Effectiveness of contingency management using transdermal alcohol monitoring to reduce heavy drinking among driving while intoxicated (DWI) arrestees: A randomized controlled trial

BACKGROUND

Driving while intoxicated (DWI) is a serious public health problem. However, treatment for DWI arrestees is not readily available. This study examines the effectiveness of a contingency management (CM) procedure using transdermal alcohol concentration (TAC) monitoring to reduce drinking among DWI arrestees.

METHOD

The study participants were 216 DWI arrestees under pretrial and included both Mandated participants undergoing court-ordered TAC monitoring and Non-Mandated participants wearing a study-provided TAC monitor. Participants were randomly assigned to either a CM (Mandated = 35; Non-Mandated = 74) or a Control condition (Mandated = 37; Non-Mandated = 70) and completed the 8-week intervention. CM participants received $50/week for not exceeding a TAC of 0.02 g/dL during the previous week. Payments to Controls were yoked to the CM group.

RESULTS

Among Non-Mandated participants, the probability of meeting the contingency was higher and remained stable (about 65%) over time in the CM group, whereas the probability was lower and declined in the Control group, widening the gaps in the probability between the study conditions (16.7%-24.1% greater in the CM group from visit 4 to 8, all p < 0.05). Among Mandated participants, the probability was not significantly different between conditions (p = 0.06-0.95). Furthermore, among Non-Mandated participants, the percentage of heavy drinking days remained low (9.16%-11.37%) in the CM group, whereas it was greater and increased over time (17.43%-26.59%) in the Control group. In Mandated participants, no significant differences in percent heavy drinking days were observed between conditions (p = 0.07-0.10).

CONCLUSION

We found that contingency effects on alcohol use are more pronounced among frequent and heavy alcohol users, i.e., Non-Mandated DWI arrestees. However, for individuals whose drinking was already suppressed by existing contingencies (i.e., court-mandated TAC monitoring), our CM procedure did not produce additional reductions in drinking.

The age-varying effects of adolescent stress on impulsivity and sensation seeking

Adolescence is defined in part by heightened exposure and sensitivity to stressors. In a longitudinal cohort of youth at risk for substance use problems, we examined the age-varying relationship between stress exposure and traits that are central to the dual systems model. The positive associations between stress exposure, impulsivity, sensation seeking varied as function of age. Specifically, the influence of stress exposure on impulsivity strengthened during early adolescence and remained stable into early adulthood, while the influence of stress exposure on sensation seeking strengthened from early- to mid-adolescence and weakened thereafter. These findings suggest that the maturational imbalance between the capacity to regulate impulsive tendencies and sensation seeking may be exaggerated for youth who are exposed to a high number of stressors.

Reduced alcohol use increases drink-refusal self-efficacy: Evidence from a contingency management study for DWI arrestees

BACKGROUND

Several therapies and interventions to reduce drinking first target drink-refusal self-efficacy (DRSE) to influence drinking behavior. While higher self-efficacy scores are correlated with better outcomes, it is unclear that increased self-efficacy is the causative step leading to improved outcomes. Instead, this correlation may result from reduced drinking that increased self-efficacy. The current study sought to understand how changes in drinking behavior can influence DRSE.

METHODS

Data were from 211 driving while intoxicated (DWI) arrestees participating in an 8-week contingency management (CM) study to reduce drinking. Some of participants were mandated by the courts to wear transdermal alcohol monitoring devices (Mandated group) and some were not mandated (Non Mandated group). All wore a transdermal alcohol monitor during the 8-week study and were randomized to CM or a Control condition stratified by the mandate group. Participants completed weekly assessments of DRSE. Group-based trajectory-modeling identified three drinking behavior trajectory groups.

RESULTS

While there were no differences in baseline DRSE between the three trajectory groups, participants in the low- and moderate-frequency drinking behavior groups significantly increased DRSE across the study.

CONCLUSION

The present study indicates that being able to maintain abstinence or reduce heavy drinking may increase DRSE.

The externalizing and internalizing pathways to marijuana use initiation: Examining the synergistic effects of impulsiveness and sensation seeking

Adolescent marijuana use has become increasingly more problematic compared with the past; thus, understanding developmental processes that increase the liability of marijuana use is essential. Two developmental pathways to adolescent substance use have been proposed: an externalizing pathway that emphasizes the expression of aggressive and delinquent behavior, and an internalizing pathway that emphasizes the role of depressive symptoms and negative affect. In this study, we aimed to examine the synergistic role of impulsiveness and sensation seeking in the two risk pathways to determine whether both high and low levels of the traits are risk factors for marijuana use. Our study included 343 adolescents (52% were girls, 78% identified as Hispanic) that oversampled high-risk youth (78% had a family history of substance use disorder), assessed biannually between the ages of 13-16 years old. Moderated mediation analyses revealed that high levels of sensation seeking indirectly predicted marijuana use through higher mean levels of externalizing behavior. The positive relationship between sensation seeking and externalizing behavior was only significant at high levels of impulsiveness. Conversely, low levels of sensation seeking indirectly predicted marijuana use through higher mean levels of internalizing behavior. The negative relationship between sensation seeking and internalizing behavior was only significant at low levels of impulsiveness. Collectively, these results demonstrate that high and low levels of both impulsiveness and sensation seeking confer increased risk of marijuana use, albeit through different mechanisms. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The Development of Externalizing and Internalizing Behaviors Among Youth With or Without a Family History of Substance Use Disorder: The Indirect Effects of Early-Life Stress and Impulsivity

Youth with a family history of substance use disorder (FH+) are more prone to have externalizing and internalizing problems compared to youth without a family history of substance use disorder (FH-), increasing the likelihood of later maladjustment. However, mechanisms for this association remain understudied. In this longitudinal study, we examined if FH+ youth are more likely to experience early-life stressors (ELS), which in turn would increase impulsivity and the expression of externalizing and internalizing behaviors. Data were collected from youth and a parent (n = 386) during a baseline assessment (age 10-12 years) and every six months when the youth was 13-16 years old. In support of the primary hypothesis, FH+ youth reported higher levels of externalizing and internalizing behaviors through ELS to impulsivity providing a developmental pathway through which FH+ youth are more prone to externalizing and internalizing problems.

Social Support and the Rehabilitation of Alcohol-Impaired Drivers: Drinking Motives as Moderators

Alcohol-impaired driving is a common and costly public health problem associated with alcohol misuse. This investigation aims to understand the role of social support and drinking motives in motivating alcohol-impaired drivers to reduce alcohol use. One hundred nineteen participants with a history of driving-while-intoxicated arrest were recruited from either a correctional treatment facility (n = 59) or the community (n = 60) and asked about their motivation to change alcohol use. Motivation to change was tested in relationships with two types of social support (i.e. Abstinence-Specific Social Support and General Social Support) and drinking motives (Coping, Enhancement, and Social Motives). The results showed: (1) only Abstinence-Specific Social Support was positively associated with motivation to change; (2) Coping and Social Motives had a negative association with motivation to change; (3) the impact of Abstinence-Specific Social Support on motivation to change was greater among those with a stronger Enhancement Motives. In other words, those who drink primarily for pleasure showed a greater increase in motivation to change when more Abstinence-Specific Social Support is available, compared to those with lower Enhancement Motives. The findings of this investigation contribute to our knowledge of the roles of communication in the rehabilitation of alcohol-impaired drivers.

The Development of Impulsivity and Sensation Seeking: Associations with Substance Use among At-Risk Adolescents

We investigated if the dual systems model could explain the increased rates of substance use among at-risk youth. This study sampled 365 adolescents, 289 of which had a family history of substance use disorder, assessed biannually between the ages 13-16 years old. Growth curve analyses revealed that higher levels of impulsivity were related to higher levels of sensation seeking and a slower rate of decline in impulsivity was related to a faster rate of increase in sensation seeking. Only family history status and sensation seeking were directly associated with substance use (marijuana, alcohol) at age 16, though family history status was also indirectly related to substance use through higher levels of impulsivity to higher levels of sensation seeking.

