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1.
In determining the effects of regular marihuana use on neurocognition, abilities within specific relevant cognitive domains prior to regular drug use have not been available. The present study examined effects of current and past regular use of marihuana in subjects for whom pre-drug performance had been ascertained in a prospective, longitudinal fashion. A total of 113 young adults, assessed since infancy, were evaluated using neurocognitive tests for which commensurate measures were obtained prior to the initiation of marihuana smoking. Marihuana users, determined by urinalysis and self-report, were categorized as light (< 5 joints per week) and heavy (> or = 5 joints per week) current users and former users, the latter having used the drug regularly in the past (> or = 1 joint per week) but not for at least 3 months. A third of the subjects were using marihuana on a regular basis at the time of assessment with half being heavy users. Among former, regular users, approximately half had been smoking 5 or more joints per week. Overall IQ, memory, processing speed, vocabulary, attention, and abstract reasoning were assessed. After accounting for potentially confounding factors and pre-drug performance in the appropriate cognitive domain, current regular heavy users did significantly worse than non-users in overall IQ, processing speed, immediate, and delayed memory. In contrast, the former marihuana smokers did not show any cognitive impairments. It was concluded that residual marihuana effects are evident beyond the acute intoxication period in current heavy users after taking into account pre-drug performance but similar deficits are no longer apparent 3 months after cessation of regular use, even among former heavy using young adults.  相似文献   

2.
Since nicotine has been shown to facilitate sustained attention and control of impulsivity, impairment in these domains may influence individuals who initiate smoking for various reasons to continue to smoke cigarettes. The purpose of this study was to determine whether young women who smoke regularly but are not abstinent at the time of testing, differ in their cognitive functioning from non-smokers and whether they resemble women who smoked in the past but quit. Female undergraduate students aged 20-30 years were recruited by advertisement from institutes of higher education in the Jerusalem area. The study sample consisted of 91 current smokers (CS), 40 past smokers (PS) and 151 non-smokers (NS). 46 occasional smokers (OS) were also tested. Confounding by withdrawal state was neutralized by including only CS and OS who smoked their last cigarette less than 90 min before testing. Subjects performed a computerized neurocognitive battery, which tests the domains of attention, memory, impulsivity, planning, information processing and motor performance. Analyses were controlled for age. The results showed that CS made significantly more errors than NS on the Continuous Performance Task (CPT), Matching Familiar Figures Test (MFFT) and Tower of London (TOL) test. PS were significantly worse than NS on the MFFT and TOL test. PS did not differ significantly from CS on any test. No association was found between duration of smoking and performance. These findings suggest that a neurocognitive profile characterized by impairments in sustained attention and control of impulsivity may be one of the factors that predispose young women who initiate cigarette smoking to maintain the habit.  相似文献   

3.
RATIONALE: Prepulse inhibition of the acoustic startle response (PPI) is a paradigm in which a startle response to an auditory stimulus is reduced when that stimulus is preceded by a lower intensity, non-startling stimulus (prepulse). PPI is used as an operational measure of sensorimotor gating in both humans and other mammals. Acute administration of nicotine enhances PPI in rats, an effect that has been recently demonstrated in humans. OBJECTIVES: We compared PPI in 12 male smokers and 14 male non-smokers tested in four repeat startle sessions across 2 test days in order to examine further the effects of smoking and smoking withdrawal on acoustic startle and PPI. METHODS: In a crossover design, the smokers smoked ad lib or abstained from smoking overnight prior to 9 a.m. testing. These 2 test days were in randomized order. On both days, smokers were immediately retested after smoking three cigarettes. Non-smokers were tested twice on each of 2 separate days. RESULTS: Across sessions, the smokers had reduced startle to pulse alone stimuli in the first block of each session when compared to the non-smokers. The non-smokers had no change in gating across their four test sessions. For the smokers, the abstinence condition produced a non-significant reduction in PPI compared to that of the ad lib smoking day. During the smoking abstinence session, smokers had comparable gating to non-smokers. Smoking immediately after washout produced a significant improvement in PPI such that gating in the smokers exceeded that of the non-smokers. CONCLUSION: Smoking after overnight washout from cigarettes enhanced sensorimotor gating compared to pre-smoking values and compared to gating in non-smokers.  相似文献   

