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Biomedical subjects

J M Roll

Publications and source records attributed to J M Roll.

8 recordsLinked to original sources
PubMed1998

Use of monetary reinforcement to reduce the cigarette smoking of persons with schizophrenia: a feasibility study.

The feasibility of using monetary reinforcement to promote abstinence from substance use in adult individuals with schizophrenia was addressed. Cigarette smoking was studied as an exemplar of drug use in 11 individuals with schizophrenia by use of a within-subject experimental design. The study duration was 3 weeks, with weeks 1 and 3 serving as baseline conditions and week 2 serving as the intervention condition; in the latter, patients could earn money by abstaining from cigarette smoking. Abstinence was significantly greater during the intervention condition than during the baseline conditions. These results illustrate the potential sensitivity of drug use in this population to reinforcement contingencies, suggesting that contingency-management interventions are a feasible option for treating the substance abuse of individuals with schizophrenia.

Adult↗
PubMed1997

Cocaine use can increase cigarette smoking: evidence from laboratory and naturalistic settings.

Two studies examined the effects of cocaine use on cigarette smoking. Study 1 was conducted with 10 healthy volunteers under controlled laboratory conditions. Participants received double-blind doses of intranasal cocaine HCl (100 mg) or placebo in separate sessions, with each being followed by a 3-hr period of monitored cigarette smoking. Latency to the first cigarette and the mean interval between cigarettes was significantly shorter and the total number of cigarettes smoked was greater after cocaine than placebo administration. Study 2 was conducted by using urine specimens from 9 ambulatory cocaine-dependent patients. Urine cotinine (nicotine metabolite) levels on days when urinalysis testing indicated recent cocaine use were compared with levels on days when urinalysis testing indicated no recent use. Cotinine levels were significantly higher on cocaine-positive days, indicating that cocaine use was associated with greater cigarette smoking. Overall results provide evidence that acute cocaine administration can increase cigarette smoking.

Adolescent↗
PubMed1996

Alcohol pretreatment increases preference for cocaine over monetary reinforcement.

Non-dependent cocaine users participated in a two-phase experiment conducted under controlled laboratory conditions. During phase 1, subjects sampled intranasal cocaine (100 mg) and placebo (96 mg lactose + 4 mg cocaine) in separate sessions and under double-blind conditions. Sampling sessions were followed by a single choice session in which subjects made a maximum of ten choices between 10 mg unit doses of cocaine or placebo. Only subjects who reliably (> or = 70%) chose cocaine over placebo in phase 1 participated in phase 2. During phase 2, subjects participated in a series of nine experimental sessions conducted on different days in which they were pretreated with varying doses of alcohol (placebo, 0.5, and 1.0 g/kg) and made a maximum of ten choices between 10 mg unit doses of cocaine and an alternative reinforcer (i.e., varying amounts of money). Visual-analog ratings of drug effects and cardiac function were monitored across all experimental sessions. Cocaine was reliably chosen over placebo by the majority (9 of 11) of subjects during phase 1, demonstrating that the drug functioned as a reinforcer. During phase 2, alcohol pretreatment significantly increased choice of cocaine over the alternative reinforcer, while increasing monetary value decreased cocaine choice. Ratings on some visual-analog scales (e.g., good effects) paralleled cocaine choice, with alcohol pretreatment increasing ratings and greater monetary value decreasing them. Cardiac output increased above baseline levels across all alcohol and monetary conditions, but maximal effects were observed during sessions involving pretreatment with the active alcohol doses. Overall, these results demonstrate (a) that alcohol can increase preference for cocaine over alternative reinforcers and thereby may thwart efforts to reduce or abstain from cocaine use, (b) that availability of an alternative, non-drug reinforcer can effectively decrease preference for cocaine, and (c) that combined use of alcohol and cocaine increases cardiac risk compared to use of cocaine alone.

Adult↗
PubMed1996

A comparison of cocaine-dependent cigarette smokers and non-smokers on demographic, drug use and other characteristics.

