A PC-Based Software Test for Measuring Alcohol and Drug Effects in Human Subjects

A new software-based visual search and divided-attention test of cognitive performance was developed and evaluated in an alcohol dose-response study with 24 human subjects aged 21–62 years. The test used language-free, color, graphic displays to represent the visuospatial demands of driving. Cognitive demands were increased over previous hardware-based tests, and the motor skills required for the test involved minimal eye movements and eye-hand coordination. Repeated performance on the test was evaluated with a latin-square design by using a placebo and two alcohol doses, low (0.48 g/kg/LBM) and moderate (0.72 g/kg/LBM). The data on 7 females and 17 males yielded significant falling and rising impairment effects coincident with moderate rising and falling breath alcohol levels (mean peak BrALs = 0.045 g/dl and 0.079 g/dl). None of the subjects reported eye-strain or psychomotor fatigue as compared with previous tests. The high sensitivity/variance relative to use in basic and applied research, and worksite fitness-for-duty testing, was discussed. The most distinct advantage of a software-based test that operates on readily available PCs is that it can be widely distributed to researchers with a common reference to compare a variety of alcohol and drug effects.     

Assessing Alcohol Problems in Female DWI Offenders

The severity of alcohol problems in a sample of 812 women driving while intoxicated (DWI) offenders enrolled in a Drinking Driver Program in New York State was assessed through the use of multiple measures. These women voluntarily provided information through a self-administered questionnaire completed at the beginning of the program. Classification of alcohol problems based on DSM-III-R criteria was compared with classification based on the use of alcohol-specific and nonalcohol-specific measures of alcohol-related problems. Greater hostility and a larger number of drinks ever consumed accounted for nearly 12% of the variance between no diagnosis and alcohol abuse women, whereas these two variables plus age, race, depression, and having a relative with alcohol problems accounted for nearly 41% of the variance between alcohol abuse and dependent women. A subsample of women within each DSM-III-R diagnostic group showed high risk for later, more severe alcohol problems. Multiple measures of alcohol problems help to elucidate subtle differences in alcohol problems within each of the broad categories specified by the DSM, and should facilitate more appropriate intervention and treatment plans for women DWI offenders with alcohol-related problems.     

Effects of Alcohol on Performance on a Distraction Task During Simulated Driving

Background:  Prior studies report that accidents involving intoxicated drivers are more likely to occur during performance of secondary tasks. We studied this phenomenon, using a dual-task paradigm, involving performance of a visual oddball (VO) task while driving in an alcohol challenge paradigm. Previous functional MRI (fMRI) studies of the VO task have shown activation in the anterior cingulate, hippocampus, and prefrontal cortex. Thus, we predicted dose-dependent decreases in activation of these areas during VO performance.
Methods:  Forty healthy social drinkers were administered 3 different doses of alcohol, individually tailored to their gender and weight. Participants performed a VO task while operating a virtual reality driving simulator in a 3T fMRI scanner.
Results:  Analysis showed a dose-dependent linear decrease in Blood Oxygen Level Dependent activation during task performance, primarily in hippocampus, anterior cingulate, and dorsolateral prefrontal areas, with the least activation occurring during the high dose. Behavioral analysis showed a dose-dependent linear increase in reaction time, with no effects associated with either correct hits or false alarms. In all dose conditions, driving speed decreased significantly after a VO stimulus. However, at the high dose this decrease was significantly less. Passenger-side line crossings significantly increased at the high dose.
Conclusions:  These results suggest that driving impairment during secondary task performance may be associated with alcohol-related effects on the above brain regions, which are involved with attentional processing/decision-making. Drivers with high blood alcohol concentrations may be less able to orient or detect novel or sudden stimuli during driving.     

Ethnic differences in driving after drinking and riding with drinking drivers among adolescents

BACKGROUND: This study examined the relationship between ethnicity and driving after drinking (DD) and riding with drinking drivers (RWDD) while controlling for drinking patterns, driving practices, and background demographic characteristics including age and gender. METHODS: Using random-digit dialing procedures, 1534 young adults ranging from 15- to 20-years of age(mean = 17.6) living in California were recruited to participate in a telephone survey. Latinos, African Americans, and Asian Americans were oversampled to allow cross-group comparisons. RESULTS: Rates of DD were lower for females than for males and were also lower for African Americans and Asian Americans than for whites. However, after we controlled for drinking patterns and driving practices, the results showed Latinos at greater risk for DD than white adolescents. Compared with whites and males, Asian American and female adolescents were less likely to report RWDD. When drinking patterns and driving practices were taken into account, Latino adolescents were nearly twice as more likely to ride with drinking drivers than whites. CONCLUSIONS: These findings indicate a greater need for directing prevention efforts to target Latino youth and youth at risk. Moreover, research aimed at elucidating the social and environmental factors involved in the low prevalence rates of DD and RWDD among Asian American youth may indicate possible protective factors to DD and RWDD operating within the Asian American community.     

