Faculty Bibliography

Recent preclinical data have raised the possibility that prepubertal treatment of attention-deficit/hyperactivity disorder (ADHD) with stimulant medication might increase risk for later depression. The current longitudinal study investigated whether children with ADHD who were treated with stimulant medication displayed heightened levels of adolescent depression. Adolescents diagnosed with ADHD during childhood who had received a minimum of 1 year of treatment with stimulant medication were compared to adolescents with a childhood history of ADHD who were never treated with stimulants and a demographically matched comparison group on self-reports of depressive symptoms and diagnoses of depressive disorders. Both subgroups with childhood ADHD reported significantly higher dimensional ratings of depression and categorical rates of depressive disorders relative to the comparison group (all p<0.05), yet those who were and were not medicated did not differ from one another. Results indicate that, while childhood ADHD increases risk for adolescent depression, stimulant treatment for ADHD neither heightens nor protects against such risk.

PURPOSE OF REVIEW: To summarize research on the emotional and behavioral consequences of childhood maltreatment published between January 2009 and April 2010. RECENT FINDINGS: Many studies published during this time frame replicated prior research studies that have shown that childhood maltreatment is a nonspecific risk factor for a range of different emotional and behavioral problems. Two research groups highlighted the high revictimization rate among abused girls, with more than one in five abused girls found to have subsequent experiences of rape by young adulthood. The association between physical and sexual abuse and subsequent perpetration of violence toward self and other was also demonstrated, with one study noting the particular vulnerability of sexually abused boys to these negative outcomes. In this study, sexually abused boys had a 15-fold increased risk of making a suicide attempt, and a 45-fold increased risk of perpetrating domestic violence. A three-generation longitudinal study of the intergenerational transmission of abuse is also highlighted in the review, together with emerging findings on genetic and environmental risk and protective factors associated with variability in child outcomes. SUMMARY: Maltreated children are at-risk for a host of negative outcomes. Although marked gains have been made in treating trauma-related psychopathology, these recent studies highlight the need to examine long-term outcomes of youths who have received state-of-the-art evidence-based interventions, and determine if there is a need for more comprehensive and sustained intervention approaches

In uncertain situations such as descending challenging slopes, social signals from caregivers can provide infants with important information for guiding action. Previous work showed that 18-month-old walking infants use social information selectively, only when risk of falling is uncertain. Experiment 1 was designed to alter infants' region of uncertainty for walking down slopes. Slippery Teflon-soled shoes drastically impaired 18-month-olds' ability to walk down slopes compared with walking barefoot or in standard crepe-soled shoes, shifting the region of uncertainty to a shallower range of slopes. In Experiment 2, infants wore Teflon-soled shoes while walking down slopes as their mothers encouraged and discouraged them from walking. Infants relied on social information on shallow slopes, even at 0 degrees , where the probability of walking successfully was uncertain in the Teflon-soled shoes. Findings indicate that infants' use of social information is dynamically attuned to situational factors and the state of their current abilities.

PURPOSE: To examine the associations between the size and quality of African-American adolescents' social networks and their mental health service use, and to examine whether these social network characteristics moderate the association between need for services because of emotional or behavioral difficulties and use of services. METHOD: Participants were a community sample of African-American adolescents (N = 465; 46.2% female; mean age, 14.78) initially recruited in 1st grade for participation in an evaluation of two preventive intervention trials. Social network influences and adolescents' mental health service use in schools and community were accessed. RESULTS: A significant positive association between adolescents' perception that their social network was helpful and their use of school mental health services was identified. The significant associations between need for services for anxiety, depression, or behavior problems, and school and outpatient service use were moderated by size of the social network. Specifically, among youth in need of services for anxiety or depression, school-based service use was higher for those with larger social networks. CONCLUSIONS: Implications for enhancing access to formal mental health services include further examination of key social network influences that potentially serve as facilitators or barriers to formal help-seeking. The findings also suggest that it might be important to integrate social network members into interventions to address the mental health needs of adolescents.

BACKGROUND: Noise is typically conceived of as being detrimental for cognitive performance; however, a recent computational model based on the concepts of stochastic resonance and dopamine related internal noise postulates that a moderate amount of auditive noise benefit individuals in hypodopaminergic states. On the basis of this model we predicted that inattentive children would be enhanced by adding background white noise while attentive children's performance would deteriorate. METHODS: Fifty-one secondary school pupils carried out an episodic verbal free recall test in two noise conditions. In the high noise condition, verb-noun sentences were presented during auditory background noise (white noise, 78 dB), and in the low noise condition sentences were presented without noise. RESULTS: Exposure to background noise improved performance for inattentive children and worsened performance for attentive children and eliminated episodic memory differences between attentive and inattentive school children. CONCLUSIONS: Consistent with the model, our data show that cognitive performance can be moderated by external background white noise stimulation in a non-clinical group of inattentive participants. This finding needs replicating in a larger sample using more noise levels but if replicated has great practical applications by offering a non-invasive way to improve school results in children with attentional problems

