A new paradigm for credibly administering placebo alcohol to underage drinkers

Negative mood mind wandering and unsafe driving in young male drivers

OBJECTIVE

Road traffic crash fatalities disproportionately affect young male drivers. Driver distraction is a leading contributor to crashes. Mind wandering (MW) is a prevalent form of driver distraction that is linked to certain unsafe driving behaviours that are associated with increased crash risk (e.g., faster driving). Negative mood can lead to MW, and thus may represent a causal pathway to MW-related unsafe driving. This preliminary pre-post (T1, T2), randomized, controlled, single-blinded experiment tested whether negative mood, compared to neutral mood, increases MW while driving as well as unsafe driving and emotional arousal during MW. It also tested the moderating contribution of trait rumination and inhibitory control to this proposed causal pathway.

METHODS

Forty healthy male drivers aged 20 to 24 were randomly allocated to a negative or neutral mood manipulation involving deception. Individual differences in trait rumination and inhibitory control were measured at T1. At T1 and T2, participants drove in a driving simulator measuring driving speed, headway distance, steering behaviour, and overtaking. Heart rate and thought probes during simulation measured emotional arousal and MW, respectively.

RESULTS

Negative mood exposure led to more MW while driving (Odds Ratio = 1.79, p = .022). Trait rumination positively moderated the relationship between negative mood and MW (Odds Ratio = 2.11, p = .002). Negative versus neutral mood exposure led to increases in headway variability (Cohen's d = 1.46, p = .026) and steering reversals (Rate Ratio = 1.33, p = .032) during MW relative to focused driving. Between-group differences in emotional arousal were not significant.

CONCLUSION

Results support a causal pathway from negative mood to unsafe driving via MW, including the moderating contribution of trait rumination. If replicated, these preliminary findings may inform the development of interventions targeting this potential crash-risk pathway in vulnerable young driver subgroups.

Tripping on nothing: placebo psychedelics and contextual factors

RATIONALE

Is it possible to have a psychedelic experience from a placebo alone? Most psychedelic studies find few effects in the placebo control group, yet these effects may have been obscured by the study design, setting, or analysis decisions.

OBJECTIVE

We examined individual variation in placebo effects in a naturalistic environment resembling a typical psychedelic party.

METHODS

Thirty-three students completed a single-arm study ostensibly examining how a psychedelic drug affects creativity. The 4-h study took place in a group setting with music, paintings, coloured lights, and visual projections. Participants consumed a placebo that we described as a drug resembling psilocybin, which is found in psychedelic mushrooms. To boost expectations, confederates subtly acted out the stated effects of the drug and participants were led to believe that there was no placebo control group. The participants later completed the 5-Dimensional Altered States of Consciousness Rating Scale, which measures changes in conscious experience.

RESULTS

There was considerable individual variation in the placebo effects; many participants reported no changes while others showed effects with magnitudes typically associated with moderate or high doses of psilocybin. In addition, the majority (61%) of participants verbally reported some effect of the drug. Several stated that they saw the paintings on the walls "move" or "reshape" themselves, others felt "heavy… as if gravity [had] a stronger hold", and one had a "come down" before another "wave" hit her.

CONCLUSION

Understanding how context and expectations promote psychedelic-like effects, even without the drug, will help researchers to isolate drug effects and clinicians to maximise their therapeutic potential.

Moderate acute alcohol intoxication increases visual motion repulsion

Among the serious consequences of alcohol abuse is the reduced ability to process visual information. Diminished vision from excessive consumption of alcohol has been implicated in industrial, home, and automobile accidents. Alcohol is also generally recognized as an inhibitor in the brain by potentiating GABA-ergic transmission. In this study, we focused on visual motion processing and explored whether moderate alcohol intoxication induced changes in inhibitory mediated motion repulsion in a center-surround configuration. We conducted a double-blind, placebo-controlled, within-subjects study on the effect of alcohol on visual motion repulsion. Each subject underwent three experimental conditions (no alcohol, placebo and moderate alcohol) on separate days. The order of the placebo and moderate alcohol conditions was counterbalanced. The results showed that the effects of the surround context on the perception of the center motion direction were similar in both the sober (no alcohol) and placebo conditions. However, contextual modulations were significantly stronger during intoxication compared to both the sober and placebo conditions. These results demonstrate that moderate alcohol consumption is associated with altered neural function in visual cortical areas and that motion repulsion deficits might reflect the inhibitory effects of alcohol on the central nervous system.

Effect of anticipatory stress on placebo alcohol consumption in a bar laboratory

BACKGROUND

Only one laboratory study has examined the relation between stress and alcohol use in an ecologically valid drinking context. In that prior study, drinking was measured after the stressful situation.

OBJECTIVE

To examine the effect of an anticipatory stressor, and trait social anxiety on "alcohol" consumption in a bar laboratory.

METHODS

College students aged 18 and older (N = 127) in same-sex groups of two or three participants took part in a study that ostensibly examined alcohol's effect on language fluency. Using a between-subjects design, participants were randomly assigned to a stress or control condition. Participants in the stress condition anticipated giving a stressful speech for the fluency procedure, whereas those in the control group anticipated a nonstressful activity. Before the alleged fluency task, groups could order and consume mixed drinks ad lib in a bar laboratory. No beverages actually contained alcohol, but we used a validated procedure to ensure that participants included in these analyses were deceived. Primary analyses were performed with a hierarchical linear model (HLM) due to a substantial group/modeling effect.

RESULTS

Counter to expectations, participants in the control group consumed more placebo alcohol than those in the stress condition. This main effect was moderated by past 3 months' drinks per week, such that the effect was attenuated (or reversed) among heavy drinkers. No main or interaction effects were observed for trait social anxiety.

CONCLUSIONS

Some stressors (i.e., those invoking performance anxiety) may decrease consumption. People with higher levels of alcohol involvement might be especially motivated to drink for tension reduction purposes.