Faculty Bibliography

Childhood aggression has both biological and environmental underpinnings. However, the manner in which these factors interact to influence various types of aggression remains an important area of study. The current study examined the degree to which biological risk and psychosocial adversity, both alone and in combination, are associated with childhood aggression. Linear regression procedures were used to assess the extent to which biological risk status (low vs. high serotonergic responsivity, as measured by prolactin response to fenfluramine), magnitude of psychosocial risk, and the interaction of these factors predicted parent and teacher ratings of aggression and delinquency. After accounting for the independent contribution of biological and psychosocial risk, the interaction of biological and psychosocial risk was significantly associated with parent-rated aggression and marginally related to parent-rated delinquency. In contrast, no such interaction was observed for teacher-rated aggression. Findings suggest that individuals at biological risk for aggression may be particularly vulnerable to the impact of psychosocial adversity.

OBJECTIVES: This study examined whether high levels of television viewing are associated with attention problems and hyperactivity in preschool children. METHODS: Parent and teacher ratings of inattention, hyperactivity and impulsivity, objectively measured activity level, and parental estimation of early television exposure were collected for a sample of preschool children. Separate linear regression analyses were conducted with parent and teacher behavioral ratings and objectively assessed activity level as outcome variables. RESULTS: Results indicated that after controlling for demographic factors (i.e., age, sex, and SES), television exposure accounted for a significant proportion of the variance in teacher ratings of inattentive/hyperactive behaviors, as well as objectively measured activity level. CONCLUSIONS: These findings partially replicate those from a recent, highly publicized study indicating a correlation between television exposure and attention-deficit/hyperactivity disorder (ADHD)-associated behaviors. However, it remains unclear as to whether elevated levels of television viewing are the cause or result of ADHD symptoms.

The psychometric properties of the Alabama Parenting Questionnaire-Preschool Revision (APQ-PR) were explored in a sample of hyperactive-inattentive preschool children (N = 47) and nonimpaired controls (N = 113). A subset of parents completed the questionnaire on 2 occasions, approximately 1 year apart. Factor analysis revealed a 3-factor solution, accounting for 32.28% of the variance. The resultant Positive Parenting, Negative/Inconsistent Parenting, and Punitive Parenting factors demonstrated good internal consistency and temporal stability. At baseline, parents of hyperactive-inattentive and control children did not differ on any APQ-PR subscale. However, over time parents of controls increased their use of positive parenting techniques, whereas the use of positive parenting practices decreased over time in the hyperactive-inattentive group.

This study tested the convergence of behavioral inhibition measures across emotional and non-emotional versions of the same go/no-go task in 85 college students. The two tasks differed only in the stimuli used for trial cues (i.e., circles versus facial expressions). Moderate correlations (r=.51-.56) between commission errors across the emotional and non-emotional tasks support the construct validity of behavioral inhibition. Further, parametric manipulation of preceding context had comparable effects on performance on the two tasks. Responses were slower and more variable, commission errors were more numerous, and perceptual sensitivity was lower on the emotional than the non-emotional task. A bias for happy faces on the emotional task resulted in faster responses and more commission errors for happy than sad faces despite marginally greater sensitivity for the latter. These results suggest that the basic neuropsychological constructs of the original go/no-go task were preserved in the emotional adaptation.

OBJECTIVE: This longitudinal study examined whether responsiveness of the neurotransmitter serotonin (5-HT) in childhood predicts adolescent aggression. METHOD: Boys (N = 33) with disruptive behavior disorders who received assessments of central 5-HT function via the prolactin response to fenfluramine between 1990 and 1994 when they were 7 to 11 years old were re-evaluated clinically on average 6.7 years later. RESULTS: After accounting for baseline aggression, early 5-HT function accounted for a significant proportion of variance in adolescent aggression. This prospective relationship of childhood 5-HT function with adolescent aggression (r = -0.71) and antisocial behavior (r = -0.59) was found primarily in adolescents who were aggressive during childhood. Irrespective of childhood aggression, no child with high 5-HT function was particularly aggressive at follow-up. CONCLUSIONS: Low childhood 5-HT function appears important, but not sufficient, for the emergence of adolescent aggression. However, early high 5-HT function may protect against adolescent violence and aggression.

Premorbid intellectual function estimation is a crucial part of patient evaluation following a traumatic brain injury (TBI), especially in individuals with ADHD who are at higher risk for TBI compared to their non-ADHD peers. This study investigates the value of using regression-based estimates of intelligence for concurrently predicting measured intelligence in a sample of older adolescents with and without a childhood history of ADHD. Correlations between measured and estimated intelligence are highly significant in the full sample and in the individual groups. Adding reading performance to the regression equation increases the accounted-for variance in both groups. Results indicate that regression equations based on demographic characteristics constitute a valid method for estimating premorbid functioning in adolescents with ADHD and that they can play an essential role in the assessment of individuals with ADHD who sustain TBI, especially when measures of word reading are used to augment demographic estimates.

