Faculty Bibliography

Fear extinction refers to the ability to adapt as situations change by learning to suppress a previously learned fear. This process involves a gradual reduction in the capacity of a fear-conditioned stimulus to elicit fear by presenting the conditioned stimulus repeatedly on its own. Fear extinction is context-dependent and is generally considered to involve the establishment of inhibitory control of the prefrontal cortex over amygdala-based fear processes. In this paper, we review research progress on the neural basis of fear extinction with a focus on the role of the amygdala and the prefrontal cortex. We evaluate two competing hypotheses for how the medial prefrontal cortex inhibits amygdala output. In addition, we present new findings showing that lesions of the basal amygdala do not affect fear extinction. Based on this result, we propose an updated model for integrating hippocampal-based contextual information with prefrontal-amygdala circuitry

BACKGROUND: School bullying is the most common type of school violence. Victimization by or perpetration of school bullying has frequently been associated with a broad spectrum of behavioral, emotional, and social problems. OBJECTIVE: To investigate the prevalence and demographic characteristics of victims, perpetrators, and victim-perpetrators in a Korean middle school sample. METHODS: We evaluated 1756 middle school students in this cross-sectional study. Students provided demographic information and completed the Korean-Peer Nomination Inventory. Descriptive statistics and the Pearson chi(2) test were used. RESULTS: We found that 40% of all children participated in school bullying. By category, the prevalence of victims, perpetrators, and victim-perpetrators was 14%, 17%, and 9%, respectively. The most common subtypes of victimization were exclusion (23%), verbal abuse (22%), physical abuse (16%), and coercion (20%). Boys were more commonly involved in both school bullying and all 4 types of victimization. The prevalence of bullying was greater in students with either high or low socioeconomic status and in nonintact families. CONCLUSIONS: School bullying is highly prevalent in Korean middle school students. Demographic characteristics can help identify students at greater risk for participation in school bullying

PURPOSE: To describe attitudes and practices of end-of-life care teaching in the undergraduate medical curriculum in the United States as reported by administrative leadership and identify opportunities for improvement. METHOD: A telephone survey of associate deans for medical education or curricular affairs at a random sample of 62 accredited U.S. medical schools was conducted in 2002. RESULTS: Fifty-one deans participated (82% response rate). Most (84%) described end-of-life care education as 'very important' and supported incorporating more end-of-life care teaching into the undergraduate curriculum. Sixty-seven percent reported that insufficient time is currently given to palliative care in their curriculum. Although a majority opposed required courses (59%) or clerkships (70%) that focused on end-of-life care, they did unanimously endorse integrating teaching end-of-life care into existing courses or clerkships. Key barriers to incorporating more end-of-life care into the curriculum included lack of time in the curriculum, lack of faculty expertise, and absence of a faculty leader. CONCLUSION: Associate deans for medical education or curricular affairs in the United States support integrating end-of-life care content into existing courses and clerkships throughout the undergraduate medical curriculum. Successful integration will require institutional investment in faculty development, including both the development of faculty leaders to drive change efforts, and the education of all faculty who teach students and exert influence as role models and mentors. The strong support for end-of-life care education expressed by academic leaders in this study, combined with the high level of interest expressed in the authors' 2001 national survey of students, provide evidence of the potential for meaningful change in the undergraduate medical curriculum

Depression is associated with alterations in hormone and catecholamine circadian rhythms. Analysis of these alterations has the potential to distinguish between three neurobiological models of depression, the catecholamine model, the phase advance model and the dysregulation model. Although a number of studies of 24-h rhythms have been reported, inconsistencies among the findings have complicated efforts to model the chronobiology of depression. The present study takes advantage of frequent plasma sampling over the 24-h period and a multioscillator cosinor model to fit the 24-h rhythms. METHOD: Plasma levels of norepinephrine, cortisol, prolacatin and growth hormone were sampled at 30-min intervals, and MHPG at 60-min intervals, over a 24-h period in 22 patients with major depressive disorder and 20 healthy control volunteers. RESULTS: The depressed patients had phase advanced circadian rhythms for cortisol, norepinephrine and MHPG, phase advanced hemicircadian rhythms for cortisol and prolactin, and a phase advanced ultradian rhythm for prolactin compared to healthy control subjects. In addition, the rhythm-corrected 24-h mean value (mesor) of norepinephrine was lower in the depressed patients compared to the healthy controls. There also was a poorer goodness-of-fit for norepinephrine to the circadian oscillator in the depressed patients relative to the healthy controls. CONCLUSIONS: These findings provide partial support for the dysregulation model of depression and are consistent with those studies that have found phase advances in cortisol, norepinephrine and MHPG rhythms in depression

