Subjective Measures Of Intoxication Research Articles

62 Exploration of Sex Differences in Cannabis Use Patterns, Driving Performance, and Subjective Intoxication Effects

Objective:Although some animal research suggests possible sex differences in response to THC exposure (e.g., Cooper & Craft, 2018), there are limited human studies. One study found that among individuals rarely using cannabis, when given similar amounts of oral and vaporized THC females report greater subjective intoxication compared to males (Sholler et al., 2020). However, in a study of daily users, females reported indistinguishable levels of intoxication compared to males after smoking similar amounts (Cooper & Haney, 2014), while males and females using 1–4x/week showed similar levels of intoxication, despite females having lower blood THC and metabolite concentrations (Matheson et al., 2020). It is important to elucidate sex differences in biological indicators of cannabis intoxication given potential driving/workplace implications as states increasingly legalize use. The current study examined if when closely matching males and females on cannabis use variables there are predictable sex differences in residual whole blood THC and metabolite concentrations, and THC/metabolites, subjective appraisals of intoxication, and driving performance following acute cannabis consumption.Participants and Methods:The current study was part of a randomized clinical trial (Marcotte et al., 2022). Participants smoked ad libitum THC cigarettes and then completed driving simulations, blood draws, and subjective measures of intoxication. The main outcomes were the change in Composite Drive Score (CDS; global measure of driving performance) from baseline, whole blood THC, 11-OH-THC, and THC-COOH levels (ng/mL), and subjective ratings of how “high” participants felt (0 = not at all, 100 = extremely). For this analysis of participants receiving active THC, males were matched to females on 1) estimated THC exposure (g) in the last 6 months (24M, 24F) or 2) whole blood THC concentrations immediately post-smoking (23M, 23F).Results:When matched on THC exposure in the past 6 months (overall mean of 46 grams; p = .99), there were no sex differences in any cannabinoid/metabolite concentrations at baseline (all p > .83) or after cannabis administration (all p > .72). Nor were there differences in the change in CDS from pre-to-post-smoking (p = .26) or subjective “highness” ratings (p = .53). When matched on whole blood THC concentrations immediately after smoking (mean of 34 ng/mL for both sexes, p = .99), no differences were found in CDS change from pre-to-post smoking (p = .81), THC metabolite concentrations (all p > .25), or subjective “highness” ratings (p = .56). For both analyses, males and females did not differ in BMI (both p > .7).Conclusions:When male/female cannabis users are well-matched on use history, we find no significant differences in cannabinoid concentrations following a mean of 5 days of abstinence, suggesting that there are no clear biological differences in carryover residual effects. We also find no significant sex differences following ad libitum smoking in driving performance, subjective ratings of “highness,” nor whole blood THC and metabolite concentrations, indicating that there are no biological differences in acute response to THC. This improves upon previous research by closely matching participants over a wider range of use intensity variables, although the small sample size precludes definitive conclusions.

Predicting perceived safety to drive the morning after drinking: The importance of hangover symptoms.

People driving the day after drinking are at risk of impaired performance and accidents due to continued intoxication or the effects of alcohol hangover. Drivers are poor at estimating their own blood alcohol concentration, and some drive despite believing they are over the legal limit. It is therefore important to identify other factors influencing perceived ability to drive 'the morning after'. This study tested how accurately participants estimated their legal driving status, and the contribution of beliefs and hangover symptoms to the prediction of perceived driving safety. This cross-sectional study involved 193 students completing a questionnaire and alcohol breath test the morning after heavy alcohol consumption. Indicators of subjective intoxication, severity of hangover symptoms, estimated legal status and perceived safety to drive were measured. A hierarchical linear regression analysis was conducted. No participants thought they were under the English legal limit when they were not, and 47% thought they were over the limit when they were in fact legally permissible to drive. However, 20% of those believing they were over the limit nevertheless rated themselves as safe to drive. Hangover symptoms added 17% variance to the prediction of perceived safety to drive, over and above objective and subjective measures of intoxication. Perceived severity of hangover symptoms influence beliefs about driving ability: When judging safety to drive, people experiencing less severe symptoms believe they are less impaired. If this finding is robust, health promotion campaigns should aim to correct this misapprehension. [Cameron E, French D. Predicting perceived safety to drive the morning after drinking: The importance of hangover symptoms. Drug Alcohol Rev 2016;35:442-446].

