Faculty Bibliography

Since its inception, experimental psychology has sought to account for individual differences in human performance. Some neuroimaging research, involving complex behavioral paradigms, has suggested that faster-performing individuals show greater neural activity than slower performers. Other research has suggested that faster-performing individuals show less neural activity than slower performers. To examine the neural basis of individual performance differences, we had participants perform a simple speeded-processing task during fMRI scanning. In some prefrontal cortical (PFC) brain regions, faster performers showed less cortical activity than slower performers while in other PFC and parietal regions they showed greater activity. Regional-causality analysis indicated that PFC exerted more influence over other brain regions for slower than for faster individuals. These results suggest that a critical determinant of individual performance differences is the efficiency of interactions between brain regions and that slower individuals may require more prefrontal executive control than faster individuals to perform successfully

The heterodimeric tumor-suppressor complex BRCA1/BARD1 exhibits E3 ubiquitin ligase activity and participates in cell proliferation and chromosome stability control by incompletely defined mechanisms. Here we show that, in both mammalian cells and Xenopus egg extracts, BRCA1/BARD1 is required for mitotic spindle-pole assembly and for accumulation of TPX2, a major spindle organizer and Ran target, on spindle poles. This function is centrosome independent, operates downstream of Ran GTPase, and depends upon BRCA1/BARD1 E3 ubiquitin ligase activity. Xenopus BRCA1/BARD1 forms endogenous complexes with three spindle-pole proteins, TPX2, NuMA, and XRHAMM--a known TPX2 partner--and specifically attenuates XRHAMM function. These observations reveal a previously unrecognized function of BRCA1/BARD1 in mitotic spindle assembly that likely contributes to its role in chromosome stability control and tumor suppression.

BACKGROUND: Controversy concerning the diagnosis of pediatric bipolar disorder (BD) has focused attention on children with chronic irritability and hyperarousal. This syndrome has been called the "broad BD phenotype" or severe mood dysregulation (SMD). This study examines prevalence, concurrent Axis I diagnoses, and longitudinal outcome of SMD in an epidemiologic sample. METHODS: Data were drawn from the Great Smoky Mountains Study, a longitudinal epidemiological study. Items from the Child and Adolescent Psychiatric Assessment were used to generate SMD criteria. RESULTS: Among 1420 children, the lifetime prevalence of SMD in children ages 9-19 was 3.3%. Most (67.7%) SMD youth had an Axis I diagnosis, most commonly attention-deficit/hyperactivity disorder (26.9%), conduct disorder (25.9%), and/or oppositional defiant disorder (24.5%). In young adulthood (mean age 18.3 +/- 2.1 years), youth who met criteria for SMD in the first wave (mean age 10.6 +/- 1.4 years) were significantly more likely to be diagnosed with a depressive disorder (odds ratio 7.2, confidence interval 1.3-38.8, p = .02) than youth who never met criteria for SMD. CONCLUSIONS: Severe mood dysregulation is relatively common in childhood and predicts risk for early adulthood depressive disorders. Research should continue to explore the course of illness in children with SMD.

BACKGROUND: Although major depressive disorder (MDD) represents one of the most serious psychiatric problems afflicting adolescents, efforts to understand the neural circuitry of adolescent MDD have lagged behind those of adult MDD. This study tests the hypothesis that adolescent MDD is associated with abnormal amygdala activity during evocative-face viewing. METHODS: Using functional magnetic resonance imaging (fMRI), between-group differences among MDD (n = 10), anxious (n = 11), and non-psychiatric comparisons (n = 23) were examined during successful vs. unsuccessful face encoding, with encoding success measured post-scan. RESULTS: Compared to healthy adolescents, MDD patients exhibited poorer memory for faces. fMRI analyses accounted for this performance difference through event-related methods. In an analysis comparing successful vs. unsuccessful face encoding, MDD patients exhibited greater left amygdala activation relative to healthy and anxious youth. CONCLUSIONS: Given prior findings among adults, this study suggests that adolescent and adult MDD may involve similar underlying abnormalities in amygdala functioning.

OBJECTIVE: The Preschool ADHD Treatment Study (PATS) was a NIMH-funded, six-center, randomized, controlled trial to determine the efficacy and safety of immediate-release methylphenidate (MPH-IR), given t.i.d. to children ages 3 to 5.5 years with attention-deficit/hyperactivity disorder (ADHD). METHOD: The 8-phase, 70-week PATS protocol included two double-blind, controlled phases, a crossover-titration trial followed by a placebo-controlled parallel trial. The crossover-titration phase's primary efficacy measure was a combined score from the Swanson, Kotkin, Atkins, M-Flynn, and Pelham (SKAMP) plus the Conners, Loney, and Milich (CLAM) rating scales; the parallel phase's primary outcome measure was excellent response, based on composite scores on the Swanson, Nolan, and Pelham (SNAP) rating scale. RESULTS: Of 303 preschoolers enrolled, 165 were randomized into the titration trial. Compared with placebo, significant decreases in ADHD symptoms were found on MPH at 2.5 mg (p<.01), 5 mg (p<.001), and 7.5 mg (p<.001) t.i.d. doses, but not for 1.25 mg (p<.06). The mean optimal MPH total daily dose for the entire group was 14.2 +/- 8.1 mg/day (0.7+/-0.4 mg/kg/day). For the preschoolers (n=114) later randomized into the parallel phase, only 21% on best-dose MPH and 13% on placebo achieved MTA-defined categorical criterion for remission set for school-age children with ADHD. CONCLUSIONS: MPH-IR, delivered in 2.5-, 5-, and 7.5-mg doses t.i.d., produced significant reductions on ADHD symptom scales in preschoolers compared to placebo, although effect sizes (0.4-0.8) were smaller than those cited for school-age children on the same medication

