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Biomedical subjects

M D Newcomb

Publications and source records attributed to M D Newcomb.

At least 19 recordsLinked to original sources
PubMed1992

Substance abuse and control in the United States: ethical and legal issues.

In 1986, the United States began to wage its most recent War on Drugs. This has involved establishing various policies and making investments to implement these policies and approaches. In general, the U.S. has taken a tough-guy stand to drug abuse and control that emphasizes punishment, restriction, and 'social warfare', as opposed to a public health oriented position. Current policy reflects a 'quick fix' solution to a complex problem, which may partially explain its failure and why we appear to be losing the War on Drugs. In this review I summarize the current debates and controversies surrounding drug abuse in the U.S. regarding the extent of the drug problem, the need for drug control, prevention efforts, legalization controversy, workplace strategies, treatment dilemmas, and maternal drug abuse. I argue that a radically different approach must be taken that is grounded in public health methods and an appreciation of the larger social context in which drug abuse occurs. We must look for a long-term solution to this complex problem that is integrated into society, and which is certainly resistant to the current quick fix approaches.

Cross-Sectional Studies↗
PubMed1992

General deviance syndrome: expanded hierarchical evaluations at four ages from early adolescence to adulthood.

Problem behavior theory predicts that norm-violating attitudes and activities reflect a syndrome. Hierarchical latent-factor models examined the integrity of this syndrome at 4 developmental stages from early adolescence to adulthood. Latent constructs of Drug Use, Academic Orientation, Social Conformity, Criminal Behavior, and Sexual Involvement were assessed up to 4 times at 4-year intervals in a community sample. Second-order constructs of General Deviance confirmed integrity of the syndrome at these life stages, although subtle changes in certain components of the construct emerged. Criminal Behavior was more determined by General Deviance in adulthood than in young adulthood, whereas Sexual Involvement became less determined by the common factor between these times. Drug Use and low Social Conformity were consistently strong indicators of General Deviance.

Achievement↗
PubMed1992

Multiple protective and risk factors for drug use and abuse: cross-sectional and prospective findings.

A conceptual elaboration was developed that incorporates many risk and protective factors, and both direct and moderating (buffering) influences on drug involvement were tested. From prospective data, 14 factors related to drug use were selected and assigned empirically to either a multiple protective index (PFI) or a risk factor index (RFI). Analyses examined the relationships of the RFI, PFI, and their interaction on measures of cigarette, alcohol, cannabis, cocaine, and hard drug use cross-sectionally in late adolescence and later in young adulthood. These same variables were used to predict alcohol, cannabis, and cocaine abuse 8 years later. Vulnerability as measured by the RFI, PFI, and their interaction was highly associated with drug use in adolescence, moderately associated with certain types of drug use in young adulthood, and strongly associated with heightened drug problems in adulthood.

Adolescent↗
PubMed1992

Social status and drunk-driving intervention.

The decision to intervene to prevent an inebriated peer from driving drunk is examined in a survey administered to one lower division and two upper division university classes. Of the 303 students who had been in a situation in which someone was too drunk to drive, 65% reported having intervened. Differences in the likelihood of intervention are examined through a log-linear analysis of the age, race and sex of the respondent and the potential drunk driver. The decision to intervene is seen as a naturally occurring form of helping behavior. Two hypotheses derived from the literature on helping behavior are examined: (1) persons are more likely to intervene with persons of lower status in terms of age, race and sex than with persons of higher status and (2) persons are more likely to intervene with those who are similar to themselves in terms of age, race and sex than with those who are different. Analysis reveals that persons are much more likely to experience drunk-driving situations in which the potential driver is similar to them in terms of these social characteristics than situations in which the driver is different. However, neither status differences nor similarity affects the likelihood of intervention.

Alcoholic Intoxication↗
PubMed1992

Interactive and higher-order effects of social influences on drug use.

