Faculty Bibliography

The current work sought to understand the ways in which family-level factors are related to youth's decisions regarding two hypothetical social dilemmas commonly faced by youth in high risk environments-deciding how to respond to persistent teasing and whether to intervene in a group fight. Specifically, the study focused on the relationship between African American youth's range of decisions on the two social dilemmas and five parenting practices previously identified as correlates to youth well-being. Analyses of data gathered from 118 African American youth and their caregivers revealed that only racial socialization parenting practices were significant factors against choosing escalating options on the two dilemma scenarios. These results add to the growing evidence of the positive effects of racial socialization upon African American youth. The current study highlights the importance of examining the ways in which racial socialization can enhance the decision-making of African American youth

Ketamine is a schedule III drug with a well-established safety profile that has been used extensively as an anesthetic for close to 4 decades. It has long been described as a drug of abuse and has become known as one of the 'club drugs,' used by adolescents and young adults in rave and circuit party settings. Ketamine is a congener of phencyclidine and acts as a noncompetitive N-methyl-D-aspartate (NMDA) antagonist. Through a complicated and not completely understood process, NMDA antagonism increases dopamine levels in reward-related areas such as the ventral tegmental area and the nucleus accumbens. In addition to its addictive liability, there is also evidence to suggest that ketamine might have anti-addictive properties when used as an adjunct to psychotherapy that takes advantage of its ability to produce spiritually oriented altered states of consciousness. This technique has been applied to patients with alcohol and opiate use disorders. Ketamine's potential anti-addictive properties can be understood by looking at biologic and psycho-spiritual models

A common problem in statistical modelling is to distinguish between finite mixture distribution and a homogeneous non-mixture distribution. Finite mixture models are widely used in practice and often mixtures of normal densities are indistinguishable from homogenous non-normal densities. This paper illustrates what happens when the EM algorithm for normal mixtures is applied to a distribution that is a homogeneous non-mixture distribution. In particular, a population-based EM algorithm for finite mixtures is introduced and applied directly to density functions instead of sample data. The population-based EM algorithm is used to find finite mixture approximations to common homogeneous distributions. An example regarding the nature of a placebo response in drug treated depressed subjects is used to illustrate ideas

BACKGROUND: A substantial proportion of children with attention-deficit/hyperactivity disorder (ADHD) show deficits on inhibitory control tests. However, questions remain about (i) the extent of these deficits across different inhibitory domains, (ii) their relationship to deficits in non-executive processes and (iii) whether they extend into adolescence. METHODS: Seventy-seven children and adolescents with ADHD and 50 non-ADHD controls completed three inhibitory tasks, a simple two choice RT task (2CR) and an IQ assessment. RESULTS: ADHD was moderately associated with deficits on all tasks (effect sizes d=0.5-0.9). Deficits were equally marked in childhood and adolescence. Inhibitory deficits were not associated with IQ and, although reduced substantially, remained significant after performance on a simple reaction time task was controlled for statistically. DISCUSSION: In highlighting the significant, but limited, role of inhibitory deficits in ADHD, these results are consistent with recent accounts that emphasize the neuropsychological heterogeneity of this condition

The study assessed conduct and emotional difficulties in a group of Romanian adoptees at age 11, and serves as a follow-up to assessments made when the children were 6 years old. It was found that there was a significant increase in emotional difficulties, but not conduct problems, for the Romanian sample since age 6. It was also found that emotional difficulty was significantly more prevalent at age 11 in the Romanian group than in a within-UK adoptee group. Emotional difficulties in the Romanian adoptee group were found to be significantly and strongly related to previous deprivation-specific problems (disinhibited attachment, cognitive impairment, inattention/overactivity and quasi-autism); however, the presence of such early problems did not account fully for the onset of later emotional problems. Five contrasting hypotheses concerning possible mediators for later onset of emotional difficulties for the Romanian group were examined. No links were found to duration of deprivation or other deprivation-related indices, stresses/difficulties in the postadoption family environment, or educational attainment and self-esteem. There was some evidence that emotion recognition might play a role in the emergence of these problems, but other measures of social competence and theory of mind showed no associations with the onset of emotional problems