Processing transdermal alcohol concentration (TAC) data to detect low-level drinking

BACKGROUND

Several studies have objectively quantified drinking through the use of Alcohol Monitoring System's (AMS) transdermal alcohol concentration (TAC) device known as SCRAM CAM. Criteria that AMS uses to detect drinking are known to be conservative and only reliably detect heavy drinking equivalent to 5 or more standard drinks. Our group has developed Research Rules used to process TAC data in a manner that will detect low-level and moderate drinking even though it is below the AMS criteria for detection.

METHODS

Sixteen male and 14 female paid research volunteers wore TAC monitors for 28 days in their natural environments and responded daily to text message prompts to self-report the previous day's drinking. Current analyses describe the Research Rules that we developed and how use of those rules impacts the detection of self-reported drinking treated as the standard in sensitivity/specificity analysis.

RESULTS

We observed 606 occurrences of positive TAC events over a total of 867 days and processed the TAC data to retain 345 as possible drinking events, even though AMS criteria confirmed drinking for only 163 of these events. The kinds of TAC events removed or retained by our rules are illustrated as cases of low and moderate drinking days that were detected by our rules but not by the conservative AMS criteria. AMS-confirmed TAC events have a high specificity (99.8%) to detect primarily heavy drinking, but have a poor sensitivity to detect lower-level drinking and a poor specificity as an indicator of alcohol abstinence. In contrast, our Research Rules detected 100% of TAC events detected by AMS but also detected 31% of the lower-level drinking events not detected by AMS, with 91% specificity.

CONCLUSIONS

Reliance upon the AMS criteria for alcohol detection affords a high specificity for detection of heavy drinking but is a poor indicator of abstinence rates. In contrast, use of our Research Rules provides more sensitive means to quantify either any drinking or low-moderate levels of drinking while still maintaining good specificity.

Estimating resource utilization demands in implementing statewide screening, brief intervention, and referral to treatment for alcohol-impaired drivers

OBJECTIVES

The Alcohol Use Disorders Identification Test (AUDIT) is used to assess the level of alcohol use/misuse and to inform the intensity of intervention delivered within screening, brief intervention, and referral to treatment (SBIRT) programs. Policy initiatives are recommending delivery of SBIRT within health care settings to reduce alcohol misuse and prevent alcohol-impaired driving. Recent reports are considering extending delivery of SBIRT to criminal justice settings. One consideration in implementing SBIRT delivery is the question of resource utilization; the amount of effort required in delivering the 4 different intensities of intervention in SBIRT: Alcohol education, simple advice, brief counseling and continued monitoring, and brief counseling and referral to specialist (from least to most intense in terms of delivery time, the skill level of the provider, and personnel resources).

METHODS

In order to inform expectations about intervention intensity, this article describes the AUDIT scores from 982 adults recently arrested for alcohol-impaired driving. The distribution of scores is extrapolated to state rates for individuals arrested for alcohol-impaired driving by intervention level.

RESULTS

Though alcohol education was the most common intervention category, about one quarter of the sample scored in a range corresponding with the more intensive interventions using the brief counseling, continued monitoring for ongoing alcohol use, and/or referral to specialist for diagnostic evaluation and treatment.

CONCLUSIONS

This article provides local distribution of AUDIT scores and state estimates for the number of individuals scoring in each level of risk (AUDIT risk zone) and corresponding intervention type. Routine criminal justice practice is well positioned to deliver alcohol screening, education, simple advice, and continued alcohol monitoring, making delivery of SBIRT feasible for the majority of alcohol-impaired drivers. Challenges to implementing the full range of SBIRT services include resource demands of brief counseling, identifying the appropriate providers within a criminal justice context, and availability of community providers for referral to diagnostic and specialty care. Solutions may vary by state due to differences in population density and incidence rates of alcohol-impaired driving.

The Role of Social Support in Motivating Reductions in Alcohol Use: A Test of Three Models of Social Support in Alcohol-Impaired Drivers

BACKGROUND

Social support has been linked to many therapeutic benefits (e.g., treatment retention, reduced posttreatment relapse) for individuals with alcohol use disorder. However, the positive impacts of social support have not been well understood in the context of alcohol-impaired driving. This article examines the role of social support in motivating those with histories of driving while intoxicated (DWI) arrest to reduce alcohol use by testing 3 major models of social support: the Main-Effects model, the Buffering model, and the Optimal Matching model.

METHODS

One hundred and nineteen participants with histories of DWI arrest were recruited from a correctional treatment facility (n = 59) and the local community (n = 60). Participants completed interviews to assess alcohol consumption, psychiatric/physical conditions, and psychosocial factors associated with drinking behavior (e.g., social support, alcohol-related problems, and motivation to change). Hierarchical regression analyses were conducted to test the 3 models. Additionally, the relative magnitude of the effects of general and recovery-specific social support was compared based on the approach of statistical inference of confidence intervals.

RESULTS

Overall social support was positively associated with some motivation to change (i.e., importance of change, confidence in change) among alcohol-impaired drivers, supporting the Main-Effects model. However, the impact of overall social support on motivation to change was not moderated by alcohol-related problems of individuals arrested for DWI, which did not confirm the Buffering model. Last, recovery-specific social support, rather than general social support, contributed to increasing motivation to reduce alcohol use, which supported the Optimal Matching model.

CONCLUSIONS

These findings highlight the benefits of social support (i.e., increased motivation to change alcohol use) for alcohol-impaired drivers. Regardless of the severity of alcohol-related problems of alcohol-impaired drivers, social support had direct positive impacts on motivation to change. In particular, the results underscore that social support can be more effective when it is matched to the recovery effort of individuals, which is consistent with the Optimal Matching model.

The correspondence between transdermal alcohol monitoring and daily self-reported alcohol consumption

Alcohol consumption is typically assessed via self-report methods, though there are concerns over the accuracy of this information. Transdermal alcohol monitoring can passively and continuously measure alcohol consumption with minimal interference in daily life. The current study examines the correspondence between daily self-reported alcohol consumption and transdermal alcohol monitors. Thirty-two healthy men (n = 16) and women (n = 16) wore a transdermal alcohol monitor for 28 days. Participants were instructed to drink as they usually do and prompted daily with a survey link to report yesterday's drinking. Data analyses focused on the following comparisons: (1) the overall correspondence between self-reported drinking and TAC readings; (2) the sensitivity of various TAC criteria thresholds to detect self-reported drinking (TAC thresholds of none, low, moderate, and heavy); and (3) the risks of false positive TAC findings using self-reported drinking as the Gold Standard. Participants self-reported drinking a total of 324 days, of which, TAC events were detected on 212 days (65.4%). When participants self-reported not drinking (399 days), zero TAC was also found on 366 days (92%). The correspondence between self-reported drinking and transdermal concentrations tended to be good: overall, when self-reported drinking was reported, TAC also detected drinking 65.4% of the time.

Pharmacokinetics of Phosphatidylethanol 16:0/20:4 in Human Blood After Alcohol Intake

BACKGROUND

The purpose of this study was to characterize the pharmacokinetics of the phosphatidylethanol (PEth) 16:0/20:4 homolog in uncoagulated human blood samples taken from 18 participants in a clinical laboratory setting after consumption of 2 standard doses of ethanol (EtOH).

METHODS

Male and female participants received either 0.4 or 0.8 g/kg oral doses of EtOH during a 15-minute period. Blood samples were collected before and throughout 6 hours immediately after alcohol administration and then again at days 2, 4, 7, 11, and 14 of the follow-up period. PEth 16:0/20:4 levels were quantified by high-performance liquid chromatography with tandem mass spectrometry detection.