The Impact of Alcohol and Energy Drink Consumption on Intoxication and Risk-Taking Behavior

It has been argued that consuming alcohol mixed with energy drinks (AmED) causes a subjective underestimation of intoxication and an increased level of risk-taking behavior. To date, however, there is mixed support for AmED-induced reductions in perceived intoxication, and no objective assessment of risk-taking following AmED consumption. Consequently, the present study aimed to determine the effect of alcohol and energy drink (ED) consumption on subjective measures of intoxication and objective measures of risk-taking. Using a placebo-controlled, single-blind, cross-over design, participants (n = 28) attended 4 sessions in which they were administered, in counterbalanced order: 0.5 g/kg alcohol, 3.57 ml/kg ED, AmED, and a placebo beverage. Participants completed the Biphasic Alcohol Effects Scale and a Subjective Effects Scale at baseline and 30 and 125 minutes postbeverage administration; risk-taking was measured using the Balloon Analogue Risk Task (BART). Participants reported greater subjective intoxication, impairment, and sedation after active relative to placebo alcohol consumption, with no interactive AmED effects. However, a significant moderate magnitude increase in stimulation ratings was observed in the AmED relative to alcohol, ED, and placebo conditions. There was no independent effect of alcohol, or interactive effect with ED, on the BART. A significant, yet small magnitude, increase in risk-taking was evident in active relative to placebo ED conditions. The interactive effect of AmED appears restricted to perceived stimulation, with alcohol-induced increases in subjective intoxication occurring regardless of presence or absence of ED. Engagement in risk-taking behavior was only increased by ED consumption; however, this effect was only of small magnitude; at these doses, alcohol consumption, with or without EDs, did not affect risk-taking. Further research assessing the dose-dependent effects of AmED on objectively measured risk-taking behavior could clarify whether the ED effect increases with higher doses and whether an interactive effect is observed with higher alcohol doses.

Kudzu extract treatment does not increase the intoxicating effects of acute alcohol in human volunteers.

Isoflavone administration in the form of a purified extract from the herbal medication kudzu root has been shown to reduce, but not eliminate, alcohol consumption in alcohol-abusing and alcohol-dependent men. The precise mechanism of this action is unknown, but 1 possible explanation for these results is that the isoflavones in kudzu might actually increase the intensity or duration of alcohol's effects and thus delay the desire for subsequent drinks. This study was designed to test this hypothesis. Twelve (12) healthy adult men and women (27.5 ± 1.89 years old) who consumed moderate amounts of alcohol (7.8 ± 0.63 drinks/wk) participated in a double-blinded, placebo-controlled crossover study in which they were treated with either kudzu extract (total isoflavone dose of 750 mg/d) or matched placebo for 9 days. On days 8 and 9, participants received an acute challenge of ethyl alcohol (either 0.35 or 0.7 g/kg alcohol). During the challenges, the following measures were collected: subjective effects, psychomotor (body sway), cognitive performance (vigilance/reaction time), physiological measures (heart rate and skin temperature), and plasma ethanol concentration. Alcohol resulted in a dose-related alteration in subjective measures of intoxication, impairment of stance stability, and vigilance/reaction time. Kudzu extract did not alter participants' subjective responses to the alcohol challenge or to alcohol's effects on stance stability or vigilance/reaction time. However, individuals treated with kudzu extract experienced a slightly more rapid rise in plasma ethanol levels, but only after the 0.7 g/kg dose. This transient effect during the first 30 minutes of the ascending plasma alcohol curve lasted only 10-15 minutes; there were no differences in peak plasma alcohol levels or alcohol elimination kinetics. Additionally, kudzu pretreatment enhanced the effects of the 0.7 g/kg dose of alcohol on heart rate and skin temperature. These data suggest that individuals who drink alcohol while being treated with kudzu extract experience no adverse consequences, and furthermore the reported reductions in alcohol intake after kudzu extract treatment are not related to an alteration in alcohol's subjective or psychomotor effects.

Effects of moderate dose alcohol on visual contrast sensitivity for stationary and moving targets.

