Motivational effects of smoked marijuana: behavioral contingencies and low-probability activities.

Six adult male research volunteers, in two groups of 3 subjects each, lived in a residential laboratory for 15 days. All contact with the experimenters was through a networked computer system, and subjects' behavior was monitored continuously and recorded. During the first part of each day, they were allowed to socialize. Two cigarettes containing active marijuana (2.7% delta 9-THC) or placebo were smoked during the private work period and the period of access to social activities. Three-day contingency conditions requiring subjects to engage in a low-probability work activity (instrumental activity) in order to earn time that could be spent engaging in a high-probability work activity (contingent activity) were programmed during periods of placebo and active-marijuana smoking. During placebo administration, the contingency requirement reliably increased the amount of time that subjects spent engaged in the low-probability instrumental activity and decreased the time spent engaged in the high-probability activity. During active-marijuana administration, however, the increases in instrumental activity were consistently larger than observed under placebo conditions. The decreases in contingent activity were similar to those seen under placebo conditions. Smoking active marijuana was thus observed to produce increments in instrumental activity under motivational conditions involving contingencies for "work activities."     

Incremental Validity of Coping-oriented Marijuana Use Motives in the Prediction of Affect-based Psychological Vulnerability

The present investigation examined whether coping-oriented motives to use marijuana, as measured by the Marijuana Motives Measure (MMM; Simons et al. in J. Couns. Psychol. 45:265–273, 1998), were uniquely related to affect-based psychological vulnerability factors among marijuana users. Participants were 131 adult current marijuana users (72 women, M _age = 20.14, SD = 3.37 years). As hypothesized, after controlling for gender, cigarettes smoked per day, past 30-day marijuana use, total years of marijuana use, and alcohol consumption, coping motives were significantly and incrementally related to negative affect-based psychological vulnerability factors. No other marijuana use motives demonstrated a similar type of relationship to the dependent variables, providing a high degree of explanatory specificity. These data suggest that coping-oriented motives to use marijuana may be an important explanatory construct in better understanding marijuana and psychological vulnerability relations.     

Gustatory responses during periods of controlled and ad lib cigarette smoking

Three psychophysical methods, differential sensitivity, perceived intensity, and degree of liking, were used to measure gustatory responses among nonsmokers and among smokers who were placed on 2-week schedules of increased and decreased cigarette consumption. Varying the smoking levels had little influence on the smokers’ sensitivity to the tastes of sucrose and sodium chloride. Throughout the experiments, nonsmokers were slightly more sensitive than smokers. Lower intensity ratings were ascribed to both compounds by smokers than by nonsmokers. Degree of liking of the test solutions was unrelated to smoking. A subsequent experiment showed that 45 nonsmokers were slightly, but not significantly, more sensitive than were 45 smokers to the tastes of sucrose, sodium chloride, citric acid, and quinine hydrochloride, with no differences in their sensitivity to the odor of 2-butanone and to the viscosity imparted by carrageenan gum. There was a slight inverse relationship between sensitivity and the number of cigarettes smoked per day. Smokers liked coffee significantly better and drank more cups per day than did nonsmokers. Few changes in body weight were observed, despite the smokers’ subjective assessment that their appetites and food intake were inversely related to the number of cigarettes smoked.     

Reducing cigarette smoking in a retarded adult: An application of self-management procedures

An attempt was made to reduce the overall number of cigarettes smoked per day with a mildly retarded adult. Self-monitoring was compared to self-monitoring plus self-graphing and goal setting procedures in reducing the number of cigarettes smoked. Self-monitoring plus self-graphing and goal setting was superior to self-monitoring alone when the goal was set at 15 cigarettes per day, but the actual number of cigarettes smoked increased when the goal was set at 12. The number of cigarettes smoked during all treatment conditions was lower than either baseline conditions. The therapist also reduced the patient's caffeine intake and switched the client's brand of cigarettes to a low “tar”/nicotine brand. The reduction in caffeine and “tar”/nicotine was related to a small and transient increase in somatic complaints and verbal abuse, as well as the complete elimination of nocturnal enuresis. Brand switching to low “tar”/nicotine cigarettes did not result in an increase in the number of cigarettes smoked per day.     

The effects of smoked marijuana on progressive-interval schedule performance in humans.