4.
A second survey of New Zealand doctors' smoking habits in 1972 elicited an 83 percent response from 3113 doctors. 38.5 percent had never smoked compared with 23.8 percent in a 1963 survey; 29.2 had given up smoking, and 33.3 percent still smoked. Only 21.3 percent smoked cigarettes compared with 35.3 percent in 1963. There has been a sustantial increase in non-smokers among recent graduates. Both sexes now smoke cigarettes less frequently but pipe and cigar smoking by male doctors has risen sharply. Obstetricians smoke cigarettes more often than other groups of doctors, while pathologists, medical administrators and academics smoke the least. Giving up smoking was not difficult for most former smokers except for the heavy smokers who now make up most of the persistent smoker group.  相似文献   

5.
In addition to the health hazards posed individually by cigarette smoking and obesity, the combination of these conditions poses a particular impairment to health. Genetic factors have been shown to influence both traits and, to understand the connection between these conditions, we examined both the observed and genetic relationship between adiposity (an electrical impedance measure of body mass index (BMI)) and cigarettes smoked per day (CPD) in a large sample of current, former, and never smokers in the United Kingdom. In former smokers, BMI was positively associated with cigarettes formerly smoked; further, the genetic factors related to a greater number of cigarettes smoked were also responsible for a higher BMI. In current smokers, there was a positive association between BMI and number of cigarettes smoked, though this relationship did not appear to be influenced by similar genetic factors. We found a positive genetic relationship between smoking in current/former smokers and BMI in never smokers (who would be unmarred by the effects of nicotine). In addition to CPD, in current smokers, we looked at two variables, time from waking to first cigarette and difficulty not smoking for a day, that may align better with cigarette and food ‘craving.’ However, these smoking measures provided mixed findings with respect to their relationship with BMI. Overall, the positive relationships between the genetic factors that influence CPD in smokers and the genetic factors that influence BMI in former and never smokers point to common biological influences behind smoking and obesity.  相似文献   

6.
1. Aggregation of diluted whole blood (impedance method) and thromboxane B2 production during aggregation were measured in cigarette smokers and non-smokers, aged 41-68 years, with (n = 14) and without (n = 15) major symptomatic peripheral vascular disease. The plasma level of the lyso derivative of platelet activating factor (lyso-PAF) was also measured using a bioassay with 14C-serotonin labelled rabbit platelets, after extraction and acetylation to active PAF. 2. Aggregation to ADP and collagen was significantly less in non-smokers without vascular disease (n = 8) than in the other three groups (P less than 0.01; ANOVA). Thromboxane B2 production was not significantly different between the groups. There was no significant difference in plasma lyso-PAF between groups. No change was found in any variable after smokers smoked two cigarettes. 3. In these older age subjects, both vascular disease and the smoking habit were associated with greater whole blood aggregation. However, current smoking and the smoking of two cigarettes did not affect aggregation in subjects with vascular disease and plasma lyso-PAF levels were not consistently related to either smoking or vascular disease.  相似文献   

7.
BACKGROUND: Cigarette smoking is associated with a more severe course of Crohn's disease, but individual factors determining this effect are poorly known and it is not clear whether smoking cessation is associated with an improvement in the disease activity. AIM: To assess the factors determining the harmful effect of smoking in individuals with Crohn's disease. METHODS: A total of 622 consecutive patients with Crohn's disease and Crohn's disease activity index <200 were enrolled in a prospective 12-18 month cohort study. Patients were classified as current smokers, former smokers, or non-smokers. Alcohol consumption, oral contraceptive use, body mass index, and blood lipid levels were also recorded. The main outcome measure was the rate of flare-up. RESULTS: A total of 139 current smokers (46%) developed a flare-up, vs. 79 non-smokers (30%) and 13 former smokers (23%). The relative risk of flare-up adjusted for confounding factors was 1.35 (1.03-1.76) in current smokers. This risk was increased in patients with previously inactive disease and in those who had no colonic lesions. It became significant above a threshold of 15 cigarettes per day. Former smokers behaved like non-smokers. Obesity, dyslipidaemia, and alcohol consumption had no significant effect. CONCLUSIONS: Current smoking, particularly heavy smoking, markedly increases the risk of flare-up in Crohn's disease. Former smokers have a risk similar to that of non-smokers.  相似文献   