The study of moderators and higher-order effects of social influences on drug use has many implications for theories of health behavior. In the present study, we investigated the longitudinal predictive effects of some of the prominent moderator variables that represent forms of susceptibility toward social influence in teenage drug use. We also studied the possibility that social influence may predict drug use in nonlinear (quadratic) forms, consistent with theories proposing that threshold or decelerating effects may occur in social influences on normatively sanctioned behaviors. Results showed that several of the interactive and quadratic predictive effects were significant. The findings supported the views that certain moderator variables act as buffers, which either protect the individual from social pressures to use drugs, or make the individual more susceptible to such pressures. In addition, two of the obtained quadratic effects of social influence lent support to the application of social impact theory to drug use. Overall, our findings suggest that interactive and nonlinear approaches to social influences on drug use provide a unique and viable theoretical perspective from which to construe this problem health behavior.

Adolescent↗
PubMed1991

Differentiation of early adolescent predictors of drug use versus abuse: a developmental risk-factor model.

Many psychosocial factors are associated with adolescent drug use, though most have not been tested as true predictors of drug use in prospective studies. Studies to date have also not differentiated predictors of drug use from abuse and have not addressed differential effects for specific substances. To address these concerns, we expanded the multiple risk-factor approach using 2-year longitudinal data from a sample of seventh graders. Frequencies of use for alcohol, cigarettes, marijuana, cocaine, and hard drugs were assessed at Time 1 and Time 2 and used to reflect latent constructs of polydrug use. From a set of 29 risk factors, unique predictors of any substance were separated conceptually according to whether they most related to initiation/experimental or problem/heavy drug use and were then summed into two-unit weighted indexes at each time. Distribution-free structural equation models were used to accommodate the nonnormal distributions of the illicit drug use measures. The problem risk index was strongly correlated with polydrug use at Time 1 and increased polydrug use at Time 2. Several specific relationships between risk and drug use across time also were noted.

Adolescent↗
PubMed1991

Cognitive motivation and drug use: a 9-year longitudinal study.

The predictive precedence of expectancy constructs, operationally defined as cognitive motivations, and drug use was investigated over a 9-year period from adolescence to adulthood. Alternative predictions from three different classes of theories of expectancy-behavior relations, including expectancy theory, a Skinnerian approach, and a reciprocal determinism perspective, were evaluated. The results are most consistent with the notion based in expectancy theory that cognitive motivations are nonspurious and possibly functionally autonomous influences on the use and abuse of drugs. More limited support is found for the view that drug use leads to cognitive motivations, as postulated in other theoretical perspectives. Other findings reveal the presence of expectancy generalization processes consistent with Rotter's (1954) expectancy theory, as well as the unique status of cognitive motivations for alcohol as an independent predictor of problem drug use.

Adolescent↗
PubMed1991

Personality, problem drinking, and drunk driving: mediating, moderating, and direct-effect models.

Three different general explanations of the effect of personality on problems from drinking alcohol were investigated. One general explanation involved mediating effects. The 2nd explanation involved direct effects of personality. The 3rd general personality process held that alcohol consumption and personality interact as moderating effects on drinking problems. Results provided support for each of the 3 general explanations of personality effects, although certain effects were found primarily for only 2 of the 6 personality constructs investigated (sensation seeking and cognitive motivation). These findings helped delimit the personality processes associated with drinking problems and demonstrated the viability of several specific processes that go beyond traditional assumptions about personality and problem drinking.

Adult↗
PubMed1991

Influence of sensation seeking on general deviance and specific problem behaviors from adolescence to young adulthood.

Indicators of a Sensation Seeking latent construct were assessed during adolescence and used to predict changes in repeatedly gathered measures of a latent construct of General Deviance. A community sample of 595 male and female Ss was assessed 3 times over a 5-year period from late adolescence to young adulthood. Most Ss reported use of licit drugs, about one half had tried illicit drugs, and a substantial minority had engaged in other delinquent or criminal activities. The General Deviance construct was stable over time, although specific cross-effects were found. Sensation Seeking was moderately correlated with General Deviance at all 3 levels but did not predict directly the General Deviance construct over time; the effects of Sensation Seeking on later deviant behavior and attitudes were specific rather than general.