RESULTS

(i) The increase in PEth 16:0/20:4 from baseline to maximum concentration was less than that of PEth 16:0/18:1 or PEth 16:0/18:2 homologs during the 6-hour period after EtOH administration; (ii) the mean half-life of PEth 16:0/20:4 was 2.1 ± 3 (SD) days, which was shorter than the mean half-life of either PEth 16:0/18:1 or PEth 16:0/18:2, 7.6 ± 3 (SD) or 6.8 ± 4 (SD) days, respectively.

CONCLUSIONS

The pharmacokinetics of PEth 16:0/20:4 in whole blood samples is detectable after alcohol consumption and differs in amount synthesized and rate of elimination versus PEth 16:0/18:1 and 16:0/18:2. Measuring the concentrations of these 3 homologs has the potential to provide more information about the amount and time frame of alcohol consumption than any one alone.

Translating transdermal alcohol monitoring procedures for contingency management among adults recently arrested for DWI

Recent developments in alcohol monitoring devices have made it more feasible to use contingency management (CM) procedures to reduce alcohol use. A growing body of literature is demonstrating the effectiveness of CM to reduce alcohol use among community recruited adults wearing transdermal alcohol concentration (TAC) monitoring devices. This article describes the quality improvement process aimed at adapting TAC-informed CM aimed at minimizing alcohol use and maximizing treatment completion. This extends literature to a high-risk population; adults arrested and awaiting trial (pretrial) for criminal charge of driving while intoxicated (DWI). Participants were enrolled during their orientation to pretrial supervision conditions of DWI bond release. At enrollment, participants completed a screening, brief intervention, and referral to treatment; those with high risk alcohol histories were enrolled in an 8-week CM procedure to avoid TAC readings. Four Plan-Do-Study-Act (PDSA) quality improvement cycles were conducted where the TAC cutoff for determining alcohol use, the quantity of reinforcer, and handling of tampers on the transdermal alcohol monitor were manipulated. Across four PDSA cycles, the retention for the full 8-weeks of treatment was increased. The proportion of weeks with alcohol use was not decreased across cycles, the peak TAC values observed during drinking weeks were significantly lower in Cycles 1 and 4 than 3. CM may be developed as a tool for pretrial supervision to be used to increase bond compliance of those arrested for DWI and for others as a method to identify the need for additional judicial services.

Differences in the Synthesis and Elimination of Phosphatidylethanol 16:0/18:1 and 16:0/18:2 After Acute Doses of Alcohol

BACKGROUND

The purpose of this study was to examine the synthesis and elimination of phosphatidylethanol (PEth) 16:0/18:1 and 16:0/18:2 following the consumption of alcohol among 56 light and heavy drinkers.

METHODS

A transdermal alcohol monitor was used to promote alcohol absence 7 days prior, and 14 days after, alcohol consumption in the laboratory. Participants consumed a 0.4 or 0.8 g/kg dose of alcohol in 15 minutes. Blood and breath samples were collected before, at various times up to 360 minutes postconsumption, and 2, 4, 7, 11, and 14 days after alcohol consumption. Initial rates of PEth synthesis, 360 minutes area under the PEth pharmacokinetic curves (AUCs), and elimination half-lives were determined.

RESULTS

(i) Nonzero PEth levels were observed before alcohol dosing for most participants, despite 7 days of alcohol use monitoring; (ii) 0.4 and 0.8 g/kg doses of alcohol produced proportional increases in PEth levels in all but 1 participant; (iii) the initial rate of synthesis of both PEth homologues did not differ between the 2 doses, but was greater for PEth 16:0/18:2 than PEth 16:0/18:1 at both doses; (iv) the mean AUC of both PEth homologues was higher at 0.8 g/kg than at 0.4 g/kg; (v) the mean AUC of 16:0/18:2 was greater than that of PEth 16:0/18:1 at both alcohol doses; (vi) the mean half-life of PEth 16:0/18:1 was longer than that of PEth 16:0/18:2 (7.8 ± 3.3 [SD] days and 6.4 ± 5.0 [SD] days, respectively); and (vii) there were no sex differences in PEth 16:0/18:1 or 16:0/18:2 pharmacokinetics.

CONCLUSIONS

The results of this study support the use of PEth 16:0/18:1 and 16:0/18:2 as biomarkers for alcohol consumption. Because of consistent pharmacokinetic differences, the levels of these 2 PEth homologues may provide more information regarding the quantity and recentness of alcohol consumption than either alone.

Rationale and design of a pilot study examining Acceptance and Commitment Therapy for persistent pain in an integrated primary care clinic

Most of the 100 million Americans with persistent pain are treated in primary care clinics, but evidence-based psychosocial approaches targeting pain-related disability are not usually provided in these settings. This manuscript describes the rationale and methods for a protocol to pilot test the feasibility and effectiveness of Acceptance and Commitment Therapy (ACT), an evidence-based psychological treatment for persistent pain, delivered by a Behavioral Health Consultant in primary care. Eligible patients are identified through electronic health record registries and invited to participate via secure messaging, letters and a follow-up phone call. Participants are also recruited with advertising and clinician referral. Patients agreeing to participate are consented and complete initial assessments, with a target of 60 participants. Randomization is stratified based on pain severity with participants assigned to either ACT or Enhanced Treatment as Usual (E-TAU). ACT participants receive one standardized Behavioral Health Consultation visit followed by three ACT-based group visits and one group booster visit. All patients attend six assessment visits, during which the E-TAU patients are provided with educational pain management handouts based on standard cognitive behavioral treatment of pain. The study aims to determine feasibility and effectiveness of brief ACT for persistent pain delivered by an integrated behavioral health clinician in primary care from pre- to post-treatment, and to examine mechanisms of change in ACT participants. This study, in a "real-world" setting, will lay groundwork for a larger trial. If effective, it could improve treatment methods and quality of life for patients with persistent pain using a scalable approach.

A test of the psychometric characteristics of the BIS-Brief among three groups of youth

The Barratt Impulsiveness Scale (BIS-11) is the most widely administered trait impulsiveness questionnaire. Recently a shorter, unidimensional version of the instrument was developed for adults (BIS-Brief). While psychometric characteristics of the BIS-Brief support its use among adults, it also may be more appropriate for youth samples than the complete BIS-11 because it less burdensome and omits items about activities not usually encountered by children and adolescents. This article describes a test of psychometric characteristics of the BIS-Brief among youth. To measure a sufficiently wide range of scores, analyses were conducted based on secondary data analysis of data sets pooled from 3 distinct youth cohorts aged 10-17: healthy controls (Control; n = 356); those who had a family history of substance use disorder (FH+; n = 302); and psychiatric inpatients (Patients; n = 322). Model fit for the BIS-Brief was good but varied somewhat depending on the respondent cohort. There was a strong correlation between test and re-test BIS-Brief both within a single day and at 6 months, and also a strong correlation between BIS-Brief and BIS-11 scores. Concurrent validity was supported by correlation with questionnaire measures, which tended to be more robustly associated with BIS-Brief than behavioral measures. Both BIS-Brief and BIS-11 forms were similarly associated with other convergent measures. In conclusion, the BIS-Brief is a shorter version of the BIS-11 that reduces participant burden and with psychometric properties that support its use among youth populations. (PsycINFO Database Record

Preadolescent sensation seeking and early adolescent stress relate to at-risk adolescents' substance use by age 15

BACKGROUND AND AIMS

Substance use during adolescence can lead to the development of substance use disorders and other psychosocial problems. These negative outcomes are especially likely for individuals who use substances at earlier ages and those who engage in heavier use during adolescence, behaviors which are both more common among youth at higher risk for developing a substance use disorder, such as those with a family history of substance use disorders (FH+). Factors such as increased sensation seeking and greater exposure to stressors among FH+ youth may influence these associations. Therefore, the aim of this study was to examine the relative and unique contributions of sensation seeking during preadolescence and exposure to stressors during early to mid-adolescence to cumulative substance use by mid-adolescence among FH+ youth.