8.
The impact of active and passive smoking on the serum levels of alpha 1-AT, the trypsin inhibitory capacity (TIC), the trypsin inhibitory activity (TIA) and the urinary hydroxyproline to creatinine ratio (HOP-ratio) was studied. The subjects used in the study on active smoking were 167 healthy adult men and in the study on passive smoking 189 healthy primary school children. Serum levels of alpha 1-AT in active smokers were significantly higher than those in non-smokers. The TIC as well as the TIA in active smokers decreased with increasing number of cigarettes smoked. The urinary HOP-ratio increased significantly with increasing number of cigarettes smoked. On the other hand, in the case of passive smokers a significant difference was obtained only for the HOP-ratio. The correlations between all markers in active smokers were significant. Less significant correlations were found in the case of passive smokers. These results suggest that the urinary excretion of hydroxyproline can be considered as a marker for the imbalance between proteases and anti-proteases as a result of smoking.  相似文献   

9.

Background

Little is known about time-varying effects of smoking quantity and nicotine dependence on the regularity of adolescent smoking behavior.

Methods

The sample was drawn from the Social and Emotional Contexts of Adolescent Smoking Patterns Study which followed adolescent smokers over 5 assessment waves spanning 48 months. Participants included former experimenters (smoked <100 cigarettes/lifetime but did not smoke in past 90 days), recent experimenters (smoked <100 cigarettes/lifetime and smoked in past 90 days), and current smokers (smoked >100 cigarettes/lifetime and smoked in past 30 days). Mixed-effects regression models were run to examine the time-varying effects of smoking quantity and nicotine dependence on regularity of smoking behavior, as measured by number of days smoked.

Results

Smoking quantity and nicotine dependence were each found to be significantly associated with regularity of adolescent smoking and the size of each effect exhibited significant variation over time. The effect of smoking quantity decreased across time for each smoking group, while the effect of nicotine dependence increased across time for former and recent experimenters. By the 48-month follow-up, the effects of smoking quantity and nicotine dependence had each stabilized across groups.

Conclusions

This study reveals that smoking quantity and nicotine dependence are not static risk factors for the development of more regular smoking patterns. At low levels of smoking when nicotine dependence symptoms are less common, smoking quantity is a stronger predictor of increased regularity of smoking, while for more experienced smokers, nicotine dependence predicts further increases in regularity.  相似文献   

10.
The present study examined the situation-specific effects of smoking using a paced regimen of smoking to control the smoke intake. The subjects were first required to sham smoke and then actually smoke one of their cigarettes in two different test contexts: 1) in the laboratory where they had never previously smoked and 2) at home, alone in a quiet room where they regularly smoke. Light (< 10 cigarettes/day) and heavy smokers (> 15 cigarettes/day) were studied to test for a possible effect of the paced regimen itself. In the light smokers, smoking produced a larger increase in heart rate (HR) in the laboratory than in the natural smoking environment; however, in the heavy smokers the smoking had a larger effect in the normal smoking environment than in the laboratory. There were no significant group or test situation differences for baseline HR, skin conductance and finger temperature. The groups also did not differ in the intensity of drawing on the cigarette or inhaling, as indicated by a puff sensor and a respiratory belt, respectively. It was concluded that differences between the effects of a cigarette in a laboratory setting and in a natural smoking environment may reflect pharmacodynamic effects of smoking that are modified by the subjects' prior experience with smoking. The data are discussed with regard to conditioned tolerance to the effect of smoking.  相似文献   