In three experiments, 8 human subjects participated in a study of the effects of smoked marijuana on progressive-interval schedule performance. A two-component chained progressive-interval fixed-interval schedule of point delivery was used. In the progressive-interval component, the interval length began at 20 s and increased either geometrically or arithmetically (by either 20 s, 40 s, 80 s, 100 s, or 160 s) on each subsequent interval. After this interval elapsed, a single button press produced the fixed-interval component, with a total of five reinforcers of varying magnitude ($0.05, $0.20, or $0.40) available on a fixed-interval 20-s schedule. After the five reinforcer deliveries, the schedule returned to the initial progressive-interval component. Several relationships were found among rates of responding, postreinforcement pauses and drug administration in the progressive-interval component: (a) Postreinforcement pauses increased as the temporal requirements of the progressive-interval schedule increased; (b) rates of responding during successive progressive-interval components rapidly decreased to low rates of responding after the first few progressions; (c) postreinforcement pauses decreased systematically as dose of smoked marijuana increased; and (d) rates of responding increased after smoking active marijuana but not after smoking placebo cigarettes. Results are discussed in the context of behavioral control and relevance to other studies that have investigated the effects of smoked marijuana on schedule performance.     

Marijuana effects on human forgetting functions

It has long been known that acute marijuana administration impairs working memory (e.g., the discrimination of stimuli separated by a delay). The determination of which of the individual components of memory are altered by marijuana is an unresolved problem. Previous human studies did not use test protocols that allowed for the determination of delay-independent (initial discrimination) from delay-dependent (forgetting or retrieval) components of memory. Using methods developed in the experimental analysis of behavior and signal detection theory, we tested the acute effects of smoked marijuana on forgetting functions in 5 humans. Immediately after smoking placebo, a low dose, or a high dose of marijuana (varying in delta9-THC content), subjects completed delayed match-to-sample testing that included a range of retention intervals within each test session (0.5, 4, 12, and 24 s). Performances (discriminability) at each dose were plotted as forgetting functions, as described and developed by White and colleagues (White, 1985; White & Ruske, 2002). For all 5 subjects, both delta9-THC doses impaired delay-dependent discrimination but not delay-independent discrimination. The outcome is consistent with current nonhuman studies examining the role of the cannabinoid system on delayed matching procedures, and the data help illuminate one behavioral mechanism through which marijuana alters memory performance.     

Effects of nicotine dose, instructional set, and outcome expectancies on the subjective effects of smoking in the presence of a stressor

The balanced placebo design (BPD) was used to evaluate the independent effects of nicotine dose and smoking-related expectancies on self-reported anxiety, urge to smoke, and withdrawal symptoms. After anxious mood was induced, participants smoked either a de-nicotinized cigarette or one with standard nicotine content. Nicotine dose was crossed with instructions that the cigarette was either de-nicotinized or standard. Nicotine cigarettes produced greater anxiety reduction than de-nicotinized cigarettes. Nicotine instructions attenuated anxiety only among those who held relevant expectancies. Nicotine dose and instructional set interacted such that either nicotine cigarettes or instructions that the cigarettes contained nicotine were sufficient to reduce urge to smoke. Implications of these findings and methodological issues regarding use of the BPD with cigarettes are discussed.     

Effects of alcohol and marijuana on dynamic visual acuity: I. Threshold measurements

Alcohol and marijuana produce significant dose-related reductions in dynamic visual acuity. Ten subjects participated in a double-blind experiment involving three dose levels of each drug (including placebo). The reduction of DVA produced by alcohol (1.0 ml 95% ethanol/kg body weight) was greater than for marijuana (15 mg Δ-9-tetrahydrocannabinol), and we suggest that this difference was produced by differential oculomotor effects of the two drugs. We have speculated that reduction in DVA under alcohol may be a contributing factor in alcohol-related traffic accidents.     

Aversive smoking therapies: A conditioning analysis of therapeutic effectiveness

Rapid smoking (RS) and a less aversive rapid-puffing (RP) treatment were compared on ability to enhance the impact of a behavioral-counseling (BC) procedure on psychophysiological, attitudinal and behavioral response to cigarettes. Data reveal that both aversive smoking treatments resulted in less smoking once treatment began, reduced smoking in post-treatment taste tests, and superior follow-up performance at 6 months and 1 yr. At 1 yr, RS S s achieved the highest number of days abstinent of any group. Regression analyses showed that Ss' confidence ratings of remaining abstinent were highly predictive of follow-up status, and that these ratings were related to number of cigarettes smoked during treatment and amount of smoking during post-treatment taste tests.     

Marijuana Use Among Daily Tobacco Smokers: Relationship to Anxiety-Related Factors

The present investigation evaluated the incremental validity of regular marijuana use and frequency of such use in relation to anxiety and depressive symptoms and perceived health among young adult tobacco smokers (n = 202). Approximately 72% of the sample were current marijuana smokers, using this drug on an average of 7.6 (SD = 9.2) times per week. As expected, after controlling for theoretically-relevant smoking (cigarettes per day), alcohol use, and affect factors (i.e., negative affectivity and anxiety sensitivity), marijuana use predicted anxiety symptoms and perceived general health, whereas frequency of marijuana use predicted only anxiety symptoms. These results are discussed in relation to better understanding the role of regular marijuana use in terms of anxiety-relevant emotional vulnerability and beliefs about physical health among regular smokers.     