METHODS

A total of 167 mostly Hispanic FH+ youth (ages 12-15) who were participating in an ongoing longitudinal study were included in these analyses. Participants' data from biennial waves covering approximately 2.5years were used. Self-reported sensation seeking, exposure to stressors, and substance use were compared.

RESULTS

Higher sensation seeking during preadolescence and greater exposure to stressors during early to mid-adolescence were both associated with substance use by age 15. These factors differentiated Substance Users from Non-Users, and also related to level of substance use.

CONCLUSIONS

Elevated sensation seeking and exposure to stressors are both associated with substance use by age 15 among high-risk youth. Additionally, these factors can distinguish youth who develop heavier substance use during this important developmental period.

Reproducibility of tract-based white matter microstructural measures using the ENIGMA-DTI protocol

BACKGROUND

In preparation for longitudinal analyses of white matter development in youths with family histories of substance use disorders (FH+) or without such histories (FH-), we examined the reproducibility and reliability of global and regional measures of fractional anisotropy (FA) values, measured using the Enhancing Neuro Imaging Genetics Through Meta Analysis (ENIGMA)-diffusion tensor imaging (DTI) protocol. Highly reliable measures are necessary to detect any subtle differences in brain development.

METHODS

First, we analyzed reproducibility data in a sample of 12 healthy young adults (ages 20-28) imaged three times within a week. Next, we calculated the same metrics in data collected 1-year apart in the sample of 68 FH+ and 21 FH- adolescents. This is a timeframe where within subject changes in white matter microstructure are small compared to between subject variance. Reproducibility was estimated by examining mean coefficients of variation (MCV), mean absolute differences (MAD), and intraclass correlations (ICC) for global and tract-specific FA values.

RESULTS

We found excellent reproducibility for whole-brain DTI-FA values and most of the white matter tracts, except for the corticospinal tract and the fornix in both adults and youths. There was no significant effect of FH-group on reproducibility (p = .4). Reproducibility metrics were not significantly different between adolescents and adults (all p > .2). In post hoc analyses, the reproducibility metrics for regional FA values showed a strong positive correlation (r = .6) with the regional FA heritability measures previously reported by ENIGMA-DTI.

CONCLUSION

Overall, this study demonstrated an excellent reproducibility of ENIGMA-DTI FA, positing it as viable analysis tools for longitudinal studies and other protocols that repeatedly assess white matter microstructure.

Acute effects of methylphenidate on impulsivity and attentional behavior among adolescents comorbid for ADHD and conduct disorder

Adolescents with Attention Deficit Hyperactivity Disorder (ADHD) and Conduct Disorder (CD) experience deficits in neuropsychological measures of attention, inhibition, and reward processes. Methylphenidate treatment for ADHD and CD has acute effects on these processes. Some of these same aspects of performance are separately described in the Behavioral Model of Impulsivity, which uses a modified approach to measurement. This study characterized the acute effects of methylphenidate attention, initiation, inhibition, and reward processes described in this model of impulsivity. Thirty-one adolescents from the United States of America with comorbid ADHD and CD completed measures of impulsivity (response initiation, response inhibition, and consequence) and attention following placebo, 20 mg, and 40 mg of a long-acting dose of methylphenidate. Methylphenidate effects on attentional performance was more robust than on any of the measures of impulsivity. Adolescent performance from this behavioral perspective is interpreted in the context of divergence from previous neuropsychological tests of acute methylphenidate effects.

Early Adolescent Trajectories of Impulsiveness and Sensation Seeking in Children of Fathers with Histories of Alcohol and Other Substance Use Disorders

BACKGROUND

Problem substance use often begins in adolescence. This vulnerability likely stems, at least partially, from relatively rapid increases in sensation seeking occurring in early to mid-adolescence and more gradual improvements in impulse control occurring through later adolescence. Better understanding how these processes develop in high-risk youth may lead to enhanced substance use disorder treatment and prevention strategies.

METHODS

We characterized trajectories of self-reported impulsivity and sensation seeking in 305 FH+ youths who at minimum had a father with a history of alcohol or other drug use disorders and 81 youths with no family histories of substance use disorders (FH-). Assessments started at ages 10 to 12 and continued at 6-month intervals for up to 42 months. In addition, a subset of 58 FH+ youths who began alcohol or other drug use before age 15 (FH+ Users) were compared to 58 FH+ propensity-matched adolescents who did not initiate substance use before age 15 (FH+ Non-Users).

RESULTS

Compared to FH- youths at preadolescence, FH+ youths reported higher general impulsivity and higher impulsivity related to poor planning and attention. Over time, there were no differential effects of FH status on changes in impulsivity or sensation seeking across adolescence. FH+ Users had smaller decreases in general impulsivity and impulsivity related to restlessness and fidgeting across adolescence than FH+ Non-Users. FH+ Users also had greater increases in sensation seeking across adolescence than FH+ Non-Users.

CONCLUSIONS

Increased impulsivity in FH+ youths may make them less able to regulate sensation seeking drives that peak in adolescence, which may contribute to their high risk for developing substance use disorders. Additionally, FH+ adolescents who initiate early use may be at increased risk in part due to increased impulsivity coupled with greater increases in sensation seeking.

Altered developmental trajectories for impulsivity and sensation seeking among adolescent substance users

A number of studies have associated impulsivity and sensation seeking with level of substance use and risk for developing a substance use disorder. These relationships may be particularly apparent during adolescence, when developmental changes in impulsivity and sensation seeking occur at the same time as increased opportunities for substance use. To examine this, the current study measured impulsivity and sensation seeking from pre-adolescence to mid-adolescence in a sample of youth, the majority of whom were identified as being at risk for developing a substance use disorder based on their family history of substance use disorders. Youth were separated into those who did (n=117) and did not (n=269) initiate substance use by mid-adolescence. Results showed that substance users were more impulsive and more sensation seeking during pre-adolescence, prior to any significant substance use, and that greater sensation seeking in pre-adolescence was related to heavier substance use by mid-adolescence. In addition, developmental trajectories for substance-using youth showed a greater increase in sensation seeking but a more modest decrease in impulsivity from pre-adolescence to mid-adolescence. Taken together, these results indicate that increased impulsivity and sensation seeking is apparent in adolescent substance users as early as pre-adolescence, that the difference between substance users and non-users becomes larger across early adolescence as their developmental trajectories diverge, and that greater sensation seeking in pre-adolescence may predict increased substance use by mid-adolescence.

Child Problems as a Moderator of Relations Between Maternal Impulsivity and Family Environment in a High-Risk Sample

OBJECTIVE

Previous studies have suggested that maternal characteristics are related to family environment; however, the relation between maternal impulsivity, in particular, and family environment is not well understood. As such, we examined direct relations between maternal impulsivity and family environment, as well as whether the relation between maternal impulsivity and family environment was moderated by child problems for sons and daughters. We hypothesized that child problems would moderate the association between maternal impulsivity and family environment. We also explored whether these associations differ for boys and girls.

METHOD

Data from the initial visit of a longitudinal study was used for the current study. Participants included 297 youth (137 boys; 160 girls) of 10 to 12 years of age (M = 10.99, SD = .84) and their mothers. The majority of the sample had a family history of substance use disorder (n = 236).

RESULTS

Hierarchical linear regressions showed that for sons there was a significant interaction between maternal impulsivity and child problems on family environment. Maternal impulsivity was positively related to family environment problems among sons with few emotional and behavioral problems, but there was no significant correlation among sons with high problem levels. Among daughters, there was no significant interaction between maternal impulsivity and child emotional and behavioral problems on family environment.

CONCLUSIONS

The results suggest that the association between maternal impulsivity and family environment may depend on problem level and child gender. Thus, addressing maternal impulsivity in therapy may benefit some families.