11.
The present study examined the situation-specific effects of smoking using a paced regimen of smoking to control the smoke intake. The subjects were first required to sham smoke and then actually smoke one of their cigarettes in two different test contexts: 1) in the laboratory where they had never previously smoked and 2) at home, alone in a quiet room where they regularly smoke. Light (<10 cigarettes/day) and heavy smokers (> 15 cigarettes/day) were studied to test for a possible effect of the paced regimen itself. In the light smokers, smoking produced a larger increase in heart rate (HR) in the laboratory than in the natural smoking environment; however, in the heavy smokers the smoking had a larger effect in the normal smoking environment than in the laboratory. There were no significant group or test situation differences for baseline HR, skin conductance and finger temperature. The groups also did not differ in the intensity of drawing on the cigarette or inhaling, as indicated by a puff sensor and a respiratory belt, respectively. It was concluded that differences between the effects of a cigarette in a laboratory setting and in a natural smoking environment may reflect pharmacodynamic effects of smoking that are modified by the subjects’ prior experience with smoking. The data are discussed with regard to conditioned tolerance to the effect of smoking.  相似文献   

12.
《Substance use & misuse》2013,48(8):719-725
The relationships between the number of cigarettes smoked/day and the number of puffs/cigarette, puff duration, and total puff time/cigarette were studied. Data were collected on 12 regular smokers for all cigarettes smoked over a 3-day period in a nonlaboratory environment. Between-subject variability was substantial on each of the topographical measures. Neither the number of cigarettes smoked per day nor the classification of Heavy (> 25 cigarettes/day) vs Moderate (< 25 cigarettes/day) smoking levels was related to the intensity with which cigarettes were smoked. Within-subject consistency on the topography measures indicates that smokers may have relatively unique smoking patterns.

Most studies of smoking in the natural environment employ number of cigarettes/day as their estimate of smoke exposure. However, total smoke exposure is determined by an interaction of various topographical features, including frequency (number of cigarettes/day, number of puffs/cigarette), durational (puff duration, interpuff interval, intercigarette interval), and volumetric (puff volume, inhalation volume) components. Employing cigarettes/day to estimate smoke exposure assumes a consistent relationship between cigarettes/day and other topographical features which contribute to total smoke exposure, but it is not clear that such a relationship exists. Laboratory studies of smoking behavior have found that cigarette frequency may vary independently of these other topographic components of smoking, lichtenstein and Antonuccio (1981) examined smoking topography in 24 male smokers while they smoked a cigarette during two 45-minute sessions. They found that cigarette rate was significantly related to intercigarette interval, but not to puff frequency, puff duration, cigarette duration, and amount of tobacco burned.

Results found in laboratory settings, however, have been found not to necessarily generalize to nonlaboratory environments. For example, OssipKlein, Martin, Lomax, Prue, and Davis (1983) examined six subjects smoking adlib in three settings: natural, clinical, and laboratory. They found that cigarette durations were shorter and that subjects took significantly longer and more puffs in a clinical or laboratory setting compared to a naturalistic setting. Thus, examination of the relationship between topographical features in naturalistic smoking would appear to require direct study outside the laboratory.

The present study is to our knowledge the first to examine topographical features of smoking and the relationship between number of cigarettes smoked/ day and other measures of smoking topography while the subject smoked ad-lib in a nonlaboratory environment. This information would potentially be important in examining the extent of individual differences in smoking topography, in assessing the extent to which cigarettes/day is related to other aspects of smoking behavior, and in determining whether categorizing smokers into smoking groups (e.g., moderate and heavy) on the basis of number of cigarettes/day accurately reflects the amount of total smoke exposure/day.  相似文献   

13.
Reduced 5-HT1A-receptor responsiveness has been reported in patients with panic disorder(PD) and/or agoraphobia (PDA). Although many of these patients are regular smokers, it has not been examined whether psychological or neurobiological effects induced by the selective 5-HT1A-receptor agonist, ipsapirone, are affected by the smoking status of the patients.In order to clarify this question neuroendocrine challenges with oral doses of ipsapirone (0.3 mg/kg) and placebo were performed in 39 patients with PDA, and results were compared between patients who smoked (>10 cigarettes per day, n = 17) and patients who had been non-smokers for at least two years (n = 22).Patients who were smokers (but did not smoke during the challenge procedure) had significantly reduced baseline concentrations of cortisol and a significantly lower body temperature. In comparison to placebo, administration of ipsapirone was associated with significant increases of various psychological symptoms and plasma cortisol concentrations. The subgroup of PD patients who were smokers showed significantly higher cortisol responses to ipsapirone than non-smokers.In conclusion, smoking status has to be taken into account when assessing the responsiveness of 5-HT1A receptors in patients with psychiatric disorders. The prevention of smoking during challenge sessions might not be the ideal approach in heavy smokers, since sudden abstinence from smoking is likely to affect neurobiological and possibly psychological responses to ipsapirone.  相似文献   