Adolescent↗
PubMed1991

Effect of energy source fed to sows during late gestation on neonatal blood metabolite homeostasis, energy stores and composition.

Four experiments utilizing 49 primiparous and 34 multiparous sows were conducted to evaluate the effect of feeding either starch, soybean oil or medium-chain triglyceride (MCT) during late gestation (d 100 to parturition) on neonatal fasting blood glucose homeostasis (Exp. 1 and 2), d-100 maternal circulating insulin, glucagon and glucose concentrations (Exp. 3 and 4), neonatal energy stores (Exp. 3 and 4) and colostrum composition (Exp. 1, 2, 3 and 4). In all cases, sows were fed 7.2 Mcal/d of a diet that supplied 279 g of protein daily. During fasting, pigs from MCT-fed dams had higher blood glucose concentrations (P less than .05) than pigs from starch-fed dams. No differences between treatments were observed for total carcass fat, liver glycogen or carcass glycogen of pigs killed prior to suckling. In general, colostrum fatty acid profiles were influenced by diet; however, the shifts in fatty acids differed for experiments. Starch-fed sows had higher blood insulin and lower blood glucagon (P less than .05) than lipid-supplemented sows; however, sow blood glucose remained constant across treatments. This study indicates that any positive effects of feeding soybean oil to sows during late gestation are most likely mediated by a change in fatty acid composition of colostrum; any beneficial properties of MCT feeding most likely are mediated through improved blood glucose maintenance of the neonate when it is subjected to fasting conditions.

Animal Feed↗
PubMed1989

Substance use and abuse among children and teenagers.

During the past several years, there has been a renewed national concern about drug abuse, culminating in the current "war on drugs." In this review, we emphasize that even though child or teenage drug use is an individual behavior, it is embedded in a sociocultural context that strongly determines its character and manifestations. Our focus is on psychoactive substances both licit (cigarettes and alcohol) and illicit (e.g., cannabis and cocaine). We feel that it is critical to draw a distinction between use and abuse of drugs and to do so from a multidimensional perspective that includes aspects of the stimulus (drug), organism (individual), response, and consequences. Our selective review of substance use and abuse among children and adolescents covers epidemiology (patterns and extent of drug use), etiology (what generates substance use), prevention (how to limit drug use), treatment (interventions with drug users), and consequences (effects and outcomes of youthful drug use).

Adolescent↗
PubMed1989

Cigarette smokers do more than just smoke cigarettes.

In this study, we hypothesized that light and moderate-to-heavy cigarette smokers, when compared with nonsmokers, would exhibit significantly less healthy attitudes and behaviors on several dimensions relevant to the risk of coronary heart disease (CHD). A factor analysis of survey items measuring knowledge, attitudes, and behaviors in five CHD risk areas produced four major factors, which we labeled Attitudes (Factor 1), Health Consciousness (Factor 2), Knowledge (Factor 3), and Unhealthy Behaviors (Factor 4). Factor-based scales generated for each of these four factors were used in a one-way multivariate analysis of variance to examine differences between nonsmokers, light smokers, and moderate-to-heavy smokers. Cigarette smokers versus nonsmokers exhibited less positive attitudes toward CHD risk behaviors, whereas moderate-to-heavy cigarette smokers, as compared with the light smokers and the nonsmokers, exhibited lower levels of health consciousness and enacted unhealthy behaviors at a greater frequency. The moderate-to-heavy cigarette smokers also exhibited a lower commitment to enact healthy behavioral changes in the immediate future, even after corrections were introduced for their lower frequency of healthy behaviors during the past week. Overall, these results support our hypothesis that cigarette smokers, particularly as they become more involved with cigarette smoking, do more than just smoke cigarettes; they exhibit a less healthy lifestyle as shown by cognitive, behavioral, and motivational dimensions related to cardiovascular health.