Time Delays in Transdermal Alcohol Concentrations Relative to Breath Alcohol Concentrations

AIMS

Monitors of transdermal alcohol concentration (TAC) provide an objective measurement of alcohol consumption that is less invasive than measurements in blood, breath or urine; however, there is a substantial time delay in the onset of TAC compared to blood or breath alcohol concentrations (BrACs). The current study examined the characteristics of the delay between peak TAC and peak BrAC.

METHODS

Data was aggregated from three experimental laboratory studies (N = 61; 32 men, 29 women) in which participants wore a TAC monitor and BrAC was monitored while drinking one, two, three, four and five beers in the laboratory. Analyses examined the sex- and dose-related differences in peak BrAC and TAC, the time-to-peak BrAC and TAC, and time lag between the peak BrAC and TAC values.

RESULTS

The times-to-peak were an increasing function of the number of beers consumed. At each level of beer consumption the peak TAC averaged lower than peak BrAC and times-to-peak TAC were longer than for BrAC. The time-to-peak BrAC and TAC was longer for women than men. The congruence between peak TAC and BrAC increased as a function of the beers consumed. No sex difference in the time lag between peak BrAC and TAC was detected.

CONCLUSIONS

The congruence between TAC and BrAC and time lags between TAC and BrAC are related to the number of beers consumed. Peak values of TAC and BrAC became more congruent with higher doses but the time lag increased as a function of the amount of alcohol consumed.

SHORT SUMMARY

The time delay (or lag) and congruence between transdermal vs. BrACs increases as the number of beers increases. Though sex differences are evident in peak transdermal and BrACs, no sex differences were evident in the time lag and the congruence between transdermal and breath alcohol concentrations.

Assessment of the Human Kynurenine Pathway: Comparisons and Clinical Implications of Ethnic and Gender Differences in Plasma Tryptophan, Kynurenine Metabolites, and Enzyme Expressions at Baseline and After Acute Tryptophan Loading and Depletion

Tryptophan (Trp) metabolism via the kynurenine pathway (KP) was assessed in normal healthy US volunteers at baseline and after acute Trp depletion (ATD) and acute Trp loading (ATL) using amino acid formulations. The hepatic KP accounts for ~90% of overall Trp degradation. Liver Trp 2,3-dioxygenase (TDO) contributes ~70% toward Trp oxidation, with the remainder achieved by subsequent rate-limiting enzymes in the KP. TDO is not influenced by a 1.15 g Trp load, but is maximally activated by a 5.15 g dose. We recommend a 30 mg/kg dose for future ATL studies. ATD activates TDO and enhances the Trp flux down the KP via its leucine component. Higher plasma free [Trp] and lower total [Trp] are observed in women, with no gender differences in kynurenines. Kynurenic acid is lower in female Caucasians, which may explain their lower incidence of schizophrenia. African-American and Hispanic women have a lower TDO and Trp oxidation relative to free Trp than the corresponding men. African-American women have a potentially higher 3-hydroxyanthranilic acid/anthranilic acid ratio, which may protect them against osteoporosis. Future studies of the KP in relation to health and disease should focus on gender and ethnic differences.

Pubertal Maturation Compression and Behavioral Impulsivity among Boys at Increased Risk for Substance Use

OBJECTIVES

While early onset of puberty among girls has been related to substance use involvement and other adverse outcomes, less research has examined pubertal development and outcomes in boys. Further, research on puberty has not been conducted in the context of other risk factors for substance use involvement such as impulsivity. To address these gaps, this study characterized boys' pubertal development from preadolescence to mid-adolescence and related it to substance use risk and behavioral impulsivity.

METHODS

A sample of 153 boys completed the Pubertal Development Scale to assess perception of their pubertal development relative to same age peers from ages 10 to 16 years, at 6-month intervals. Group-based trajectory modeling identified three distinct patterns of pubertal development: boys with more slowly developing boys with either earlier (n = 54) or later (n = 43) pubertal timing, and boys with faster tempo of pubertal development (n = 56). The groups were compared on demographic and substance use risk characteristics, as well as behavioral measures of impulsivity.

RESULTS

Boys who had the accelerated progression through puberty had the highest proportion of family histories of substance use disorder and perform more impulsively on reward choice measures.

CONCLUSIONS

Outcomes are consistent within the Maturation Compression Hypothesis and social neuroscience models of adolescent developmental risk.

Clinical and Social/Environmental Characteristics in a Community Sample of Children With and Without Family Histories of Substance Use Disorder in the San Antonio Area: A Descriptive Study

This is a descriptive study of the recruitment and clinical/environmental characteristics of a child cohort (ages 10-12) established to test transmission of impulsivity in children with (FH+; n = 305) and without (FH-; n = 81) family history of substance use disorder. Among this cohort FH⁺ children had more emotional and behavioral symptoms, worse family relationships, and more deviant peers compared to FH^- children. This cohort of children was established prior to the initiation of regular substance use and significant clinical problems, which will allow the opportunity to examine reciprocal relations between development of impulse control and substance use development.

Characterization of the Pharmacokinetics of Phosphatidylethanol 16:0/18:1 and 16:0/18:2 in Human Whole Blood After Alcohol Consumption in a Clinical Laboratory Study

BACKGROUND

The purpose of this study was to characterize the pharmacokinetics of 2 homologues of phosphatidylethanol (PEth) and their combined total in uncoagulated, whole blood samples taken from participants in a human clinical laboratory study after consumption of low doses of ethanol (EtOH).

METHODS

As part of a larger study, 14 male and 13 female participants received either 0.25 or 0.50 g/kg oral doses of EtOH during a 15-minute period. Blood samples were collected before and throughout 6 hours after each EtOH dose on the day of consumption and then every 3 days during the next 14 days. PEth 16:0/18:1 and PEth 16:0/18:2 levels were quantified in blood samples by HPLC/MS/MS and reported separately or as their combined total (combined PEth). Breath alcohol concentrations (BrACs) were measured concurrently with each blood collection. Transdermal alcohol concentrations were measured every 30 minutes during the entire 22-day study to confirm the absence of drinking during a 7-day period before and the 14-day period after EtOH consumption.

RESULTS

(i) Single doses of 0.25 and 0.50 g EtOH/kg produced proportional increases in BrAC and combined PEth levels of all participants; (ii) the areas under the curve (AUCs) for each participant's BrAC levels during the 6-hour period after EtOH administration were correlated with AUCs of cPEth (calculated as the AUC of the increase above baseline for combined PEth); (iii) the mean half-life of combined PEth, determined during the 14-day period after EtOH consumption, was 4.6 ± 3.5 (SD) days (range: 1.0 to 13.1 days).

CONCLUSIONS

Combined PEth is a sensitive biomarker for the identification of relatively low levels of EtOH consumption. The measurement of these 2 homologues may provide additional sensitivity to identify low levels of drinking.

Using contingency management procedures to reduce at-risk drinking in heavy drinkers

BACKGROUND

Treatments for alcohol use disorders typically have been abstinence based, but harm reduction approaches that encourage drinkers to alter their drinking behavior to reduce the probability of alcohol-related consequences, have gained in popularity. This study used a contingency management procedure to determine its effectiveness in reducing alcohol consumption among heavy drinkers.

METHODS

Eighty-two nontreatment-seeking heavy drinkers (ages 21 to 54, M = 30.20) who did not meet diagnostic criteria for alcohol dependence participated in the study. The study had 3 phases: (i) an Observation phase (4 weeks) where participants drank normally; (ii) a Contingency Management phase (12 weeks) where participants were paid $50 weekly for not exceeding low levels of alcohol consumption as measured by transdermal alcohol concentrations, <0.03 g/dl; and (iii) a Follow-up phase (12 weeks) where participants (n = 66) returned monthly for 3 months to self-report drinking after the contingencies were removed. Transdermal alcohol monitors were used to verify meeting contingency requirements; all other analyses were conducted on self-reported alcohol use.

