RESUMO
BACKGROUND: Light and moderate drinkers respond differently to the effects of abused drugs, including stimulants such as amphetamine. The purpose of this study was to determine whether light and moderate drinkers differ in their sensitivity to the reinforcing and subjective effects of d-amphetamine. We hypothesized that moderate drinkers (i.e., participants that reported consuming at least seven alcohol-containing beverages per week) would be more sensitive to the reinforcing and positive subject-rated effects of d-amphetamine than light drinkers. METHODS: Data from four studies that employed similar d-amphetamine self-administration procedures and subject-rated drug-effect measures were included in the analysis. Light (n = 17) and moderate (n = 16) drinkers sampled placebo, low (8 to 10 mg), and high (16 to 20 mg) doses of oral d-amphetamine administered in eight capsules. Following sampling sessions, participants worked for a maximum of eight capsules, each containing 12.5% of the previously sampled dose, on a modified progressive-ratio schedule of reinforcement. RESULTS: Both active doses of d-amphetamine functioned as a reinforcer in the moderate drinkers, while only the high dose did so in the light drinkers. The moderate drinkers worked for significantly more capsules that contained the high dose of d-amphetamine than did the light drinkers. d-Amphetamine produced prototypical stimulant-like subjective effects (e.g., dose-dependent increases in ratings of Good Effects; Like Drug and Willing to Take Again). Moderate drinkers reported significantly greater subjective effects than the light drinkers. CONCLUSION: These results are consistent with those from previous laboratory experiments and suggest that moderate alcohol consumption may increase vulnerability to the abuse-related effects of stimulants.
Assuntos
Consumo de Bebidas Alcoólicas/psicologia , Anfetamina/administração & dosagem , Comportamento Aditivo/psicologia , Esquema de Reforço , Adolescente , Adulto , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Autoadministração , Inquéritos e Questionários , Adulto JovemRESUMO
INTRODUCTION: Stimulants increase cigarette smoking in the naturalistic environment and laboratory. The effects of methylphenidate on a 9-trial, discrete cigarette versus money ($0.25) choice task were tested to elucidate the mechanisms underlying stimulant-induced increases in smoking. METHODS: Eleven participants who reported smoking 10-20 cigarettes/day completed the study. Four doses of methylphenidate (0, 10, 20, and 40 mg) were administered across 5 experimental sessions, with placebo administered twice. One hour following medication administration and at 30-min intervals thereafter, participants chose between smoking a cigarette and receiving US$0.25. The primary behavioral outcome measure was number of cigarette choices. RESULTS: Methylphenidate increased the number of cigarette choices over money. Puffs per session and carbon monoxide levels increased significantly and caloric intake decreased significantly following methylphenidate administration relative to placebo. CONCLUSIONS: The results of this study suggest that methylphenidate increases the relative reinforcing efficacy of cigarette smoking. Stimulant use may thus be an important consideration for individuals attempting to quit smoking.
Assuntos
Estimulantes do Sistema Nervoso Central/farmacologia , Comportamento de Escolha/efeitos dos fármacos , Metilfenidato/farmacologia , Fumar , Adulto , Monóxido de Carbono/sangue , Ingestão de Energia/efeitos dos fármacos , Feminino , Humanos , Masculino , Placebos , Adulto JovemRESUMO
Adverse childhood experiences (ACEs) are associated with persistent physical and psychological impairments over time and intergenerational transmission of trauma. Few studies have examined contexts of acute adversity with an eye toward understanding intergenerational transmission of ACEs. Homelessness and residential mobility are strongly associated with increased deficits across key developmental domains throughout the lifespan. This study (N = 86 parent-child dyads living in emergency housing) examined the effect of parent ACEs under the age of 18 years on parent and child lifetime adverse experiences. Results demonstrated significant relationships between parent ACEs and parent adversity over 18 years of age, child lifetime adversity, and current child trauma symptomatology. These findings highlight the impact of parent early experiences on off spring and underscore the importance of understanding the impact of and intervening to end the intergenerational transmission of trauma in acute adversity. Implications of these findings, including intervention, policy, and practice, are discussed.
Assuntos
Experiências Adversas da Infância , Pessoas Mal Alojadas , Adolescente , Adulto , Família , Humanos , Pais , Problemas SociaisRESUMO
At a proximal level, the physiological impacts of global climate change on ectothermic organisms are manifest as changes in body temperatures. Especially for plants and animals exposed to direct solar radiation, body temperatures can be substantially different from air temperatures. We deployed biomimetic sensors that approximate the thermal characteristics of intertidal mussels at 71 sites worldwide, from 1998-present. Loggers recorded temperatures at 10-30 min intervals nearly continuously at multiple intertidal elevations. Comparisons against direct measurements of mussel tissue temperature indicated errors of ~2.0-2.5 °C, during daily fluctuations that often exceeded 15°-20 °C. Geographic patterns in thermal stress based on biomimetic logger measurements were generally far more complex than anticipated based only on 'habitat-level' measurements of air or sea surface temperature. This unique data set provides an opportunity to link physiological measurements with spatially- and temporally-explicit field observations of body temperature.