INTRODUCTION: An expanding database supports the notion that the deficit syndrome (DS) is a discrete condition within schizophrenia and recent data argues that Smell Identification Deficits (SID) may have a primary relationship with its pathophysiology. If so, then the relationship of University of Pennsylvania Smell Identification Test (UPSIT) scores with other neurocognitive measures in DS patients may point to the neural substrate of the deficit syndrome. METHOD: We examined the relationship of UPSIT scores and Wechsler Adult Intelligence Scale-Revised (WAIS-R) performance in 46 DSM-IV schizophrenia patients. The Schedule for the Deficit Syndrome (SDS) interview was used to subgroup the sample into 13 DS and 33 nondeficit syndrome (NDS) patients. RESULTS: DS and NDS groups had similar mean ages, age of onset, and GAF scores, but DS patients had fewer years of education. DS and NDS patients also did not differ in full scale, verbal or performance IQ or in any WAIS-R subtest. However, UPSIT scores were significantly worse in the DS patients, most of whom met criteria for a clinically meaningful olfactory impairment. In DS patients, UPSIT scores were significantly correlated with Performance IQ, Block Design, and Object Assembly, all of which are associated with complex visual-motor organizational function thought to be mediated by parietal circuitry. UPSIT scores in NDS patients were significantly related with Vocabulary, Similarities, and Digit Symbol subtests, which are indicative of verbal functioning. CONCLUSION: These preliminary data support previous findings suggesting that in addition to frontal neuropsychological abnormalities, DS patients may have greater performance impairments on tasks associated with parietal functioning. Our findings furthermore suggest that the parietal circuitry may be a conspicuous substrate for impaired odor identification ability in these patients. The lesser abnormalities in UPSIT ability in NDS patients may be attributed to verbal ability. These data are preliminary and further investigations with larger samples are needed to support our findings

OBJECTIVE: To test the hypotheses that in children with attention-deficit/hyperactivity disorder (ADHD) (1) symptoms of ADHD, oppositional defiant disorder, and overall functioning are significantly improved by methylphenidate combined with intensive multimodal psychosocial treatment compared with methylphenidate alone and with methylphenidate plus attention control and (2) more children receiving combined treatment can be taken off methylphenidate. METHOD: One hundred three children with ADHD (ages 7-9), free of conduct and learning disorders, who responded to short-term methylphenidate were randomized for 2 years to (1) methylphenidate alone; (2) methylphenidate plus psychosocial treatment that included parent training and counseling, social skills training, psychotherapy, and academic assistance, or (3) methylphenidate plus attention psychosocial control treatment. Assessments included parent, teacher, and psychiatrist ratings, and observations in academic and gym classes. RESULTS: Combination treatment did not lead to superior functioning and did not facilitate methylphenidate discontinuation. Significant improvement occurred across all treatments and continued over 2 years. CONCLUSIONS: In stimulant-responsive children with ADHD, there is no support for adding ambitious long-term psychosocial intervention to improve ADHD and oppositional defiant disorder symptoms. Significant benefits from methylphenidate were stable over 2 years

OBJECTIVE: To describe the rationale, methodology, and sample characteristics of a dual-site treatment study (New York and Montreal) of children with attention-deficit/hyperactivity disorder (ADHD) conducted between 1990 and 1995. The hypotheses were that (1) methylphenidate combined with comprehensive multimodal psychosocial treatment was superior to methylphenidate alone in improving multiple functions and (2) the efficacy of the psychosocial intervention resulted from its specific components and not from nonspecific treatment effects. METHOD: One hundred three children with ADHD (ages 7-9), free of conduct and learning disorders, who responded to methylphenidate, were randomized for 2 years to (1) methylphenidate treatment alone; (2) methylphenidate combined with multimodal psychosocial treatment that included parent training and counseling, academic assistance, psychotherapy, and social skills training; or (3) methylphenidate plus attention control treatment that excluded specific aspects of the psychosocial intervention. Children were switched to single-blind placebo after 12 months; methylphenidate was reinstituted when clinically indicated. Assessments included ratings by parents, teachers, children, and psychiatrists; school observations in academic and gym classes; and academic performance tests. Almost 80% of families completed the 2-year study. Companion papers present treatment effects. CONCLUSIONS: A comprehensive 2-year psychosocial treatment was delivered successfully to children with ADHD and their families

This study investigated demographic and cognitive correlates of cued odor identification in a population-based sample from the Betula project: 1906 healthy adults varying in age from 45 to 90 years were assessed in a number of tasks tapping various cognitive domains, including cognitive speed, semantic memory and executive functioning. The results revealed a gradual and linear deterioration in cued odor identification across the adult life span. Overall, females identified more odors than men, although men and women performed at the same level in the oldest age cohort (85-90 years). Hierarchical regression analyses revealed that age, sex, education, cognitive speed and vocabulary were reliable correlates of performance in the odor identification task. In addition, age-related deficits in the included demographic and cognitive variables could not fully account for the observed age-related impairment in identification, suggesting that additional factors are underlying the observed deterioration. Likely candidates here are sensory abilities such as olfactory detection and discrimination.

In many altricial species, fear responses such as freezing do not emerge until sometime later in development. In infant rats, fear to natural predator odors emerges around postnatal day (PN) 10 when infant rats begin walking. The behavioral emergence of fear is correlated with two physiological events: functional emergence of the amygdala and increasing corticosterone (CORT) levels. Here, we hypothesize that increasing corticosterone levels influence amygdala activity to permit the emergence of fear expression. We assessed the relationship between fear expression (immobility similar to freezing), amygdala function (c-fos) and the level of corticosterone in pups in response to presentation of novel male odor (predator), littermate odor and no odor. CORT levels were increased in PN8 pups (no fear, normally low CORT) by exogenous CORT (3 mg/kg) and decreased in PN12 pups (express fear, CORT levels higher) through adrenalectomy and CORT replacement. Results showed that PN8 expression of fear to a predator odor and basolateral/lateral amygdala activity could be prematurely evoked with exogenous CORT, while adrenalectomy in PN12 pups prevented both fear expression and amygdala activation. These results suggest that low neonatal CORT level serves to protect pups from responding to fear inducing stimuli and attenuate amygdala activation. This suggests that alteration of the neonatal CORT system by environmental insults such as alcohol, stress and illegal drugs, may also alter the neonatal fear system and its underlying neural control