RESULTS

On average 42.3% of participants met the contingency criteria and were paid an average of $222 during the Contingency Management phase, with an average $1,998 in total compensation throughout the study. Compared to the Observation phase, the percent of any self-reported drinking days significantly decreased from 59.9 to 40.0% in the Contingency Management and 32.0% in the Follow-up phases. The percent of self-reported heavy drinking days reported also significantly decreased from 42.4% in the Observation phase to 19.7% in the Contingency Management phase, which was accompanied by a significant increase in percent days of self-reported no (from 40.1 to 60.0%) and low-level drinking (from 9.9 to 15.4%). Self-reported reductions in drinking either persisted, or became more pronounced, during the Follow-up phase.

CONCLUSIONS

Contingency management was associated with a reduction in self-reported episodes of heavy drinking among nontreatment-seeking heavy drinkers. These effects persisted even after incentives were removed, indicating the potential utility of contingency management as a therapeutic intervention to reduce harmful patterns of drinking.

Feasibility of a computer-assisted alcohol screening, brief intervention and referral to treatment program for DWI offenders

BACKGROUND

Alcohol use patterns that are hazardous for one's health is prevalent among DWI (driving while intoxicated) offenders and is a key predictor of recidivism. The aim of this program evaluation was to determine the feasibility and usability of implementing a computer-assisted screening, brief intervention and referral to treatment (SBIRT) program for DWI offenders to enable the identification of those in need of treatment services soon after arrest. Our treatment program consisted of a web-based, self-guided screening tool for assessing alcohol use patterns and generating a personalized feedback report that is then used to deliver a brief motivational intervention and if needed, a referral to treatment.

METHODS

Between August and November 2014, all DWI offenders attending orientation for pre-trial supervision were assessed for eligibility. Of the 129 eligible offenders, 53.5 percent enrolled and the first 50 were asked to complete a usability and satisfaction questionnaire.

RESULTS

The results demonstrated that the majority of those screened reported at-risk alcohol use patterns requiring referral to treatment. Clients reported high ratings of usability and satisfaction with the screening tool and personalized feedback report, which did not significantly differ depending on alcohol use patterns. There were relatively few technical difficulties, and the majority of clients reported high levels of satisfaction with the overall SBIRT program.

CONCLUSION

Results of this program evaluation suggest that computer-assisted SBIRT may be successfully implemented within the criminal justice system to DWI offenders soon after arrest; however, further research is required to examine its effects on treatment utilization and recidivism.

Increased Pre- and Early-Adolescent Stress in Youth with a Family History of Substance Use Disorder and Early Substance Use Initiation

Individuals with a family history of substance use disorders (Family History Positive) are more likely to have early-onset substance use (i.e., prior to age 15), which may contribute to their higher rates of substance use disorders. One factor that may differentiate Family History Positive youth who engage in early-onset substance use from other Family History Positive youth is exposure to stressors. The aim of this study was to quantify how exposure to stressors from age 11-15 varies as a function of family history of substance use disorders and early-onset substance use. Self-reported stressors were prospectively compared in a sample of predominately (78.9%) Hispanic youth that included 68 Family History Positive youth (50% female) who initiated substance use by age 15 and demographically matched non-users with (n = 136; 52.9% female) and without (n = 75; 54.7% female) family histories of substance use disorders. Stressors were assessed at 6-month intervals for up to 4 years. Both the severity of stressors and the degree to which stressors were caused by an individual's own behavior were evaluated. All three groups differed from one another in overall exposure to stressors and rates of increase in stressors over time, with Family History Positive youth who engaged in early-onset substance use reporting the greatest exposure to stressors. Group differences were more pronounced for stressors caused by the participants' behavior. Family History Positive users had higher cumulative severity of stressors of this type, both overall and across time. These results indicate greater exposure to stressors among Family History Positive youth with early-onset substance use, and suggest that higher rates of behavior-dependent stressors may be particularly related to early-onset use.

Behavioral Impulsivity and Risk-Taking Trajectories Across Early Adolescence in Youths With and Without Family Histories of Alcohol and Other Drug Use Disorders

BACKGROUND

Youths with family histories of alcohol and other drug use disorders (FH+) are at increased susceptibility for developing substance use disorders relative to those without such histories (FH-). This vulnerability may be related to impaired adolescent development of impulse control and elevated risk-taking. However, no previous studies have prospectively examined impulse control and risk-taking in FH+ youth across adolescence.

METHODS

A total of 386 pre-adolescents (305 FH+, 81 FH-; aged 10 to 12) with no histories of regular alcohol or other drug use were compared on behavioral measures of impulsivity including delay discounting, response initiation (Immediate Memory Task), response inhibition impulsivity (GoStop Impulsivity Paradigm), and risk-taking (Balloon Analogue Risk Task-Youth). Youths completed these laboratory tasks every 6 months, allowing for the examination of 10- to 15-year-olds. Hierarchical linear modeling was used to characterize the development of impulse control and risk-taking as shown in performance of these tasks throughout adolescence.

RESULTS

We found that (i) FH+ youths had increased levels of delay discounting and response inhibition impulsivity at study entry; (ii) regardless of FH status, all youths had relatively stable delay discounting across time, improvements in response inhibition and response initiation impulsivity, and increased risk-taking; and (iii) although FH+ youths had increased response inhibition impulsivity at pre-adolescence, these differences were negligible by mid-adolescence.

CONCLUSIONS

Heightened delay discounting in FH+ pre-adolescents coupled with normal adolescent increases in risk-taking may contribute to their increased susceptibility toward problem substance use in adolescence.

Behavioral Impulsivity and Risk-Taking Trajectories Across Early Adolescence in Youths With and Without Family Histories of Alcohol and Other Drug Use Disorders

BACKGROUND

Youths with family histories of alcohol and other drug use disorders (FH+) are at increased susceptibility for developing substance use disorders relative to those without such histories (FH-). This vulnerability may be related to impaired adolescent development of impulse control and elevated risk-taking. However, no previous studies have prospectively examined impulse control and risk-taking in FH+ youth across adolescence.

METHODS

A total of 386 pre-adolescents (305 FH+, 81 FH-; aged 10 to 12) with no histories of regular alcohol or other drug use were compared on behavioral measures of impulsivity including delay discounting, response initiation (Immediate Memory Task), response inhibition impulsivity (GoStop Impulsivity Paradigm), and risk-taking (Balloon Analogue Risk Task-Youth). Youths completed these laboratory tasks every 6 months, allowing for the examination of 10- to 15-year-olds. Hierarchical linear modeling was used to characterize the development of impulse control and risk-taking as shown in performance of these tasks throughout adolescence.

RESULTS

We found that (i) FH+ youths had increased levels of delay discounting and response inhibition impulsivity at study entry; (ii) regardless of FH status, all youths had relatively stable delay discounting across time, improvements in response inhibition and response initiation impulsivity, and increased risk-taking; and (iii) although FH+ youths had increased response inhibition impulsivity at pre-adolescence, these differences were negligible by mid-adolescence.

CONCLUSIONS

Heightened delay discounting in FH+ pre-adolescents coupled with normal adolescent increases in risk-taking may contribute to their increased susceptibility toward problem substance use in adolescence.

Striatal activity and reduced white matter increase frontal activity in youths with family histories of alcohol and other substance-use disorders performing a go/no-go task

INTRODUCTION

Youths with a family history of alcohol and other drug use disorders (FH+) are at greater risk of developing substance-use disorders relative to those with no such family histories (FH-). We previously reported that FH+ youths have elevated activity in the supplementary motor area (SMA) and dorsal striatum while performing go/no-go tasks and have reduced frontal white matter integrity. A better understanding of relationships between these variables would provide insight into how frontostriatal circuitry is altered in FH+ youths, which may be an important contributor to their elevated risk.

METHODS

In this study, we used structural equation modeling (SEM) to test interactions between activity in the SMA and dorsal striatum in 72 FH+ and 32 FH- youths during go/no-go task performance and to determine whether increased activity in these regions in FH+ youths can be at least partially explained by reduced frontal white matter integrity, as indexed by anterior corona radiata fractional anisotropy and N-acetylaspartate.