Behavioral performance effects of verapamil in normotensive and renovascular hypertensive baboons.

Behavioral performances of normotensive and hypertensive adult male baboons were tested before, during, and following chronic oral dosing with verapamil. Performances during a five-color simultaneous match-to-sample task were measured for two doses (2.0, and 3.2 mg/kg/day) and vehicle. Each dose was administered for 21 consecutive days preceded and followed by 14-day baseline and recovery periods, respectively. Choice reaction times increased by 9% during the lower dose of verapamil, compared to vehicle; choice reaction times were unchanged at the higher dose. At baseline and during vehicle administration, the yellow and white stimuli were the most difficult to discriminate correctly; discrimination of these colors was slightly impaired by the lower, but not the higher dose of verapamil. Verapamil's behavioral effects were not modulated by blood pressure changes since both baboon groups showed equivalent changes in behavioral performance, but only renovascular hypertensive baboons showed blood pressure decreases. Verapamil appears to be an effective hypotensive and does not produce profound psychomotor impairment at clinically used doses during the first weeks of treatment.     

Behavioral performance effects of verapamil in normotensive and renovascular hypertensive baboons

Behavioral performances of normotensive and hypertensive adult male baboons were tested before, during, and following chronic oral dosing with verapamil. Performances during a five-color simultaneous match-to-sample task were measured for two doses (2.0, and 3.2 mg/kg/day) and vehicle. Each dose was administered for 21 consecutive days preceded and followed by 14-day baseline and recovery periods, respectively. Choice reaction times increased by 9% during the lower dose of verapamil, compared to vehicle; choice reaction times were unchanged at the higher dose. At baseline and during vehicle administration, the yellow and white stimuli were the most difficult to discriminate correctly; discrimination of these colors was slightly impaired by the lower, but not the higher dose of verapamil. Verapamil’s behavioral effects were not modulated by blood pressure changes since both baboon groups showed equivalent changes in behavioral performance, but only renovascular hypertensive baboons showed blood pressure decreases. Verapamil appears to be an effective hypotensive and does not produce profound psychomotor impairment at clinically used doses during the first weeks of treatment.     

Anxiety sensitivity interacts with marijuana use in the prediction of anxiety symptoms and panic-related catastrophic thinking among daily tobacco users

The present investigation evaluated whether anxiety sensitivity interacted with marijuana use in relation to the prediction of panic-relevant variables among young adult tobacco smokers (n=265). Approximately 73% of the sample was composed of current marijuana smokers, with 78.5% of this sub-sample using marijuana more than once per week. As expected, after covarying cigarettes per day, alcohol use, and negative affectivity, the interaction between marijuana use and anxiety sensitivity predicted anxiety symptoms and agoraphobic cognitions. Partially consistent with prediction, the interaction between frequency of marijuana use and anxiety sensitivity predicted only anxiety symptoms. These results are discussed in relation to better understanding the potential role of regular marijuana use and anxiety sensitivity for panic-relevant emotional vulnerability among regular tobacco smokers.     

Interest in Participating in Smoking Cessation Treatment Among Latino Primary Care Patients

Smoking is the leading preventable cause of disease and death for U.S. Latinos. This study identified correlates of interest in participating in a smoking cessation program among urban Latinos seen in community clinics. Interviews were completed with 141 current smokers. Participants were predominantly Spanish-speaking (93%) males (66%), who were on average 37.6 years old and smoked 8.7 cigarettes per day. Over two-thirds (63%) of participants were “definitely interested” in participating in a smoking cessation program. Participants who smoked more cigarettes per day and reported greater nicotine dependence, depression, and readiness to quit were more likely to be interested, while those employed fulltime were less likely to report high interest. Treatment preferences were consistent with Clinical Practice Guidelines recommending counseling, social support, and pharmacotherapy. Results support recommendations that healthcare providers intervene with all Latino smokers, including light smokers and those who do not report initial interest in smoking cessation.     

The Relationship Between Family Factors and Adolescent Substance Use in Rural, Suburban, and Urban Settings

We tested the relationships and predictive power of family factors on rural, suburban, and urban adolescent substance use. A representative statewide survey of 11th grade students for gender, place of residence, and ethnicity was conducted. No significant differences were found between rural, suburban, and urban adolescents for substance use. For family sanction variables across all locations, adolescent substance involvement was significantly lower the more they perceived their families would stop them or care if they got drunk, smoked cigarettes, or used marijuana. Rural and suburban youth who reported that their parents talked to them about the dangers of smoking and getting drunk were less involved in substance use. While controlling for location, gender, and ethnicity, regression analyses showed that family sanctions against smoking cigarettes and marijuana explained a modest proportion of the variance in substance use. Finally, family talking about the dangers of cigarettes, family involvement in schools and belief that their families cared about them predicted lower substance use regardless of location, although minimal variance was explained. The findings have implications for social service providers regarding location settings, prevention, education, and intervention programming.     