14.
This study was undertaken to examine the relationship between cigarette-smoking and total white blood cell count (wbcc) and platelet count (pc) in adult Nigerians. We also studied the relationship of the white blood cell and platelet counts to the duration of the smoking habit and number of cigarette smoked per day. Three hundred and fifty-two healthy male adults, aged 18-52 years, were studied. They were randomly allocated to two groups--176 smokers and 176 non-smokers. The smoking habit was assessed from a minimum period of 1 year and a minimum number of 5 cigarettes per day. Results revealed that platelet count was higher for the regular Nigerian smoker than for non-smoker. The difference between mean platelet counts for smokers and non-smokers was statistically significant (t = 2.64 p = 0.0046). Man WBC count in smokers was slightly higher than for non-smokers. However, unlike in the case of platelet counts, the mean difference in WBC count between smokers and non-smokers is not statistically significant (t = 0.07, p value = 0.9442). Similar studies based on white population has showed statistically significant increases in wbcc and pc in smokers.  相似文献   

15.
This study examined the effects of acute doses of ethanol on smoking in cigarette smokers. Subjects were moderate to-heavy smokers (20-30 cigarettes/day) who drank alcohol regularly (4-10 drinks/week). Using a within-subjects design, the dose of ethanol ingested was varied and the number of cigarettes smoked and the temporal pattern of smoking were evaluated. At the beginning of the session, subjects ingested placebo, 0.2, 0.4, or 0.8g/kg ethanol and were then allowed to smoke freely for 3h. Subjective mood measures, physiological measures and psychomotor performance were examined at hourly intervals. Subjects smoked more cigarettes during the first hour post-beverage after consuming 0.4 or 0.8g/kg ethanol than after consuming placebo or 0.2g/kg ethanol. During the second and third hours of smoking, no differences were observed between the conditions. Changes in the carbon monoxide content of subjects' breath as a function of dose were not significant, but were in the expected direction based on the number of cigarettes smoked under the different conditions. We conclude that alcohol increases cigarette consumption in non-alcohol-abusing smokers, but that this effect is short-lived and occurs only during the ascending limb of the blood alcohol curve.  相似文献   

16.
The use of retrospective data in smoking research represents possible sources of bias resulting from: (1) baseline incomparability of current, former, and non-smokers, (2) instability of parameters under investigation, and (3) difficulties in recall. A self-report measure of smoking motives was employed in a longitudinal design to examine bias associated with retrospective data analysis. Thirty-six pairs of former smokers and recidivists (smokers who had tried to quit) were matched on age and amount smoked. Although initial responses for both groups were comparable, former smokers were significantly higher on smoking motive factors after quitting compared to recidivists who stayed essentially the same. The findings suggest that mean differences in smoking motives between recidivists and former smokers assessed cross-sectionally may not accurately reflect the magnitude of the differences that existed when both groups were smoking.  相似文献   

17.
This study examined smoking trajectories between adolescence and adulthood in an African American cohort followed prospectively from first grade to age 32. We classified non-smokers, former smokers, current smokers/late adopters (initiated after age 18), and current smokers/early adopters (initiated before age 17). Results show that almost half of the population were currently smoking. Multiple logistic regression analyses showed that non-smokers differed most from the three smoking groups on social integration. Non-smokers were less likely to have left home before the age of 18, to have had more drug use parental supervision as an adolescent, to have moved less, and to attend church more frequently as an adult. Those current smokers who initiated early differed from the non-smokers and also from the former smokers and the current smokers who adopted smoking after the age of 18; they were more likely to be rated as aggressive or both shy and aggressive by their first grade teachers and to have drug problems as adults. Current smokers were less likely to attend church as adults than the non-smokers and former smokers. Neither mother's smoking or lifetime depression was related to smoking. The findings elucidate the contribution of factors over the life course that have an impact on smoking initiation, continuation, and cessation. They highlight the importance of targeting African American children and adolescents for prevention despite the fact that African American youth have the lowest rates of smoking across all ethnic groups. Possible interventions could be aimed at early aggressive behavior, parental supervision and monitoring, and other social integration efforts.  相似文献   

