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Examines whether the reinforcing properties of drugs of abuse were altered in adulthood by methylphenidate, more commonly known as Ritalin. Subjects were 108 rats of Sprague-Dawley descent (Harlan). Methylphenidate, or saline was administered daily to the subjects from the postnatal period (11-20 days old). The rats preference for morphine during early adulthood was measured using conditioned place preference. The number of dopamine D₂ receptors was measured in each rat and the correlation between receptor number and morphine preference was determined. Results indicate that rats pretreated with methylphenidate showed greater preference for morphine than saline pretreated rats and suggests that exposure to methylphenidate during the postnatal period increases the rewarding value of morphine.

Adolescent drug use motivations were examined from the perspective of Erik Erikson's psychosocial theory (1963; 1968) of human development. The study used an existing data base derived from a sample of about 13,000 Arizona students in grades seven through twelve. Two questions were asked. The first examined the students' self-reported perceptions of drug use/nonuse motivations across the four ego-identity stages of Marcia (1966). The second examined drug use motivational perceptions within the four stages. First, approximately 13,000 Young People Survey (Jones, 1986) respondents were classified into the four ego-identity stages for each of two domains, Interpersonal and Ideological (Grotevant & Adams, 1984), according to rules suggested by Adams (1979). A random sample of approximately 200 of these respondents was then selected for the analyses for each of eight categories: Interpersonal achievement, moratorium, foreclosure, and diffusion; and Ideological achievement, moratorium, foreclosure, and diffusion. Subject responses to two survey questions were analyzed for the first research question. One survey question had asked the students why they thought people their age used drugs and alcohol, the second survey question asked students who had not used alcohol why they had not done so. The eight analyses revealed that the reported motivations were significantly different (p < .05) across all four ego-identity stages for both domains. The second research question analyzed responses to the survey question dealing with drug use motivations, and tested whether motivational responses discriminated marijuana users from nonusers within each of the four ego-identity stages. Each analysis produced statistically significant results. For achieved subjects, peers, recreation, and curiosity combined to discriminate marijuana users from nonusers (p < .05). For moratorium subjects, it was peers, recreation, and stress (p < .05). For foreclosed subjects, peers, curiosity, and recreation discriminated between users and nonusers (p < .05); and for diffused subjects, it was peers, boredom, and recreation (p < .05). The study indicates that young people use psychoactive substances for reasons which vary according to their level of ego-identity development (psychosocial maturity). Additionally, the study indicates that adolescent drug use motivations also depend upon their experience with drugs.

The purpose of this study was to assess the prevalence of crack use among adolescents living in a large southwestern city, and to study relationships between crack use and marijuana use. This included investigating reasons as well as associated circumstances for both crack use and marijuana use; and whether marijuana use would predict crack use. High school seniors (N = 269) were asked to disclose information about their marijuana (and hashish) use and non-use, and crack use and non-use. Preliminary computation of the results revealed only 2.6% of respondents indicating crack use; thus statistical analysis of that data was not warranted. Computation of the results indicated 34% of respondents reporting marijuana use; therefore, the focus of the study shifted to marijuana exclusively, resulting in a final sample size of n = 92. Two specific phenomena were investigated: crack use and marijuana use. Discriminant analysis of the data was performed to (1) measure differences in frequencies (indicated as "seldom" and "occasionally") of respondents' marijuana use a predicted by particular circumstances and reasons for its use; and (2) to measure whether students' marijuana use would predict crack use. Statistical significance using Chi square and canonical correlation was calculated for each set of variables. Chi square (5) = 46.10 yielded significance (p <.001) for five of nine circumstances as predictors of marijuana use: "At a party" was the best discriminating variable. Chi square (4) = 36.73 yielded significance (p <.001) for four of thirteen reasons as predictors of marijuana use; "To get high" was the best discriminating reasons variable. The study succeeded in determining several drug-related attributions: (1) there is one-third less prevalence of crack use among adolescents in the area being researched than is reported nationally; (2) there is about the same prevalence of marijuana use as nationally reported; (3) there are specific associated circumstances which predict frequency of marijuana use; and (4) there are specific associated reasons which predict frequency of marijuana use. Finally, although it is not data-based, marijuana appears to be a predictor of crack use, i.e., all seven crack users reported having used marijuana prior to crack use.

An Attitude Survey consisting of 70 variables was administered to 1007 Indiana high school students. This sample came from public, parochial, and private schools. The survey was designed to investigate the backgrounds, attitudes, and personality characteristics of the high school drug user.Significant correlates of high school drug use were: sex, age, and grade in school, mother working outside the home, lack of closeness to family members, and parental drinking, smoking, and medicating habits. Users tended to identify strongly with their peers and depend upon them. They generally exhibited a negative attitude toward school and authority, a pessimistic assessment of life in general and of their own futures, and a positive evaluation of the effects of drugs.The high school drug user’s personality was marked by: depression, anxiety, low self-esteem, self-seeking, and a lack of religiosity. They also combined multiple personal worries and fears with few effective coping mechanisms.

This study examined the effect of preweanling methyphenidate exposure on later drug reward. We examined the induction, extinction, and reinstatement of morphine induced conditioned place preference (CPP) in rats that received methylphenidate pretreatment during the preweanling period.