The present study investigated the effect of ethanol (EtOH) exposure and its withdrawal on the central endocannabinoid system utilizing an EtOH vapor inhalation model, which is known to produce functional tolerance and dependence to EtOH. Swiss Webster mice (n=24) were exposed to EtOH vapors for 72h. Mice were sacrificed after 72h following EtOH exposure (n=12) and 24h after its withdrawal (n=12). Radioligand binding assays were performed to measure the density of CB(1) receptor and CB(1) receptor agonist-stimulated [(35)S]GTPgammaS binding in crude synaptic membranes isolated from the cortex, hippocampus, striatum and cerebellum. The density of CB(1) receptor was significantly decreased (31-39%) in all the brain regions when compared to the control group. The CB(1) receptor-stimulated G(i/o) protein activation was also found to be decreased (29-40%) in these brain regions of EtOH exposed mice. Recovery of the CB(1) receptor density, in addition to, the CB(1) receptor-mediated G-protein activation was observed after 24h withdrawal from EtOH. The levels of cortical anandamide, which was significantly increased (147%) by EtOH exposure, returned to basal levels after 24h of withdrawal from EtOH exposure. A significant reduction (21%) in the activity of fatty acid amide hydrolase was found in the cortex of EtOH administered mice. Taken together, the neuroadaptation in the EC system may have a potential role in development of tolerance and dependence to EtOH

Decades of research in the area of developmental psychobiology have shown that early life experience alters behavioral and brain development, which canalizes development to suit different environments. Recent methodological advances have begun to identify the mechanisms by which early life experiences cause these diverse adult outcomes. Here we present four different research programs that demonstrate the intricacies of early environmental influences on behavioral and brain development in both pathological and normal development. First, an animal model of schizophrenia is presented that suggests prenatal immune stimulation influences the postpubertal emergence of psychosis-related behavior in mice. Second, we describe a research program on infant rats that demonstrates how early odor learning has unique characteristics due to the unique functioning of the infant limbic system. Third, we present work on the rodent Octodon degus, which shows that early paternal and/or maternal deprivation alters development of limbic system synaptic density that corresponds to heightened emotionality. Fourth, a juvenile model of stress is presented that suggests this developmental period is important in determining adulthood emotional well being. The approach of each research program is strikingly different, yet all succeed in delineating a specific aspect of early development and its effects on infant and adult outcome that expands our understanding of the developmental impact of infant experiences on emotional and limbic system development. Together, these research programs suggest that the developing organism's developmental trajectory is influenced by environmental factors beginning in the fetus and extending through adolescence, although the specific timing and nature of the environmental influence has unique impact on adult mental health

This article presents the process used to develop a set of statewide positive youth development (YD) outcome indicators to complement existing adolescent well-being indicators in New York State (NYS). Intended uses included program and community-, county-, and state-level planning; grant writing; evaluation; and outcome monitoring in coordination with national YD-oriented initiatives. A common set of metrics, if adopted, would promote consistency and information sharing across levels and purposes. A workgroup of the NYS Youth Development Team reviewed existing indicators and accepted nominations from NYS stakeholders. Input from Youth Development Team members and national YD experts was used to narrow the list to 91. Forty-one NYS policy makers performed card sorts and ratings of the indicators, and a concept-mapping process, employing hierarchical cluster analysis, identified nine clusters of items. The policy makers, along with 121 NYS program providers and 91 young adults (aged 18-21) rated the indicators from 1 ('not important') to 5 ('very important'). All intergroup correlations of ratings were 0.93 or greater, and therefore responses were analyzed together. The concept map and mean indicator ratings were used to select a short list of 15 indicators. Although respondents were intentionally given a mix of problem-focused, risk-focused, and strength-based items, the highest rated items were almost exclusively strength based

Although positive youth development (PYD) is increasingly influential in the field of youth programming, core knowledge and competencies for youth workers continue to be defined. Youth serving agencies throughout the United States face serious obstacles in the creation of a stable and well-trained workforce, despite the presence of many talented and resourceful individuals who work with youth in the community. One strategy for organizational and staff development is through PYD-oriented, community-based partnerships designed to enhance youth worker knowledge and competence. Two different partnerships are described in this report. The first brought together experts in youth work, health, and trauma, and focused on improving youth worker response to psychologic trauma commonly experienced by urban youth. This partnership used an iterative reflective practice approach to describe best practices in youth work. The second partnership strategically taught evaluation skills to youth program consumers, AmeriCorps service members, and adult youth workers to advance youth-adult partnerships. These exemplars demonstrate that partnerships can drive systems for improving competencies in youth workers and the capacities of youth services