Adolescent↗
PubMed1989

Assessment of nuclear anxiety among American students: stability over time, secular trends, and emotional correlates.

Studies of reactions and attitudes toward nuclear war have progressed from the use of anecdotal evidence to multi-item psychological measures. Additional psychometric data and substantive results of the Nuclear Attitudes Questionnaire (NAQ; Newcomb, 1986) are reported here. Data from three independent samples of students from the United States collected in 1984, 1986, and 1987 were compared and contrasted. The 1986 data were obtained immediately following the Chernobyl nuclear power plant accident. Test-retest reliability of the NAQ items and subscales was quite high and comparable among samples and established the across-time stability of the measure. There were several secular trends across years on items and subscales, indicating some increased concern about nuclear power (particularly in 1986), but also a general increase in nuclear concerns, fears, and anxiety. Anticipated sex differences were found on many of the NAQ items and subscales. Correlations between the NAQ subscales and the nine SCL-90-R scales (Derogatis, 1977) were consistent for the 1986 and 1987 samples. In latent variable analyses, a general factor of Emotional Distress was significantly correlated with a general factor of Nuclear Anxiety, as well as specifically with nuclear concern and fear for the future.

Adult↗
PubMed1989

Predicting changes in teenage drug use: the role of intention-behavior discrepancy.

This research investigated the role of intention-behavior discrepancy in predicting changes in drug use by American teenagers. The tested behavior included drinking alcohol, smoking cannabis, and taking hard drugs. Data were collected from 1,177 young adolescents at two time points separated by one year. Two sets of analysis were performed--a multitrait-multimethod latent variable model and longitudinal analyses. The results of longitudinal analyses indicated that, although young adolescents were legally and socially prohibited from engaging in drug-taking activities, some of them intended to use drugs. This discrepancy between behaviors and intentions decreased neither drug-taking behaviors nor intentions to use drugs over time; on the contrary, it increased adolescents' illegal drug use and intention to engage in such behaviors as predicted by Brehm's reactance theory. This discrepancy factor was a better predictor of later drug-taking behavior and positive intentions to use drugs than early intentions alone. The best predictor of later behavior and intentions was prior drug use.

Adolescent↗
PubMed1988

Adolescent drug use and intention to use drugs: concurrent and longitudinal analyses of four ethnic groups.

Concurrent and longitudinal analyses of the associations between intention to use and actual use of substances were examined for 847 adolescents from four different ethnic backgrounds. Five different substances were studied: Cigarettes, alcohol, cannabis, nonprescription medications, and hard drugs. Results showed that: (a) there were significant and consistent relationships between current level of substance use and intention of use for all ethnic groups. However, these measures of association varied considerably among ethnic groups and covered a wide range from .17 for Blacks on use of nonprescription medications to .69 for Hispanics on alcohol consumption; (b) the degree of association between intention and use, as well as ethnic differences gradually decreased over time; and (c) partialling out the effects of previous experimentation with drugs decreased the contribution of intention to predict future drug use to a nonsignificant level for Hispanics, to a moderate degree for Black and Asians, and remained a significant and meaningful contribution for Whites.

Adolescent↗
PubMed1988

Risk factors for substance use: ethnic differences among adolescents.

Risk factors for drug and alcohol use and abuse were studied among Hispanic, black, Asian, and white adolescents. The number of risk factors was a significant correlate of prevalence and heavy use among all adolescents, though the effects were stronger for some drug/ethnic group combinations. For example, the association between the number of risk factors and frequency of hard drug use was substantially smaller for blacks, compared to the other three ethnic groups. Risk factors were causal influences for increasing drug use, while controlling for initial level of use, among Hispanics and whites. However, these effects for blacks and Asians were in the same direction but not significant and were not significantly different from Hispanics and whites. Implications for prevention and intervention are discussed.

Adolescent↗