BACKGROUND: In an attempt to model some behavioral aspects of Attention Deficit/Hyperactivity Disorder (ADHD), we examined whether an existing genetic animal model of ADHD is valid for investigating not only locomotor hyperactivity, but also more complex motor coordination problems displayed by the majority of children with ADHD. METHODS: We subjected young adolescent Spontaneously Hypertensive Rats (SHRs), the most commonly used genetic animal model of ADHD, to a battery of tests for motor activity, gross motor coordination, and skilled reaching. Wistar (WIS) rats were used as controls. RESULTS: Similar to children with ADHD, young adolescent SHRs displayed locomotor hyperactivity in a familiar, but not in a novel environment. They also had lower performance scores in a complex skilled reaching task when compared to WIS rats, especially in the most sensitive measure of skilled performance (i.e., single attempt success). In contrast, their gross motor performance on a Rota-Rod test was similar to that of WIS rats. CONCLUSION: The results support the notion that the SHR strain is a useful animal model system to investigate potential molecular mechanisms underlying fine motor skill problems in children with ADHD

The hippocampus is a part of the limbic system and is important for the formation of associative memories, such as acquiring information about the context (e.g., the place where an experience occurred) during emotional learning (e.g., fear conditioning). Here, we assess whether the hippocampus is responsible for pups' newly emerging context learning. In all experiments, postnatal day (PN) 21 and PN24 rat pups received 10 pairings of odor-0.5 mA shock or control unpaired odor-shock, odor only, or shock only. Some pups were used for context, cue or odor avoidance tests, while the remaining pups were used for c-Fos immunohistochemistry to assess hippocampal activity during acquisition. Our results show that cue and odor avoidance learning were similar at both ages, while contextual fear learning and learning-associated hippocampal (CA1, CA3, and dentate gyrus) activity (c-Fos) only occurred in PN24 paired pups. To assess a causal relationship between the hippocampus and context conditioning, we infused muscimol into the hippocampus, which blocked acquisition of context fear learning in the PN24 pups. Muscimol or vehicle infusions did not affect cue learning or aversion to the odor at PN21 or PN24. The results suggest that the newly emerging contextual learning exhibited by PN24 pups is supported by the hippocampus

OBJECTIVE: Schizophrenia is a neurodevelopmental disorder associated with abnormalities of brain structure and white matter, although little is known about when these abnormalities arise. This study was conducted to identify structural brain abnormalities in the prenatal and neonatal periods associated with genetic risk for schizophrenia. METHOD: Prenatal ultrasound scans and neonatal structural magnetic resonance imaging (MRI) and diffusion tensor imaging were prospectively obtained in the offspring of mothers with schizophrenia or schizoaffective disorder (N=26) and matched comparison mothers without psychiatric illness (N=26). Comparisons were made for prenatal lateral ventricle width and head circumference, for neonatal intracranial, CSF, gray matter, white matter, and lateral ventricle volumes, and for neonatal diffusion properties of the genu and splenium of the corpus callosum and corticospinal tracts. RESULTS: Relative to the matched comparison subjects, the offspring of mothers with schizophrenia did not differ in prenatal lateral ventricle width or head circumference. Overall, the high-risk neonates had nonsignificantly larger intracranial, CSF, and lateral ventricle volumes. Subgroup analysis revealed that male high-risk infants had significantly larger intracranial, CSF, total gray matter, and lateral ventricle volumes; the female high-risk neonates were similar to the female comparison subjects. There were no group differences in white matter diffusion tensor properties. CONCLUSIONS: Male neonates at genetic risk for schizophrenia had several larger than normal brain volumes, while females did not. To the authors' knowledge, this study provides the first evidence, in the context of its limitations, that early neonatal brain development may be abnormal in males at genetic risk for schizophrenia.

OBJECTIVE: Deficits in cognitive flexibility and response inhibition have been linked to perturbations in cortico-striatal-thalamic circuitry in adult obsessive-compulsive disorder (OCD). Although similar cognitive deficits have been identified in pediatric OCD, few neuroimaging studies have been conducted to examine its neural correlates in the developing brain. In this study, we tested hypotheses regarding group differences in the behavioral and neural correlates of cognitive flexibility in a pediatric OCD and a healthy comparison (HC) sample. METHOD: In this functional magnetic resonance imaging (fMRI) study, a pediatric sample of 10- to 17-year-old subjects, 15 with OCD and 20 HC, completed a set-shifting task. The task, requiring an extradimensional shift to identify a target, examines cognitive flexibility. Within each block, the dimension (color or shape) that identified the target either alternated (i.e., mixed) or remained unchanged (i.e., repeated). RESULTS: Compared with the HC group, the OCD group tended to be slower to respond to trials within mixed blocks. Compared with the HC group, the OCD group exhibited less left inferior frontal gyrus/BA47 activation in the set-shifting contrast (i.e., HC > OCD, mixed versus repeated); only the HC group exhibited significant activation in this region. The correlation between set shifting-induced right caudate activation and shift cost (i.e., reaction time differential in response to mixed versus repeated trials) was significantly different between HC and OCD groups, in that we found a positive correlation in HC and a negative correlation in OCD. CONCLUSIONS: In pediatric OCD, less fronto-striatal activation may explain previously identified deficits in shifting cognitive sets.