Alcohol Effects on Mood, Equilibrium, and Simulated Driving

BACKGROUND: The effects of alcohol on simple versus complex psychomotor performance were compared in 18 adults. METHODS: Subjects received ethanol doses of 0.0, 0.5, and 0.8 g/kg in a randomized, double-blind, within-subject design. Forty minutes after finishing their drinking, the subjects completed a 60-min battery of tests that included: 1) a sensory organization posturography test (EquiTest); 2) latency to apply the brake after appearance of a barrier in a driving simulator (brake reaction time); 3) visual analog subjective-effects scales (VAS); 4) the Profile of Mood States (POMS); 5) critical flicker fusion (CFF); and 6) choice reaction time (CRT). RESULTS: Alcohol dose dependently reduced composite equilibrium scores and increased brake reaction time. On the CRT task, total reaction time was significantly increased after the high dose but not the low dose. Alcohol dose dependently increased VAS "dizzy," "high," and "drug effect" ratings. The POMS and CFF were not significantly affected by alcohol. CONCLUSIONS: These data suggest that an ethanol dose that neither influences certain mood states nor impairs simple psychomotor task performance nonetheless may impair equilibrium and complex psychomotor tasks (e.g., driving).     

Effects of alcohol on simulated driving and perceived driving impairment in binge drinkers

Background:  Binge drinking (heavy episodic alcohol use) is associated with high rates of impaired driving and myriad alcohol-related accidents. However, the underlying reasons for the heightened accident risk in this demographic group are not known. This research examined acute alcohol effects on simulated driving performance and subjective ratings of intoxication and driving ability in binge and nonbinge drinkers.
Methods:  Young social drinking college students (24 binge drinkers and 16 nonbinge drinkers) participated in this study. Participants attended a session during which they received a moderate dose of alcohol (0.65 g/kg) and a session during which they received a placebo. A simulated driving task measured participants' driving performance in response to each dose. Subjective responses to each dose were also assessed, including ratings of sedation, stimulation, and driving ability.
Results:  The acute dose of alcohol impaired multiple aspects of driving performance in both binge and nonbinge drinkers. Under alcohol, all participants had greater difficulty in maintaining their lane position, maintaining the appropriate speed and made multiple driving errors compared to placebo performance. By contrast, compared with nonbinge drinkers, binge drinkers reported feeling less sedated by the alcohol and reported having a greater ability to drive following the acute dose of alcohol.
Conclusions:  Reduced subjective intoxication and perceived driving impairment in binge drinkers may account for the greater accident risk in this demographic group. Binge drinkers may lack the internal sedation cue that helps them accurately assess that they are not able to effectively drive a vehicle after drinking.     

Alcohol availability as a predictor of youth drinking and driving: a hierarchical analysis of survey and archival data

BACKGROUND: Much attention has recently been directed toward developing preventive interventions to reduce drinking and driving through efforts to limit the numbers and locations of alcohol outlets at the community level. Although evaluations of these efforts have suggested linkages between alcohol outlets and problem outcomes, they have not addressed the linkage between outlets and drinking and driving among youth. The analysis reported here investigates the relationship between alcohol outlet densities and underage drinking and driving as self-reported on two telephone surveys conducted in California. METHODS: These analyses were based on data obtained from two telephone surveys conducted by the Prevention Research Center and archival data collected by the California Department of Alcoholic Beverage Control and the US Census Bureau. The sample for the first survey consisted of 15- to 20-year-old adolescents and young adults contacted by telephone, using a random digit dialing of exchanges in the greater San Francisco Bay Area. A second set of survey data was similarly collected by a random sample of households throughout California, and the Bay Area subset was also used for this analysis. RESULTS: At the individual level, older respondents were more likely to report drinking and driving and riding with drinking drivers, whereas females and Asians were less so. At the aggregate or city-level, alcohol outlet density, as measured by the number of on- and off-premises establishments licensed to sell alcohol, was associated with both drinking and driving and riding with drinking drivers. These effects were moderated by a number of individual level effects, with younger respondents and females more likely to be affected by outlet densities. CONCLUSIONS: The findings here provide support for the implementation of policies targeting alcohol outlet density reductions. Areas with large numbers of such outlets provide ample opportunities to youth for alcohol purchases.     

