The Effects of ß-myrcene on Simulated Driving and Divided Attention: A Double-Blind, Placebo-Controlled, Crossover Pilot Study.

Background: ß-myrcene, one of the most common terpenes found in cannabis, has been associated with sedation. We propose that ß-myrcene contributes to driving impairment even in the absence of cannabinoids. Aim: To conduct a double-blind, placebo-controlled crossover pilot study of the effect of ß- myrcene on performance on a driving simulator. Method: A small sample (n=10) of participants attended two experimental sessions, one in which they were randomized to receive 15 mg of pure ß-myrcene in a capsule versus a canola oil control. Each session, participants completed a baseline block and three follow-up blocks on a STISIM driving simulator. Results: ß-myrcene was associated with statistically significant reductions in speed control and increased errors on a divided attention task. Other measures did not approach statistical significance but fit the pattern of results consistent with the hypothesis that ß-myrcene impairs simulated driving. Conclusions: This pilot study produced proof-of-principle evidence that the terpene ß-myrcene, an agent commonly found in cannabis, can contributes to impairment of driving-related skills. Understanding how compounds other than THC affect driving risk will strengthen the field's understanding of drugged driving.

A Latent Class Analysis of DUI Offender Motivation and Awareness as Predictors of Performance While on Alcohol Ignition Interlocks.

INTRODUCTION: Alcohol ignition interlock devices (IID) reduce rates of drinking and driving. The interlock offers an opportune time for tailoring targeted interventions to develop habits to separate drinking from driving among this high-risk population. This study identified different types of IID users upon whom targeted interventions could be developed. METHODS: Participants (N = 114) were assessed at IID installation and again six months later. Latent class analysis (LCA) was conducted using drinking environment, drinking motivation, social support, drug use, and problem drinking behaviors as indicators. Multivariate regression analyses were conducted comparing latent class assignment with impaired driving attempts. RESULTS: LCA supported a 4-class model where 14.8% of participants fell into the low use/high awareness class; 30.6% fell into the heavy use/high awareness class; 30.6% fell into the mixed use/high awareness class; and 24.0% fell into the moderate use/low awareness class. Drivers in the moderate use/low awareness condition had increased early morning BAC lockouts. CONCLUSIONS: These typologies demonstrate important differences within high risk drivers. Indeed, drivers who fell into the moderate use/low awareness class may not have considered their alcohol-related behaviors problematic. This information could lend itself to the development of targeted interventions to address subgroups of drinking drivers.

Understanding non-installers of the ignition interlock device: A qualitative analysis.

INTRODUCTION: Literature notes the efficacious use of alcohol ignition interlock devices (IID) in reducing rates of drinking and driving while installed on the vehicle. Some drivers who are convicted of driving while intoxicated (DWI) elect to have their license suspended/revoked instead of installing the device. These individuals represent a high-risk subsample of drivers, yet limited literature has addressed this concern. The current study seeks to fill this gap using qualitative interviews addressing: (i) why do non-installers make the choice to not install a mandated IID; and (ii) how are non-installers managing without the IID? METHODS: The study utilises the Managing Heavy Drinkers study of drivers in Erie County, New York, USA. Participants were purposively sampled from a group of non-installers (n = 6; four females, two males) who completed semi-structured interviews. Constructed grounded theory was used to develop a theoretical understanding of participant's experiences. RESULTS: To understand why participants elect not to install the IID, thematic analysis revealed: alleviating constraints, predominantly the financial burdens associated with an IID, and institutional mistrust. Additionally, data revealed that participants are managing without the IID by mitigating apprehension. This included driving cautiously to avoid detection and utilising alternative transportation. DISCUSSION AND CONCLUSIONS: This study furthers understanding of why drivers convicted of a DWI elect not to install an IID. Future research should seek to identify barriers to IID installation. This work provides evidence for establishing institutional protocols that ensure drivers convicted of a DWI receive consistent and correct information about the IID process.

The impact of interlock installation on driving behavior and drinking behavior related to driving.

OBJECTIVE: There is a substantial body of evidence that the recidivism of impaired-driving offenders is reduced while an ignition interlock device (IID) is on their vehicles. This study examines changes in driving behaviors and drinking behaviors used by DWI offenders to manage driving with the IID. METHODS: A total of 166 IID participants who completed two surveys covering the period from arrest to IID installation (T1) and during IID use (T2) were examined. Four domains were covered: demographics, driving environments and transportation needs, reported driving activity, and reported drinking activities. Participants were on average 38 years old, 43% were female, 35% completed college, 34% had an income of more than $50,000, and 83% were employed. For those who provided it, the mean blood alcohol content (BAC) at arrest was .184 g/dL, with only 8 (5%) individuals below .08 g/dL, and 93 (56%) at over .18 g/dL. About 45% were repeat DWI offenders. RESULTS: Between T1 and T2 there was a slight increase in acknowledging public transportation was available (p=.001), an increase in other individuals driving the interlock-equipped vehicle (p=.002), an increase in the number of vehicles in the household not registered to the DWI offender (p< .001), and an increase in the number of participants who reported that driving was important to their lifestyle (p=.008). Initial (T1) expectations about whether the interlock would be a problem were significantly different from actual experiences reported in T2 (p<.001). With respect to alcohol consumption, 14% reported abstinence at T2 compared to 2% at T1 (p=.001) and the number of drinks per drinking occasion decreased from a mean of 4.90 at T1 to 3.14 at T2 (p=.001), but the number of drinking occasions increased by a third (p=.003). The number of drinking locations (p=.001), the frequency of stopping after work for a drink (p=.001), and drinking at a bar all decreased (p<.001). CONCLUSIONS: Interlock users make some adjustments in how they drink, the amount they drink, and where they drink. This finding suggests that there may be methods that can be used to extend the benefits of the IID beyond the sanction period.

The Illinois .08 law. An evaluation.

Lowering state blood alcohol concentration (BAC) limits to 0.08, though controversial, has been supported by most evaluation studies to date. The Illinois .08 BAC law implemented in 1997 provided a unique opportunity to evaluate the effect of the law without the simultaneous passage of an administrative license revocation (ALR) law, which has clouded some previous evaluations of the .08 laws. The proportion of all drinking drivers in fatal crashes was compared before versus after implementing the .08 law using time-series analysis to evaluate 12 years of fatal crash data for Illinois and five bordering states. The results showed that the proportion of drinking drivers in fatal crashes decreased by 14% in Illinois and increased by 3% in bordering states. The proportion of drinking drivers in fatal crashes in Illinois, though increasing since 1995, was sharply reduced after passage of the .08 law in 1997, saving more than 100 lives in 1998 and 1999 than it would have without the .08 law.