Browsing by Subject "Central Nervous System Stimulants"

Now showing 1 - 5 of 5
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    Effects of sub-chronic methylphenidate on risk-taking and sociability in zebrafish (Danio rerio).
    (Naunyn-Schmiedeberg's archives of pharmacology, 2020-08) Brenner, Rebecca G; Oliveri, Anthony N; Sinnott-Armstrong, Walter; Levin, Edward D
    Attention deficit hyperactive disorder (ADHD) is the most common psychiatric disorder in children affecting around 11% of children 4-17 years of age (CDC 2019). Children with ADHD are widely treated with stimulant medications such as methylphenidate (Ritalin®). However, there has been little research on the developmental effects of methylphenidate on risk-taking and sociability. We investigated in zebrafish the potential developmental neurobehavioral toxicity of methylphenidate on these behavioral functions. We chose zebrafish because they provide a model with extensive genetic tools for future mechanistic studies. We studied whether sub-chronic methylphenidate exposure during juvenile development causes neurobehavioral impairments in zebrafish. Methylphenidate diminished responses to environmental stimuli after both acute and sub-chronic dosing. In adult zebrafish, acute methylphenidate impaired avoidance of an approaching visual stimulus modeling a predator and decreased locomotor response to the social visual stimulus of conspecifics. Adult zebrafish dosed acutely with methylphenidate demonstrated behaviors of less retreat from threatening visual stimuli and less approach to conspecifics compared with controls. In a sub-chronic dosing paradigm during development, methylphenidate caused less robust exploration of a novel tank. In the predator avoidance paradigm, sub-chronic dosing that began at an older age (28 dpf) decreased activity levels more than sub-chronic dosing that began at earlier ages (14 dpf and 21 dpf). In the social shoaling task, sub-chronic methylphenidate attenuated reaction to the social stimulus. Acute and developmental methylphenidate exposure decreased response to environmental cues. Additional research is needed to determine critical mechanisms for these effects and to see how these results may be translatable to neurobehavioral toxicity of prescribing Ritalin® to children and adolescents.
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    Injection drug use among stimulant users in a national sample.
    (The American journal of drug and alcohol abuse, 2004-01) Wu, Li-Tzy; Pilowsky, Daniel J; Wechsberg, Wendee M; Schlenger, William E
    OBJECTIVE:This study examined the correlates of injection drug use (IDU) in a community sample of psychostimulant users. Factors related to the cessation of illicit drug use and substance abuse service utilization were also determined among a subsample of stimulant users who reported IDU. METHOD:The study sample consisted of 3408 lifetime psychostimulant users from the National Household Survey on Drug Abuse. Logistic regression procedures were used to estimate independent associations of correlates of IDU. RESULTS:Approximately one in seven lifetime stimulant users reported IDU in their lifetime. Stimulant users with a lifetime history of IDU were more likely than those who did not inject to be African-American, not have received a high school diploma, have a history of multiple drug use, and report an onset of stimulant use before age 18. Among recent stimulant users, being aged 26 or older, using stimulants at least weekly, and getting drunk in the past year were associated with increased odds of recent IDU. Only one-half of all injection drug users reported having ever used substance abuse services. Cessation of illicit drug use among injectors with a history of stimulant use is common (44%). CONCLUSIONS:Further studies should clarify the natural history of IDU among stimulant users, including the cessation of drug use without participating in substance abuse treatment services.
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    Misuse of methamphetamine and prescription stimulants among youths and young adults in the community.
    (Drug and alcohol dependence, 2007-07) Wu, Li-Tzy; Pilowsky, Daniel J; Schlenger, William E; Galvin, Deborah M
    Gender differences in the prevalence and characteristics of misuse of methamphetamine (meth) and prescription stimulants were examined in a representative US sample of youths and young adults aged 16-25 (N=24,409).Stimulant misusers were categorized into three mutually exclusive subgroups: meth users only, meth and prescription stimulant users, and prescription stimulant users only (e.g., Benzedrine, Ritalin, or Dexedrine). Multinominal logistic regression analyses identified the characteristics associated with misuse of meth and prescription stimulants.About 1 in 10 youths reported any misuse of stimulants in their lifetime. Prescription stimulant misuse occurred earlier and was more frequent than meth misuse. About 47% of meth misusers also reported prescription stimulant misuse. Among misusers of meth and prescription stimulants, males were more likely than females to misuse methylphenidate (82% versus 65%) but were less likely to misuse diet pills or amphetamines (37% versus 49%). Multinominal logistic regression analyses indicated that all subgroups of lifetime stimulant misuse were associated with past year substance abuse. The characteristics of meth misusers differed slightly from prescription stimulants misusers.Multidrug use is common among stimulant misusers. Parents should be informed about the risk of prescription stimulant misuse by their youths.
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    Psychostimulant dependence in a community sample.
    (Substance use & misuse, 2003-01) Wu, Li-Tzy; Schlenger, William E
    OBJECTIVE:To examine the prevalence of psychostimulant dependence and the characteristics associated with nonmedical users' development of dependence. METHODS:The study sample was drawn from the 1995 to 1998 National Household Surveys on Drug Abuse. Statistical analysis was conducted on a total of 1047 individuals aged 12 or older who reported nonmedical use of stimulants in the past year. Multiple multinomial logistic regression identified factors related to stimulant dependence and dependence problems. RESULTS:Among all past year stimulant users, 19% met criteria for stimulant dependence in the past year, and an additional 16% reported having one to two dependence problems. Adjusting for demographics and drug use characteristics, female stimulant users were an estimated 2.6 times more likely than male users to develop dependence. Not only did the Western region of the United States have more recent stimulant users than other regions, its users also were more likely to meet criteria for dependence or experience dependence problems. Stimulant users who had increased odds of progressing into dependence were characterized by an early onset of stimulant use, coexisting multiple illicit drug use, and an onset of daily cigarette smoking between the ages of 13 and 17 years. CONCLUSIONS:Gender differences in initial stimulant use and progression to dependence require further investigation, including contextual, cultural, or perceptual factors related specifically to the choice of drugs by females.
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    Tobacco smoking and other suspected antecedents of nonmedical psychostimulant use in the United States, 1995.
    (Substance use & misuse, 1999-07) Wu, LT; Anthony, JC
    This study investigates the extent to which tobacco smoking is associated with the nonmedical use of psychostimulants and the temporal order of the age of first use for tobacco and psychostimulants within a nationally representative sample of United States household residents. At the same time, alcohol use and other suspected determinants of psychostimulant use are investigated and held constant, using multiple regression models. Data were taken from public use files of the 1995 National Household Survey on Drug Abuse. Conditional logistic regression analyses were performed to derive estimated relative odds of using stimulants for tobacco smokers versus nonsmokers, holding constant other potentially distorting influences. This study provides recent evidence on tobacco smoking as one of the potentially malleable risk factors for the nonmedical use of stimulant drugs.