Increases in ethanol ingestion by young rats following interaction with intoxicated siblings: A review

Although there are a variety of animal models used in alcoholism research, there has been very little experimental investigation into possible environmental/experiential factors leading to an initial bout of alcohol ingestion. Adolescent alcohol abuse is a major problem in today's society and research is beginning to focus on the predisposing conditions toward alcohol consumption, particularly in this vulnerable age group. The results of recent research from our laboratory are reviewed in which voluntary ingestion of ethanol by preweanling and adolescent rats is increased following exposure to an intoxicated sibling. This paradigm centers on the notion that rodents, and perhaps other mammalian species as well, acquire information about foods to ingest based in part on interaction with a conspecific that has recently ingested a novel diet (e.g. Galef, 1981). Smelling food-derived cues on the breath of another animal is known to affect later food choice. The procedures described in this paper represent a potential new model for examining the effects of early exposure to ethanol through social interactions on the initiation of voluntary alcohol ingestion.     

Personality characteristics of adolescent marijuana users

A group of high school students from middle- to upper-middle-class backgrounds was studied to investigate the relationship between marijuana use, marijuana misuse, and personality. The California Personality Inventory and a version of the Adolescent Alcohol Involvement Scale (adapted for the assessment of marijuana involvement) were the primary instruments used. Analysis of variance and regression analysis were performed on the data. Results indicated a relationship between the personality characteristics of adolescents who are involved in marijuana use and misuse and adolescents who are not; there are discernible differences in the personalities of the adolescents who are involved with marijuana. The intervention and prevention implications of these results are discussed.     

ICU谵妄患者病因分析以及处理

分析急诊ICU患者出现谵妄症状的原因以及处理对策。分析总结我院急诊ICU3年间所有患者的资料,发现20．2％的患者出现谵妄症状,原因为：（1）疾病相关;（2）药物相关;（3）监护环境等多种因素作用结果。经过调整治疗方案、加强心理护理后,需要镇静药物的仅为谵妄患者的19．7％。因此寻找谵妄原因很重要,治疗重点在于去除谵妄原因以及相关促发因素。     

Return of experimentally induced chocolate craving after extinction in a different context: divergence between craving for and expecting to eat chocolate

Unlike in fear conditioning, little attention has been devoted to extinction and renewal in appetitive conditioning, despite its relevance for extinction-based addiction treatments. We developed a paradigm, using a specific tray as a conditioned stimulus (CS) for eating chocolate (unconditioned stimulus, US), to investigate the effects of context change on acquisition and extinction of conditioned chocolate craving using an ABA renewal design. In Study 1 (n=32), participants successfully acquired chocolate craving, but unlike what is commonly observed in fear conditioning, craving did not extinguish. In Study 2, we separately assessed craving and US expectancy in a between-subjects design (n=64). US-expectancy data showed acquisition, extinction and renewal in the ABA group. The craving data did not follow this pattern, suggesting different mechanisms for craving and US expectancy. Similarities and differences between craving and US expectancy, as well as practical implications, are discussed.     

ICU谵妄患者病因分析以及处理

分析急诊ICU患者出现谵妄症状的原因以及处理对策.分析总结我院急诊ICU 3年间所有患者的资料,发现20.2％的患者出现谵妄症状,原因为:(1)疾病相关；(2)药物相关；(3)监护环境等多种因素作用结果.经过调整治疗方案、加强心理护理后,需要镇静药物的仅为谵妄患者的19.7％.因此寻找谵妄原因很重要,治疗重点在于去除谵妄原因以及相关促发因素.     

Medial temporal and prefrontal lobe activation during verbal encoding following glucose ingestion in schizophrenia: A pilot fMRI study

Verbal declarative memory is one of the most reliably impaired cognitive functions in schizophrenia. Important issues are whether the problem is reversible, and which brain regions underlie improvement. We showed previously that glucose administration improved declarative memory in patients with schizophrenia, and sought in this pilot study to identify whether glucose affects the location or degree of activation of brain regions involved in a verbal encoding task. Seven clinically stable and medicated patients with schizophrenia or schizoaffective disorder, who showed deficits on a clinical test of memory, participated in the study. Subjects served as their own controls in a double-blind, crossover protocol that consisted of two sessions about a week apart. In each session, subjects ingested a beverage flavored with lemonade that contained 50 g of glucose on one occasion, and saccharin on the other. Blood glucose was measured before and 15, 50, and 75 min after ingestion. After ingesting the beverage, they performed a verbal encoding task while undergoing brain functional magnetic resonance imaging. The results showed significantly greater activation of the left parahippocampus during novel sentence encoding in the glucose condition, compared to the saccharin condition, despite no change in memory performance. A trend towards greater activation of the left dorsolateral prefrontal cortex (p<.07) was also evident in the glucose condition. These pilot findings emphasize the sensitivity of both the medial temporal and prefrontal regions to effects of glucose administration during encoding, and are consistent with the hypothesis that these regions also participate in declarative memory improvements following glucose administration.     

An illusion of ingestion

Three experiments were conducted to find out why subjects ingest substantially more liquid than required when asked to match a visually displayed volume. All three experiments replicated the basic illusion phenomenon, and Experiments 1 and 2 indicated that it was attributable to the subjects’ underestimating the volume of liquid in their mouths. Experiment 3 revealed that the illusion was not present with solid substances, but it was evident with liquids when a quite different measurement procedure was employed.     