18.
Heavy use of marijuana is claimed to damage critical skills related to short-term memory, visual scanning and attention. Motor skills and driving safety may be compromised by the acute effects of marijuana. The aim of this study was to investigate the acute effects of 13 mg and 17 mg Delta 9-tetrahydrocannabinol (THC) on skills important for coordinated movement and driving and on subjective and autonomic measures in regular users of marijuana. Fourteen regular users of marijuana were enrolled. Each subject was tested on two separate days. On each test day, subjects smoked two low-nicotine cigarettes, one with and the other without THC. Seventeen mg THC was included in the cigarette on one test day and 13 mg on the other day. The sequence of cigarette types was unknown to the subject. During smoking, heart rate and blood pressure were monitored, and the subjects performed a virtual reality maze task requiring attention and motor coordination, followed by 3 other cognitive tasks (Wisconsin Card Sorting Test (WCST), a "gambling" task and estimation of time and distance from an approaching car). After smoking a cigarette with 17 mg THC, regular marijuana users hit the walls more often on the virtual maze task than after smoking cigarettes without THC; this effect was not seen in patients after they smoked cigarettes with 13 mg THC. Performance in the WCST was affected with 17 mg THC and to a lesser extent with the use of 13 mg THC. Decision making in the gambling task was affected after smoking cigarettes with 17 mg THC, but not with 13 m THC. Smoking cigarettes with 13 and 17 mg THC increased subjective ratings of pleasure and satisfaction, drug "effect" and drug "high". These findings imply that smoking of 17 mg THC results in impairment of cognitive-motor skills that could be important for coordinated movement and driving, whereas the lower dose of 13 mg THC appears to cause less impairment of such skills in regular users of marijuana.  相似文献   

19.
Data from the Tucson epidemiological study of airways obstructive disease on smoking of non-tobacco cigarettes such as marijuana were analysed to determine the effect of such smoking on respiratory symptoms and pulmonary function. Among adults aged under 40, 14% had smoked non-tobacco cigarettes at some time and 9% were current users. The prevalence of respiratory symptoms was increased in smokers of non-tobacco cigarettes. After tobacco smoking had been controlled for men who smoked non-tobacco cigarettes showed significant decreases in expiratory flow rates at low lung volumes and in the ratio of the forced expiratory volume in one second to the vital capacity. This effect on pulmonary function in male non-tobacco cigarette smokers was greater than the effect of tobacco cigarette smoking. These data suggest that non-tobacco cigarette smoking may be an important risk factor in young adults with respiratory symptoms or evidence of airways obstruction.  相似文献   

20.
Cigarette smoking increased during alcohol self-administration in comparison to an alcohol-free baseline in 24 women given access to alcohol for 21 days. Heavy smokers (25 or more cigarettes per day) increased smoking significantly during drinking (P<0.05). Analysis of tobacco smoking by level of alcohol consumption showed that both heavy and moderate alcohol users increased smoking significantly during alcohol availability (P<0.05, 0.01). The heavy and moderate smokers smoked significantly more between noon and midnight (P<0.001) than at other times when alcohol was available. The rate of cigarette smoking (defined by inter-cigarette intervals) was faster during alcohol self-administration than during the alcohol-free baseline. Heavy smokers smoked most cigarettes at intervals of 11–20 min during heavy or moderate drinking. During the pre-alcohol baseline, these women smoked most cigarettes at intervals of 21–30 or 31–40 min. Most women (70–74%) also increased tobacco smoking at the premenstruum. Both heavy and occasional smokers increased smoking at the premenstruum significantly more than the moderate smokers (P<0.05). All women reported increased psychological discomfort at the premenstruum on the Premenstrual Assessment Form (PAF) but reports of physical discomfort were more marked in women who smoked less at the premenstruum. These data extend previous findings in men that alcohol consumption is associated with increased cigarette smoking to female social drinkers.  相似文献   

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