RESULTS

Increased dorsal striatum activity explained most (∽75%) of the elevated SMA activity in FH+ youths, and the combined contributions of increased dorsal striatal activity, and decreased white matter integrity fully explained the elevated SMA activity.

CONCLUSIONS

These results suggest the elevated frontal cortical activity in FH+ youths is driven both by their increased striatal activity via downstream projections and reduced white matter integrity in frontal cortical projections, the latter likely increasing frontal cortical activity due to increased energy demands required for action potential propagation. As part of our ongoing longitudinal studies we will examine how these frontostriatal alterations relate to risk for developing substance-use disorders.

Using Transdermal Alcohol Monitoring to Detect Low-Level Drinking

BACKGROUND

Several studies demonstrate the utility of Alcohol Monitoring Systems' (AMS) transdermal alcohol concentration (TAC) monitor to objectively quantify drinking. AMS standard criteria (i.e., TAC >0.02 g/dl) used for drinking detection are deliberately conservative, but consequently only detect drinking equivalent to 5 or more standard drinks. Our study sought to characterize the sensitivity of TAC measurement to detect low-level drinking defined as the consumption of 1 to 3 beers.

METHODS

Data were pooled from 3 studies giving controlled doses of 1, 2, 3, 4, and 5 Corona© beers (12 oz = 0.92 standard units) to 32 male and 29 female research volunteers wearing TAC monitors under controlled conditions. Analyses describe the sensitivity to detect drinking at various peak TAC thresholds beginning with any positive reading >0 g/dl, and then using TAC thresholds of 0.02 and 0.03 g/dl.

RESULTS

Nearly 40% of participants drinking 1 beer did not have a positive TAC reading. However, positive TAC readings were observed in more than 95 and in 100% of participants drinking 2 and 3 or more beers, respectively. The probability of peak TAC detection was a positive function of the number of beers consumed and a negative function of the minimum TAC threshold for detection. Drinking was somewhat more likely to be detected in females than males drinking 2 to 5 beers, but not after 1 beer. Use of AMS standard criteria only reliably detected the consumption of 5 beers, and 45.9% of all occasions of drinking 1 to 3 beers were undetected using 0.02 g/dl as a threshold.

CONCLUSIONS

Peak TAC levels between 0 and 0.02 g/dl must be considered to detect the low-level drinking of 1 to 3 standard drinks, and such thresholds are necessary when researchers and clinicians want to detect low-level drinking.

Standardization of formulations for the acute amino acid depletion and loading tests

The acute tryptophan depletion and loading and the acute tyrosine plus phenylalanine depletion tests are powerful tools for studying the roles of cerebral monoamines in behaviour and symptoms related to various disorders. The tests use either amino acid mixtures or proteins. Current amino acid mixtures lack specificity in humans, but not in rodents, because of the faster disposal of branched-chain amino acids (BCAAs) by the latter. The high content of BCAA (30-60%) is responsible for the poor specificity in humans and we recommend, in a 50g dose, a control formulation with a lowered BCAA content (18%) as a common control for the above tests. With protein-based formulations, α-lactalbumin is specific for acute tryptophan loading, whereas gelatine is only partially effective for acute tryptophan depletion. We recommend the use of the whey protein fraction glycomacropeptide as an alternative protein. Its BCAA content is ideal for specificity and the absence of tryptophan, tyrosine and phenylalanine render it suitable as a template for seven formulations (separate and combined depletion or loading and a truly balanced control). We invite the research community to participate in standardization of the depletion and loading methodologies by using our recommended amino acid formulation and developing those based on glycomacropeptide.

Effects of tryptophan depletion and a simulated alcohol binge on impulsivity

Researchers have suggested binge drinkers experience disproportionate increases in impulsivity during the initial period of drinking, leading to a loss of control over further drinking, and that serotonergic mechanisms may underlie such effects. We examined the effects of a simulated alcohol binge and tryptophan depletion on 3 types of impulsivity-response initiation (immediate memory task [IMT]), response inhibition (GoStop task), and delay discounting (single key impulsivity paradigm [SKIP])-and tested whether observed effects were related to real-world binging. Adults (N = 179) with diverse drinking histories completed a within-subject crossover design over 4 experimental days. Each day, participants underwent 1 of 4 test conditions: tryptophan depletion/alcohol, tryptophan depletion/placebo, tryptophan-balanced control/alcohol, or tryptophan-balanced control/placebo. The simulated binge involved consuming 0.3 g/kg of alcohol at 5, 6, and 7 hr after consuming the tryptophan-depletion/balanced mixture. Impulsivity was measured before and after each drink. Relative to the placebo beverage condition, when alcohol was consumed, impulsive responding was increased at moderate and high levels of intoxication on the IMT and the GoStop but only at high levels of intoxication on the SKIP. Tryptophan depletion had no effect on impulsivity. Effects of alcohol and tryptophan manipulations on impulsivity were unrelated to patterns of binge drinking outside the laboratory. The effects of alcohol consumption on impulsivity depend on the component of impulsivity and the dose of alcohol consumed. Such effects do not appear to be a result of reduced serotonin synthesis. In addition, real-world binge drinking behaviors were unrelated to behavioral changes observed in the laboratory.

Assessing the Validity of Participant-Derived Compared to Staff-Derived Values to Compute a Binge Score

AIMS

This study examined the validity of two methods of classifying binge drinkers.

METHODS

Adult drinkers (n = 166) completed the Alcohol Use Questionnaire (AUQ) and a Timeline Followback (TLFB) interview to characterize drinking during the past 28 days. Using Townshend and Duka's (2005) recommendations, answers on three AUQ items (average drinks per hour, number of times drunk within the prior 6 months and percentage of times drunk when drinking) were used to derive a binge score that was then used to classify drinkers as Binge, Non-Binge and Unclassifiable. Two methods for calculating binge scores were compared: (a) Participant-derived, using participants' answers on the 3 AUQ items; and (b) Staff-derived, staff used TLFB interview information to answer the 3 AUQ items. Additionally, Participant- and Staff-derived classifications were used to predict future drinking behaviors assessed by a second TLFB interview.

RESULTS

Participant- and Staff-derived binge scores had a low concordance rate. Staff-derived classifications were better than Participant-derived classifications at predicting future binge drinking behavior and identifying group differences in drinking behavior reported during the second TLFB interview (average drinks per hour, number of times drunk within the prior 6 months, and percentage of times drunk when drinking).

CONCLUSIONS

Classifying drinkers using staff-guided TLFB interview methods instead of self-reported participant generalizations of typical drinking habits better relates to real-world drinking. Classification schemes that rely on dichotomous categorization of drinkers (Binge vs. Non-Binge) may be missing individuals who engage in harmful patterns of drinking. A continuous scale or index characterizing problematic drinking may be more useful.

Transdermal alcohol concentration data collected during a contingency management program to reduce at-risk drinking

BACKGROUND

Recently, we demonstrated that transdermal alcohol monitors could be used in a contingency management procedure to reduce problematic drinking; the frequency of self-reported heavy/moderate drinking days decreased and days of no to low drinking increased. These effects persisted for three months after intervention. In the current report, we used the transdermal alcohol concentration (TAC) data collected prior to and during the contingency management procedure to provide a detailed characterization of objectively measured alcohol use.

METHODS

Drinkers (n=80) who frequently engaged in risky drinking behaviors were recruited and participated in three study phases: a 4-week Observation phase where participants drank as usual; a 12-week Contingency Management phase where participants received $50 each week when TAC did not exceed 0.03g/dl; and a 3-month Follow-up phase where self-reported alcohol consumption was monitored. Transdermal monitors were worn during the first two phases, where each week they recived $105 for visiting the clinic and wearing the monitor. Outcomes focused on using TAC data to objectively characterize drinking and were used to classify drinking levels as either no, low, moderate, or heavy drinking as a function of weeks and day of week.