Contrast sensitivity involves distinguishing threshold luminance differences and is usually assessed using static sine-wave gratings over a range of different spatial frequencies. The purpose of this study was to determine the effects of various levels of acute alcohol intoxication on contrast sensitivity to stationary and moving sine-wave gratings. Moving gratings required the subjects to make pursuit eye movements. A secondary goal was to investigate whether any alcohol-related effects were associated with any measures of intoxication. Male volunteers (N = 8) participated in three counterbalanced, double-blind, testing sessions (low alcohol, moderate alcohol and placebo) plus a control session with no beverage. Breath alcohol concentration and two subjective measures of intoxication were measured for each subject. Static and dynamic contrast sensitivity were determined for electronically generated sine-wave gratings that were either stationary or traveled in a circular path with a diameter of 9 cm (3.7 degrees) at 51.7 rpm, thus requiring the subject to make smooth pursuit eye movements. The mean blood alcohol concentration measured in the moderate alcohol condition was 0.043% and in the low alcohol condition 0.011%. Moderate dose alcohol consumption significantly impaired both static and dynamic contrast with a greater effect for moving targets. Objective and subjective measures of intoxication were unrelated to the alcohol-related losses in contrast sensitivity. Although most states currently prohibit driving with BACs of 0.08-0.10%, the present data indicate reliable visual impairment at approximately half of that level (.44%).

Behavioral and physiological effects of ethanol in high-risk and control children: a pilot study.

Blood and breath acetaldehyde levels were measured following ethanol ingestion (0.5 ml/kg) in 11 boys familially at risk for alcoholism and 11 age-matched controls. No significant differences were found between groups for acetaldehyde, objective, or subjective measures of intoxication. Previous reports of acetaldehyde as a marker of risk for alcoholism were not confirmed. Baseline behavioral state predicted response to alcohol. Children tended to have a subjective response in a direction opposite from the baseline mood state.

Biological markers: Metabolism and acute reactions to alcohol in sons of alcoholics

Substantial evidence has accumulated to indicate that defined aspects of primary alcoholism may be inherited. Family history studies, genetic marker studies, twin studies and adoption studies all contribute to this conclusion. Current studies of possible biological mediators of predisposing factors indicate that men with a family history of alcoholism exhibit higher circulating levels of acetaldehyde after ingestion of ethanol compared to control subjects. Subjects with a family history of alcoholism also respond differently from controls on subjective measures of intoxication and on physiologic measures of ethanol's effects.

Time course effects of marijuana and ethanol on event-related potentials

Twelve male college students received orally on different days NIMH marijuana extract calibrated to contain 0.7 mg/kg delta-9-tetrahydrocannabinol, 1.0 ml/kg 95% ethanol, and placebo in a double-blind balanced-order design. The contingent negative variation (CNV), auditory evoked potential (EP), heart rate (HR), and subjective measures of intoxication were recorded prior to drug ingestion and at regular intervals for 4.5 h postdrug. Both drugs produced significant subjective effects. Marijuana increased HR but did not have a significant effect on CNV amplitude or EP peak amplitudes and latencies. Ethanol increased HR, but not significantly, and reduced CNV amplitude and N1-P2 amplitude. Time-action curves for ethanol's effect on subjective high, HR, and N1-P2 amplitude were parallel, peaking between 0.5 and 1.5 h postdrug and returning to baseline by the end of testing. Time-action curve for ethanol's effect on the CNV showed continuing amplitude reduction throughout the test session.

The disruption of marijuana intoxication

Ninety-six males Ss were divided into four drug conditions; coltsfoot, placebo, marijuana low dose, and marijuana high dose. Half of the Ss smoked marijuana while listening to music in a relaxing environment, and half smoked marijuana in the same environment but had two 10-min periods of aversive-noise superimposed over the music. A subjective measure of intoxication demonstrated significant drug and environmental group effects with suppression of self-report of intoxication being especially strong for the marijuana low dose noise group. The usual positive correlation between subjective measures and pulse rate measures of marijuana intoxication was interfered with by the noise effect. Although subjective ratings were suppressed, the noise group demonstrated significantly higher pulse rates than the music group. The results are discussed in terms of the effect of extraneous factors on marijuana intoxication, the significance of dosage in this type of research, and the nature of marijuana intoxication.