Assuntos
Bivalves/fisiologia , Temperatura Corporal , Animais , Mudança Climática , EcossistemaRESUMO
The availability of alternative reinforcers reduces drug taking. Escalating alternative reinforcer values have been used to initiate and maintain abstinence from drug use. A reset in reinforcer value has been added to the schedule of alternative reinforcer presentation to discourage relapse. The purpose of this preliminary study was to test the influence of escalating and escalating and resetting alternative reinforcer value on cigarette choice in the human laboratory. Fourteen daily cigarette smokers completed this experiment, which required one practice and three experimental sessions. During each experimental session, subjects made six choices between smoking a cigarette and receiving money, available under Constant, Escalating or Escalating and Resetting conditions. The total number of cigarettes chosen and puffs taken, but not the maximum consecutive number of cigarettes choices, was decreased in the Escalating condition relative to the Constant condition. The maximum number of consecutive cigarettes chosen was decreased in the Escalating and Resetting condition relative to the Constant condition. The proportion of money earned was increased in the Escalating condition relative to the Constant and Escalating and Resetting conditions. These initial findings indicate that whereas an escalating alternative reinforcer schedule reduces cigarette smoking overall, an escalating and resetting alternative reinforcer schedule may reduce repeated cigarette smoking (i.e., relapse).
Assuntos
Comportamento de Escolha , Reforço Psicológico , Fumar , Adulto , Feminino , Humanos , Masculino , Prevenção Secundária , Adulto JovemRESUMO
RATIONALE: Methylphenidate (Ritalin®) is commonly prescribed for behavioral problems associated with attention deficit/hyperactivity disorder (ADHD). The results of previous studies suggest that methylphenidate increases cigarette smoking in participants without psychiatric diagnoses. Whether methylphenidate increases cigarette smoking in participants diagnosed with ADHD is unknown. OBJECTIVE: In this within-subjects, repeated measures experiment, the acute effects of a range of doses of methylphenidate (10, 20, and 40 mg) and placebo were assessed in nine cigarette smokers who were not attempting to quit and met diagnostic criteria for ADHD but no other Axis I psychiatric disorders other than nicotine dependence. METHODS: Each dose of methylphenidate was tested once while placebo was tested twice. One hour after ingesting drug, participants were allowed to smoke ad libitum for 4 h. Measures of smoking included total cigarettes smoked, total puffs, and carbon monoxide levels. Snacks and decaffeinated drinks were available ad libitum; caloric intake during the 4-h smoking session was calculated. RESULTS: Methylphenidate increased the total number of cigarettes smoked, total number of puffs, and carbon monoxide levels. Methylphenidate decreased the number of food items consumed and caloric intake. CONCLUSIONS: The results of this experiment suggest that acutely administered methylphenidate increases cigarette smoking in participants with ADHD, which is concordant with findings from previous studies that tested healthy young adults. These data indicate that clinicians may need to consider non-stimulant options or counsel their patients before starting methylphenidate when managing ADHD-diagnosed individuals who smoke.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Estimulantes do Sistema Nervoso Central/farmacologia , Metilfenidato/farmacologia , Fumar/epidemiologia , Adulto , Monóxido de Carbono/análise , Estimulantes do Sistema Nervoso Central/administração & dosagem , Relação Dose-Resposta a Droga , Método Duplo-Cego , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Energia/efeitos dos fármacos , Feminino , Humanos , Masculino , Metilfenidato/administração & dosagem , Adulto JovemRESUMO
Rate-of-onset modulates the subject-rated effects of stimulants. Results of two studies from our laboratory demonstrate that immediate-release methylphenidate increases smoking and decreases caloric intake. Whether rate-of-onset influences the effects of methylphenidate on smoking and eating is unknown. The present experiment examined the influence of a range of doses of immediate- (7.5-30 mg) and sustained-release (18-72 mg) methylphenidate as well as placebo on smoking and eating. Eight cigarette smokers participated. A double-dummy drug administration procedure was used to maintain the double blind because immediate-release methylphenidate produces peak plasma concentrations 1.5-2 h and the sustained-release formulation produces peak plasma concentrations 6-8 h after oral administration. Smoking and eating were assessed for 4 h across the predicted peak effects of both methylphenidate formulations. Measures of smoking included total cigarettes, puffs, and carbon monoxide levels. Snacks and decaffeinated beverages were available ad libitum and caloric intake was monitored during the four-hour smoking session. Immediate- and sustained-release methylphenidate increased smoking and decreased caloric intake. The effects of methylphenidate generally did not vary as a function of formulation. The results of this study may have important implications for the treatment of disorders that require stimulant medications. Smoking should be monitored in patients that are prescribed stimulant medications, regardless of the formulation type.