in the NA system, ADRA2A, showed inconsistent results with regard to an MspI polymorphism. In the current study, two nearby single-nucleotide polymorphisms, which define HhaI and DraI restriction fragment length polymorphisms, were also genotyped and were in significant linkage disequilibrium with the MspI RFLP. Transmission disequilibrium tests (TDTs) in a sample of 177 nuclear families showed significant association and linkage of the DraI polymorphism with the ADHD combined subtype (P=0.03), and the quantitative TDT showed association of this polymorphism with the inattentive (P=0.003) and hyperactive-impulsive (P=0.015) symptom dimensions. The haplotype that contained the less common allele of the DraI polymorphism likewise showed a strong relationship with the inattentive (P=0.001) and hyperactive-impulsive (P=0.004) symptom dimensions. This study supports the hypothesis that an allele of the ADRA2A gene is associated and linked with the ADHD combined subtype and suggests that the DraI polymorphism of ADRA2A is linked to a causative polymorphism.
Response disinhibition is one of several processes that may account for disruptive behavior problems. It is associated with both attention deficits/hyperactivity (ADHD-C) and early onset, ...unsocialized conduct disorder (CD-E). Response inhibition is not a unitary construct. It is best understood via a dual process model of regulatory control. Executive inhibition refers to deliberate suppression of immediate motor behavior in the service of a distal goal in working memory, with relatively low anxiety activation. It is instantiated in the same frontal-striatal-thalamic neural loops as executive function and corresponds in temperament theory to effortful control. Motivational or reactive inhibition refers to anxiety-provoked interruption of behavior in the context of unexpected, novel, or punishment-cue indicators. Along with reward-response and hostile/angry response it corresponds to reactivity in temperament theory, and invokes limbic responsivity. With regard to these types of inhibitory control, ADHD-combined type is predominantly associated with dysfunctional executive inhibition. CD-E is predominantly associated with dysfunctions in the motivational inhibition process, with smaller, secondary effects in executive control. However, in both syndromes etiological heterogeneity is notable. For example, recent evidence indicates that executive inhibitory control is familial, but characterizes only a subset of children with ADHD-C. Recent dual-process models for both ADHD-C and CD-E are therefore important; they are noted and integrated. Examination of the correlates of behavioral inhibition in the subgroups with these inhibitory deficits may prove fruitful in clarifying the diverse routes to disruptive psychopathology in children.
The Symbol Digit Modalities Test SDMT; Smith, A. (1982).
Symbol Digit Modalities Test. Los Angeles: Western Psychological Services; Smith, A. (1968). The symbol-digit modalities test: a ...neuropsychologic test of learning and other cerebral disorders. In J. Helmuth (Ed.),
Learning disorders (pp. 83–91). Seattle: Special Child Publications is a substitution task that is the inverse of the Digit Symbol Test Wechsler, D. (1955).
Manual for the Wechsler Adult Intelligence Scale (WAIS). New York: The Psychological Corporation. The familiar task of filling numbers in boxes, and the availability of an oral administration, make this a popular screening instrument for brain impairment. Normative data were previously reported for a variety of clinical groups, but complete information on non-clinical samples across age, education, gender, and socioeconomic status is limited. The present study examines the performance of a community-dwelling control sample across age, education, gender, and income groupings. In a multivariate model, these four variables did not impact test performance. These results support the utilization of the SDMT as a robust screening test for adult neuropsychological impairment.
Hormonal influences on the organization of behavior are apparent to neuroendocrinologists but under-examined in relation to childhood and adolescent mental disorders. A central mystery in the field ...of developmental psychopathology is the preferential male vulnerability to behavior disorders in childhood and female vulnerability to emotional disorders in adolescence. Relative neglect of a hormonal explanation may be due to lack of simple or unifying conceptual paradigms to guide studies. This paper seeks to stimulate research in this area by drawing upon clinical psychology and neuroscience literatures to offer a heuristic paradigm for clinical research. Two syndromes are selected here for illustration: Attention-Deficit/Hyperactivity Disorder (ADHD) and Major Depressive Disorder (MDD), because they have opposite gender risk profiles. Two guiding theories are evaluated. First, prenatal organizational effects of testosterone may modulate striatally-based dopaminergic circuits in such a way as to place boys at greater risk for early developing inattention and disruptive behavioral disorders. Second, activational effects of estradiol at puberty may modulate amygdalar and other circuitry, with particular effects on serotonergic pathways, in such a way as to place girls at greater risk for internalizing and mood disorders. Hypotheses from these theories are evaluated based on the current available literature, and limitations of, and future directions for, this literature are discussed.
Background: Behavioral genetic studies provide strong evidence that attention‐deficit/hyperactivity disorder (ADHD) has a substantial genetic component. Yet, due to the complexity of the ADHD ...phenotype, questions remain as to the specific genes that contribute to this condition as well as the pathways from genes to behavior. Endophenotypes, or phenotypes that are more closely linked to the neurobiological substrate of a disorder, offer the potential to address these two issues simultaneously (Freedman, Adler, & Leonard, 1999). Thus far, potential endophenotypes for ADHD have not been systematically studied.
Method: The current paper reviews evidence supporting the use of deficits on neurocognitive measures of executive functions for this purpose.
Results: Such deficits are a correlate of ADHD and show preliminary evidence of heritability and association with relevant candidate genes. Nonetheless, studies that have assessed the familial and genetic overlap of neurocognitive impairments with ADHD have yielded inconsistent results.
Conclusions: In order for executive function deficits to be used as an endophenotype for ADHD, we recommend greater attention to the neurocognitive heterogeneity of this disorder and to the precision of measurement of the neuropsychological tests employed. We also discuss empirical strategies that may be necessary to allow such research to progress prior to full resolution of the pathophysiological basis of ADHD.
335 children of alcoholic and nonalcoholic fathers were examined to study the relation between childhood behavior trajectories and adolescent substance abuse. Findings suggested that children with ...both aggression and inattention/hyperactivity were at an increased risk of substance abuse when compared to children with only inattention/hyperactivity and also predicted an earlier onset of drug use in adolescent, independent of aggression.
Because of the centrality of peer relationship difficulties for children with attention-deficit hyperactivity disorder (ADHD), we investigated behavioral (overt and covert antisocial activity), ...internalizing (self-reports and observed social isolation), and familial (authoritative, authoritarian, and permissive parenting beliefs) predictors of peer sociometric nominations among previously unfamiliar, ethnically diverse ADHD (N = 73) and comparison (N = 60) boys, aged 6-12 years. Authoritative maternal parenting beliefs and negatively weighted social isolation explained significant variance in positive peer regard; aggression, covert behavior, and authoritative parenting beliefs were the independent predictors of both negative peer status and peer social preference. We extended such predictions with statistical control of (1) child cognitive variables, (2) maternal psychopathology, and (3) ADHD versus comparison status. It is important to note that aggression predicted peer rejection more strongly for comparison than for ADHD boys, but authoritative parenting beliefs were stronger predictors in ADHD than in comparison youth. We discuss family-peer linkages regarding peer competence.
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