BACKGROUND: Studies of school-aged children, adolescents, and adults with Attention Deficit/Hyperactivity Disorder (ADHD) have variably shown ADHD-related impairment in both inhibitory control and sustained attention. However, few studies have examined ADHD-associated patterns of performance on these tasks among younger children (below age 7 years). METHODS: A combined continuous performance test and go/no-go task (CPT/GNG) and the Day-Night Stroop Task (DNST) were administered to an ethnically diverse sample of 3.44- to 6.95-year-old children rated by parents and teachers as being either high risk or low risk for ADHD. All children performed the DNST (N = 71) and a subset of the sample (N = 44) performed the CPT/GNG. Analyses assessed task validity as well as the effects of age and risk status. RESULTS: Significant main effects for age and risk status were found on all tasks. In addition, age x condition interactions were found for the CPT and DNST, which suggest that the tasks were sensitive to age-related changes in sustained attention and inhibitory control respectively. No significant risk status x condition interactions were found, suggesting that young children at risk for ADHD do not exhibit specific deficits in either inhibitory control or sustained attention. The most consistent effect related to risk status across tasks was the greater number of errors and longer and more variable reaction times on the part of children at risk for ADHD irrespective of condition. CONCLUSIONS: ADHD-associated decrements in performance on these tasks appear to be attributable either to generalized behavioral dysregulation or poor state regulation rather than to deficient inhibitory control.

The authors examined the neuropsychological status of 22 preschoolers at risk for attention-deficit/hyperactivity disorder (ADHD) and 50 matched control children, using measures of nonverbal working memory, perceptual and motor inhibition, and memory for relative time. All tasks included paired control conditions, which allowed for the isolation of discrete executive function constructs. Group differences were evident on several measures of neuropsychological functioning; however, after accounting for nonexecutive abilities, no deficits could be attributed to specific functions targeted by the tasks. Performance on executive measures was not related to objective indices of activity level or ratings of ADHD symptoms. Yet, the fact that at-risk preschoolers were highly symptomatic casts doubt on whether executive function deficits and/or frontostriatal networks contribute etiologically to early behavioral manifestations of ADHD.

The authors examined inhibitory control processes in 8 adolescents diagnosed with attention-deficit/ hyperactivity disorder (ADHD) during childhood and in 8 adolescent control participants using functional MRI with the Stimulus and Response Conflict Tasks (K. W. Nassauer & J. M. Halperin, 2003). No group differences in performance were evident on measures of interference control and/or response competition created by location and direction stimuli. However, the ADHD group demonstrated significantly greater activation of the left ventrolateral prefrontal cortex during interference control as well as greater activation of the left anterior cingulate cortex, right ventrolateral prefrontal cortex, and left basal ganglia during the dual task of interference control and response competition. The magnitude of the prefrontal and basal ganglia activation was positively correlated with severity of ADHD. Response competition alone did not yield group differences in activation.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) occurs in as many as 4 percent of adults yet it is often not recognized in clinical settings because the presenting symptoms may resemble those seen in other disorders or because symptoms may be masked by commonly comorbid conditions such as anxiety and depression. OBJECTIVE: The purpose of this study was to examine the diagnostic utility of instruments commonly used in the assessment of adults presenting with symptoms of ADHD. METHODS: We reviewed several widely used self-report and laboratory measures and empirically examined the utility of the Brown Attention-Deficit Disorder Scale for Adults (Brown ADD Scale) and the Conners Continuous Performance Test (CPT) in differentially identifying adults with ADHD and those with other Axis I disorders. RESULTS: Ninety-three adults who self-referred to the ADHD program for adults at a university medical center participated in the study. Of these, 44 had ADHD combined subtype (ADHD-CB), and 26 had ADHD, predominantly inattentive subtype (ADHD-IA). Thirty-three non-ADHD adults diagnosed with Axis I mood or anxiety disorders comprised an "Other Psychiatric" group. Rates of comorbid disorders, including substance abuse, in the ADHD groups were typical of those reported in the adult ADHD literature. Data on the Brown ADD Scale and on the CPT were available for subsets of 61 and 46 participants, respectively. Analyses showed that the ADHD-CB, ADHD-IA, and Other Psychiatric groups all received mean scores in the clinical range on the Brown ADD Scale, with a trend toward even higher elevations in the two ADHD groups. Among 12 CPT variables assessed for the three groups, the mean scores on only two variables for the ADHD-IA group were clinically elevated. Neither the Brown ADD Scale nor CPT scores evinced sufficient sensitivity and specificity to qualify them to assist in differential diagnosis of ADHD vis-a-vis other, predominantly internalizing, psychiatric disorders. CONCLUSION: The results indicate a need for closer examination of executive and adaptive functioning in adults with ADHD compared with those with internalizing disorders in order to identify features that could assist in differential diagnosis.