Choice between food and heroin: effects of morphine, naloxone, and secobarbital.

Baboons responded on a choice task on which discrete trials involved choosing between an intravenous injection of heroin (.32 or 1.0 mg/kg) or the availability of food pellets. An intertrial interval of three hours followed the completion of each trial. Under baseline conditions baboons consistently completed the eight available trials each day. Typically, animals chose heroin on three or four trials a day and food on the remaining trials. Animals tended to space the selection of heroin rather than choosing heroin on consecutive trials. A series of single-day experimental manipulations was undertaken to characterize performance further. Manipulation of the heroin dose produced shifts in the relative frequency of choosing the drug option which were inversely related to dose. Manipulation of number of pellets per food trial produced little change in distribution of choices. Noncontingent administration of morphine produced dose-related decreases in relative frequency of heroin choices, and a higher dose decreased the number of trials completed. Noncontingent naloxone produced dose-related increases in the relative frequency of heroin choices. Noncontingent secobarbital had no effect on distribution of choices, and high doses reduced the number of trials completed per day. The results suggest that morphine and naloxone produce shifts in this choice behavior by selectively interacting with the reinforcing properties of the option involving heroin.     

Prenatal, perinatal, and early childhood risk factors and drug involvement in adolescence

This study examined prenatal, perinatal, and early childhood risk factors in relation to the etiology of adolescent involvement in cigarettes, alcohol, marijuana, and other illicit drugs. Over a span of 10 years, data were collected on 638 mainly White mother-child pairs at three points in time: at T1, when the children were 1 to 10 years old; at T2, when they were 9 to 18, and again at T3, when they were 11 to 20. Results showed that the early risks of an unwanted pregnancy and major illness were linked to all of the drug categories except "other illicit drugs." Aspects of mutual attachment in the mother-adolescent relationship were negatively correlated with adolescent drug use. Data on the interrelationship of the domains (i.e., sets of variables) of early risk factors and mother-adolescent relations supported an independent model with respect to cigarette and marijuana involvement, a finding in keeping with results showing that early risk did not significantly affect mother-adolescent relations. However, mother-adolescent protective factors were able to mitigate the impact of early risk factors on adolescent drug involvement.     

Feigning Romantic Interest: The Role of Self-Monitoring

In two studies, we examined the extent to which high and low self-monitoring individuals successfully feigned romantic interest in potential dating partners. In Study 1, high self-monitoring men and women reported they would be better at, and would derive more enjoyment from, feigning interest in two different relationship initiation contexts. In Study 2, high self-monitoring men and women were videotaped while they tried to feign interest or lack of interest in an attractive opposite-sex person. Raters evaluated participants' verbal and nonverbal behavior on measures of perceived interest/liking and behavioral cues known to signal romantic interest. When they feigned interest, high self-monitoring men and women were rated as conveying greater interest than low self-monitors through the verbal channel. Additional analyses identified the specific verbal cues that did and did not mediate links between self-monitoring and ratings of verbal interest.     

Personality and judgements of abstract,pop art,and representational paintings

This study was concerned with the question of which personality variables are most predictive of judgements of particular types of painting. One hundred and twenty‐one participants rated 24 slides of abstract, pop art, and representational paintings. They then completed two questionnaires which measured sensation seeking (SS) and the ‘Big Five’ personality dimensions. Thrill and Adventure Seeking was positively correlated with a liking of representational art while Disinhibition was associated with positive ratings of abstract art and pop art. Neuroticism was positively correlated with positive ratings of abstract and pop art, while conscientiousness was linked to liking of representational art. Openness to Experience was linked to positive ratings of all three art types. Agreeableness was negatively linked to liking of pop art. It was also found that art education and frequency of visits to art galleries were linked to positive ratings of abstract paintings. Regressional analyses showed about a fifth of the variance could be accounted for by personality and demographic variables. Personality variables were most strongly linked to positive judgements of representational art and least related to ratings of pop art. Overall the sensation seeking variables accounted for more of the variance than the big five dimensions. Copyright © 2001 John Wiley & Sons, Ltd.     

Identifying Substance Abuse Issues in High Schools: A National Survey of High School Counselors

High school students consistently report the use of substances such as alcohol, cigarettes, and marijuana. One of the people they would talk to about a substance use problem is their school counselor. A survey study was conducted with a national sample of 289 high school counselors. Results indicated that participants were clearly able to identify their practice limitations and future training needs in this area. Implications for training and recommendations for future research are discussed.