The effects of marijuana on human physical aggression

Thirty male undergraduates received intense provocation following their ingestion of one of three doses of delta-9-tetrahydrocannabinol (THC). The subjects in the low-dose condition tended to respond in a more aggressive manner than the subjects in the moderate-and high-dose conditions. The subjects in the high-dose condition behaved in a relatively nonaggressive manner throughout the experimental session.     

Tridimensional personality traits of college student marijuana users

The present study examined the possibility that marijuana use among college students might be associated with particular personality traits. College student volunteers (N = 176) were administered the Tridimensional Personality Questionnaire and a drug-use questionnaire. Analysis of variance showed that the mean score on Novelty Seeking was significantly higher and on Persistence significantly lower among lifetime marijuana users than among nonmarijuana using peers. Programs for prevention among college students may be enhanced by approaches tailored to individuals scoring high on Novelty Seeking and low on Persistence.     

Driving after use of alcohol and marijuana in college students.

Driving after use of marijuana is almost as common as driving after use of alcohol in youth (P. M. O'Malley & L. D. Johnston, 2003). The authors compared college students' attitudes, normative beliefs and perceived negative consequences of driving after use of either alcohol or marijuana and tested these cognitive factors as risk factors for substance-related driving. Results indicated that youth perceived driving after marijuana use as more acceptable to peers and the negative consequences as less likely than driving after alcohol use, even after controlling for substance use. Results of zero-inflated Poisson regression analyses indicated that lower perceived dangerousness and greater perceived peer acceptance were associated with increased engagement in, and frequency of, driving after use of either substance. Lower perceived likelihood of negative consequences was associated with increased frequency for those who engage in substance-related driving. These results provide a basis for comparing how youth perceive driving after use of alcohol and marijuana, as well as similarities in the risk factors for driving after use of these substances.     

Maturational changes in Canadian adolescents' cognitive attitudinal structure concerning marijuana

Thirty-four items concerning marijuana use were administered three times to a cohort of Canadian high school students between Grades 11 and 13, in 1977 (n = 439), 1978 (n = 419), and 1979 (n = 167). These items were designed to measure four distinct constructs: attitude, perceived peer approval or disapproval, concern about risks, and symbolic protest against conventional society. A cross-sectional factor analysis of the Grade 13 data supported the hypothesized factor structure, as had earlier work with college students. However, analogous analyses on the Grade 11 and Grade 12 data contradicted the hypothesized factor structure. Most notably, separate factors for positive and negative attitude appeared in the Grade 11 and 12 analyses. The data were interpreted primarily in terms of maturational changes, largely through elimination of alternative interpretations by internal analyses and previous findings. Implications were discussed for adolescent cognitive-attitudinal development, attitude theory, and analysis of panel data.     

Further tests of a meta-model of youthful marijuana use

This paper tests a meta-model of youthful marijuana use on students in Grades 11, 12 and 13. Although the specific models for each grade varied in detail, all followed a meta-model making the following assumptions: (1) that use or nonuse of marijuana depends primarily on attitude towards use; (2) that attitude largely reflects the perceived functional and dysfunctional consequences of use; and (3) that what people perceive as functional or dysfunctional depends on relevant personality characteristics. All three models showed satisfactory goodness-of-fit in terms of nonsignificant overidentification tests (minimum P > 0.25) and small discrepancies between observed correlations and the corresponding theoretically implied correlations. A notable feature of the Grade 13 data in contrast to those for Grade 12 and previously reported findings was the seeming unimportance of the perceived value of marijuana use for gaining acceptance from peers. It was suggested that this might reflect the selective survival into Grade 13 in the sampled community of more independently-oriented students.     

Age of onset of marijuana use and executive function

[Correction Notice: An Erratum for this article was reported in Vol 26(3) of Psychology of Addictive Behaviors (see record 2011-29227-001). Figure 1 should have been presented in color. All versions of this article have been corrected.] Marijuana (MJ) remains the most widely abused illicit substance in the United States, and in recent years, a decline in perceived risk of MJ use has been accompanied by a simultaneous increase in rates of use among adolescents. In this study, the authors hypothesized that chronic MJ smokers would perform cognitive tasks, specifically those that require executive function, more poorly than control subjects and that individuals who started smoking MJ regularly prior to age 16 (early onset) would have more difficulty than those who started after age 16 (late onset). Thirty-four chronic, heavy MJ smokers separated into early and late onset groups, and 28 non-MJ smoking controls completed a battery of neurocognitive measures. As hypothesized, MJ smokers performed more poorly than controls on several measures of executive function. Age of onset analyses revealed that these between-group differences were largely attributed to the early onset group, who were also shown to smoke twice as often and nearly 3 times as much MJ per week relative to the late onset smokers. Age of onset, frequency, and magnitude of MJ use were all shown to impact cognitive performance. Findings suggest that earlier MJ onset is related to poorer cognitive function and increased frequency and magnitude of MJ use relative to later MJ onset. Exposure to MJ during a period of neurodevelopmental vulnerability, such as adolescence, may result in altered brain development and enduring neuropsychological changes. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Adolescent marijuana use: the role of the physician

Adolescent marijuana use is an issue of concern to the community at large. Physicians now have the technology to identify marijuana use and thus are in a unique position to deal with the issue. This article addresses the moral issues related to screening and surveillance of adolescent marijuana use and postulates the justification for active physician intervention.