Driving Behavior of Alcohol,Cannabis, and Cocaine Abuse Treatment Clients and Population Controls

Background/Introduction: A paucity of research exists on driving after use of cannabis or cocaine among clients in substance abuse treatment and changes in this behavior after treatment. Objectives: The objectives of this research are to compare treatment clients and population controls before and after treatment in terms of: 1) amount of driving; 2) alcohol, cannabis, and cocaine consumption; 3) driving after use of alcohol, cannabis, and cocaine; and 4) driving infractions. Method: Telephone interviews were conducted with a sample of 110 clients who received treatment in 1995 for a primary problem of alcohol (n = 44), cannabis (n = 37), or cocaine (n = 29) abuse. A random sample of 104 drivers from the general population, frequency matched by age and sex was also interviewed. Participants were asked to describe their driving habits and driving infractions before and after 1995. Results: Both treatment and control groups reported about the same amount of driving. The treatment group reported significantly more consumption of alcohol, cannabis, and cocaine than did the control group before treatment. Significant declines in use for each substance were found for the treatment group after treatment, but use for the control group remained stable over the two time periods. Similarly significant declines in driving after use of alcohol, cannabis, and cocaine were found for the treatment group but the control group remained stable. Finally driving infractions, including speeding tickets, collisions, and license suspensions, significantly declined for the treatment group but not the control group. Discussion: The results confirm that before treatment, the treatment subjects drove more frequently after consuming alcohol, cannabis, or cocaine than the control group. Declines in substance use and driving after treatment were accompanied by reductions in some types of driving infractions. Differences between groups, and over time in terms of driving while under the influence of psychoactive substances better explain the results than differences between groups in impulsivity/risk‐taking or sleep problems.     

Functioning of alcohol use disorder criteria among men and women with arrests for driving under the influence of alcohol

Background: Many states require screening of individuals arrested for driving under the influence (DUI) of alcohol to determine recidivism risk and the need for treatment based on severity of alcohol problems. Several screening instruments use DSM‐IV criteria for alcohol abuse and dependence to assess alcohol problems in this population, but whether they adequately measure alcohol problems in individuals with DUIs has not been examined. In addition, gender differences in DUI samples suggest that female offenders have more severe alcohol problems than male offenders. The current study examines differences in alcohol criteria functioning by DUI history and gender using an item response theory (IRT) approach. Methods: Data from diagnostic interviews with 8,605 participants in the Collaborative Study on the Genetics of Alcoholism, including 1,655 who ever reported a DUI arrest (20% women), were used to examine differences in alcohol criteria functioning between men and women with and without DUIs. The factor underlying item response was conceptualized as unidimensional, representing alcohol problem severity. Results: Social/interpersonal problems, larger/longer, and inability/persistent desire to quit displayed greater discrimination of IRT‐defined alcohol problem severity among individuals with DUIs than those without. Irrespective of DUI status, women had a higher threshold than men for time spent drinking or recovering. Women without DUIs had a higher threshold than similar men for social/interpersonal problems. Taken as a whole, the criteria yielded similar amounts of information in all groups. Conclusions: DSM‐IV criteria for alcohol abuse and dependence adequately detect alcohol problem severity in individuals with DUIs, and some are better at detecting severity in this particularly high‐risk group than in individuals without DUIs. However, the criteria as a whole are equally effective in measuring alcohol problem severity among individuals with and without DUIs and may be used with confidence in screening DUI offenders.     

The Identification of Alcohol Intoxication by Police

BACKGROUND: The identification of alcohol intoxication by police, bartenders, social hosts, and potential passengers is an important issue in the prevention of alcohol-related driving accidents. This study examines the ability of police officers to correctly identify and make ratings of the sobriety of target drinkers presented on video. METHODS: Raters were asked to determine (1) whether the target drinker had been drinking alcohol, (2) whether it was "okay" to serve the target another drink, and (3) whether the target drinker was "okay" to drive. A rater confidence score for each target evaluated, as well as demographic characteristics about the raters, was obtained. RESULTS: Drinkers were accurately targeted to low (0.08-0.09%), medium (0.11-0.13%), and high (0.15-0.16%) blood alcohol concentrations (BACs) by using a method previously described. At lower BACs, most police officers were unable to identify whether or not targets had been drinking. Raters were "pretty sure" that targets in the 0.15-0.16% range had been drinking and "not sure" whether or not they should be served another drink or drive a car. CONCLUSIONS: The ability of raters to reliably identify target drinkers who were too intoxicated to drive safely was not obtained until the BACs were relatively high. These results suggest that prevention measures must focus on improving behavioral observations made of potential drunk drivers. Implications for bartenders and social hosts are discussed.