Cigarette smoking (n = 156) and non-smoking (n = 43) individuals seeking out-patient treatment for cocaine-dependence were compared on demographic, drug use and other variables. Smokers were younger, less educated, earned less money, began cocaine use at an earlier age, used cocaine more frequently, were more likely to inject or smoke cocaine, were more likely to report legal troubles and having harmed someone physically as consequences of their cocaine use, and had more severe employment and legal problems than non-smokers as measured by the Addiction Severity Index. Smoking remained a significant predictor of more frequent cocaine use, using more grams of cocaine per week and using cocaine via an injection or smoking route even after adjusting for demographic differences between smokers and non-smokers via regression analyses. Smoking status was not significantly related to treatment outcome. Overall, these results indicate that cocaine-dependent smokers represent a more high-risk group than non-smokers. This relationship between smoking, cocaine use, and associated problems merits further investigation.

Adult↗
PubMed1996

An experimental comparison of three different schedules of reinforcement of drug abstinence using cigarette smoking as an exemplar.

The efficacy of three different schedules of reinforcement for promoting and sustaining drug abstinence was compared in this study. Cigarette smoking was studied as an exemplar of stimulant drug self-administration. Sixty cigarette smokers were assigned to one of three groups (progressive rate of reinforcement, fixed rate of reinforcement, and yoked control). Participants in all three groups were asked to refrain from smoking for 1 week. Participants in the progressive and fixed groups achieved greater mean levels of abstinence than those in the control group. Participants in the progressive group were significantly less likely to resume smoking when they became abstinent than participants in the other groups.

Adolescent↗
PubMed1995

Tolerance-like attenuation to contingent and noncontingent cocaine-induced elevation of extracellular dopamine in the ventral striatum following 7 days of withdrawal from chronic treatment.

Time-dependent changes in mesolimbic dopamine (DA) function are believed to play a role in behavioral sensitization and drug craving experienced during withdrawal from chronic cocaine administration. The present study utilized intravenous (IV) cocaine self-administration coupled with intracranial microdialysis in rats to investigate time dependent changes during withdrawal from chronic cocaine exposure. Following 2 weeks of IV cocaine self-administration, rats were allowed contingent access to cocaine at 1 and 7 days of withdrawal while extracellular levels of DA were measured from the ventral striatum. A second group of animals received yoked, noncontingent cocaine for 2 weeks and were then administered noncontingent cocaine on days 1 and 7 of withdrawal. In addition, a third group of animals received 2 weeks of yoked saline followed by noncontingent cocaine 1 day after withdrawal. There were no significant differences between groups for the overall cocaine dosage or temporal pattern of infusions on days 1 and 7 of withdrawal. Basal extracellular DA concentrations did not differ between any treatment groups at either withdrawal time. Extracellular DA levels were increased throughout the session on both days; however, the increases at day 7 were significantly less than day 1 for both contingent and noncontingent conditions. DA overflow on day 1 did not differ between animals receiving chronic yoked cocaine or saline. These results suggest that tolerance-like attenuation to the DA-elevating effects of cocaine is not apparent early in withdrawal, but does develop by later time points.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Responding changes systematically within sessions during conditioning procedures.

When the procedure is held constant within an experimental session, responding often changes systematically within that session. Many of these within-session changes in responding cannot be dismissed as learning curves or by-products of satiation. They have been observed in studies of positive reinforcement, avoidance, punishment, extinction, discrimination, delayed matching to sample, concept formation, maze and alley running, and laboratory analogues of foraging, as well as in the unconditioned substrates of conditioned behavior. When aversive stimuli are used, responding usually increases early in the session. When positive reinforcers are used, responding changes in a variety of ways, including increasing, decreasing, and bitonic functions. Both strong and minimal reinforcement procedures produce within-session decreases in positively reinforced behavior. Within-session changes in responding have substantial theoretical and methodological implications for research in conditioning.

Animals↗