RESULTS

Compared to the Observation phase, TAC data indicated that episodes of heavy drinking days during the Contingency Management phase were reduced and episodes of no drinking and low to moderate drinking increased.

CONCLUSIONS

These results lend further support for linking transdermal alcohol monitoring with contingency management interventions. Collectively, studies to date indicate that interventions like these may be useful for both abstinence and moderation-based programs.

Childhood stress exposure among preadolescents with and without family histories of substance use disorders

Having a family history of substance use disorders (FH+) increases risk for developing a substance use disorder. This risk may be at least partially mediated by increased exposure to childhood stressors among FH+ individuals. However, measures typically used to assess exposure to stressors are narrow in scope and vary across studies. The nature of stressors that disproportionately affect FH+ children and how these stressors relate to later substance use in this population are not well understood. The purpose of this study was to assess exposure to a broad range of stressors among FH+ and FH- children to better characterize how exposure to childhood stressors relates to increased risk for substance misuse among FH+ individuals. A total of 386 children (305 FH+, 81 FH-; ages 10-12) were assessed using the Stressful Life Events Schedule before the onset of regular substance use. Both the number and severity of stressors were compared. Preliminary follow-up analyses were done for 53 adolescents who subsequently reported initiation of substance use. FH+ children reported more frequent and severe stressors than did FH- children, specifically in the areas of housing, family, school, crime, peers, and finances. Additionally, risk for substance use initiation during early adolescence was influenced directly by having a family history of substance use disorders and also indirectly through increased exposure to stressors among FH+ individuals. In conclusion, FH+ children experience greater stress across multiple domains, which contributes to their risk for substance misuse and related problems during adolescence and young adulthood. (PsycINFO Database Record

Treatment Needs of Driving While Intoxicated Offenders: The Need for a Multimodal Approach to Treatment

OBJECTIVE

This study aimed to characterize and compare the treatment needs of adults with driving while intoxicated (DWI) offenders recruited from a correctional residential treatment facility and the community to provide recommendations for treatment development.

METHOD

A total of 119 adults (59 residential, 60 community) with at least one DWI offense were administered clinical diagnostic interviews to assess substance use disorders and completed a battery of questionnaires assessing demographic characteristics, legal history, psychiatric diagnoses, medical diagnoses, and health care utilization.

RESULTS

Almost all (96.6%) DWI offenders met clinical diagnostic criteria for an alcohol use disorder, approximately half of the sample also met diagnostic criteria for comorbid substance use disorders, and a substantial proportion also reported psychiatric and medical comorbidities. However, a high percentage were not receiving treatment for these issues, most likely as a result of having limited access to care, because the majority of participants had no current health insurance (64.45%) or primary care physician (74.0%). The residential sample had more extensive criminal histories compared to the community sample but was generally representative of the community in terms of their clinical characteristics. For instance, the groups did not differ in rates of substance use, psychiatric and medical health diagnoses, or the treatment of such issues, with the exception of alcohol abuse treatment.

CONCLUSIONS

DWI offenders represent a clinical population with high levels of complex and competing treatment needs that are not currently being met. Our findings demonstrate the need for standardized screening of DWI offenders and call for the development of a multimodal treatment approach in efforts to reduce recidivism.

Accounting for sex-related differences in the estimation of breath alcohol concentrations using transdermal alcohol monitoring

RATIONALE

Previously, we reported methods to estimate peak breath alcohol concentrations (BrAC) from transdermal alcohol concentrations (TAC) under conditions where alcohol consumption was controlled to produce similar BrAC levels in both sexes.

OBJECTIVE

This study characterized differences in the relationship between BrAC and TAC as a function of sex and developed a model to predict peak BrAC that accounts for known sex differences in peak BrAC.

METHODS

TAC and BrAC were monitored during the consumption of a varying number of beers on different days. Both men (n=11) and women (n=10) consumed one, two, three, four, and five beers at the same rate in a 2-h period. Sex and sex-related variables were considered for inclusion in a multilevel model to develop an equation to estimate peak BrAC levels from TAC.

RESULTS

While peak BrAC levels were significantly higher in women than men, sex differences were not significant in observed TAC levels. This lack of correspondence was evidenced by significant sex differences in the relationship between peak TAC and peak BrAC. The best model to estimate peak BrAC accounted for sex-related differences by including peak TAC, time-to-peak TAC, and sex. This model was further validated using previously collected data.

CONCLUSIONS

The relationship between peak TAC and actual peak BrAC differs between men and women, and these differences can be accounted for in a statistical model to better estimate peak BrAC. Further studies are required to extend these estimates of peak BrAC to the outpatient environment where naturalistic drinking occurs.

Mechanisms of the pellagragenic effect of leucine: stimulation of hepatic tryptophan oxidation by administration of branched-chain amino acids to healthy human volunteers and the role of plasma free tryptophan and total kynurenines

The pellagragenic effect of leucine (Leu) has been proposed to involve modulation of L-tryptophan (Trp) metabolism along the hepatic kynurenine pathway. Here, we discuss some of the mechanisms suggested and report the effects in healthy volunteers of single doses of Leu (4.05-6.75 g) administered in a 16-amino acid mixture on concentrations of plasma Trp and its kynurenine metabolites. Flux of Trp through Trp 2,3-dioxygenase (TDO) is dose-dependently enhanced most probably by Leu and can be attributed to TDO activation. Trp oxidation is better expressed using plasma total kynure-nines, rather than kynurenine, and free, rather than total, Trp. Increased hepatic Trp oxidation may be an additional mechanism of action of branched-chain amino acids in the acute Trp depletion test. Inhibition of intestinal absorption or hepatic uptake of Trp by Leu can be excluded. Potential mechanisms of the aggravation of pellagra symptoms by Leu are discussed.

Increased forebrain activations in youths with family histories of alcohol and other substance use disorders performing a Go/NoGo task

BACKGROUND

Youths with a family history of alcohol and other drug use disorders (FH+) are at a greater risk of developing substance use disorders than their peers with no such family histories (FH-), and this increased risk may be related to impaired maturation of forebrain circuitry. FH+ individuals have shown altered forebrain activity at rest and while performing cognitive tasks. However, it is not fully understood how forebrain activity is altered in FH+ individuals, and ultimately how these alterations may contribute to substance use disorder risk.

METHODS

In this study, we tested 72 FH+ and 32 FH- youths performing a go/no-go task and examined activations in blocks with only go trials (Go Only), blocks with 50% go and 50% no-go trials (Go/NoGo), and a contrast of those 2 blocks.

RESULTS

FH+ youths had significantly greater cerebral activations in both the Go and Go/NoGo blocks than FH- youths in regions including the posterior cingulate/precuneus, bilateral middle/superior temporal gyrus, and medial superior frontal gyrus with no significant group differences in the subtraction between Go Only and Go/NoGo blocks. Additionally, FH+ youths had moderately slower reaction times on go trials in the Go Only blocks.

CONCLUSIONS

Our findings suggest that global activation increase in FH+ youths are modulated by FH density and are not specific to the inhibitory components of the task. This pattern of increased activations in FH+ youths may be at least partially due to impaired forebrain white matter development leading to greater activations/less efficient neural communication during task performance.

Assessment of whole brain white matter integrity in youths and young adults with a family history of substance-use disorders

Individuals with a family history of substance use disorders (FH+) are at a greater risk of developing substance use disorders than their peers with no such family histories (FH-) and this vulnerability is proportional to the number of affected relatives (FH density). The risk for developing substance use disorders peaks during adolescence to early adulthood in the general population, and that is thought to be related to delayed maturation of frontocortical and frontostriatal functional circuits. We hypothesized that FH+ youth and young adults have impaired myelination of frontocortical and frontostriatal white matter tracts. We examined fractional anisotropy (FA) data in 80 FH+ and 34 FH- youths (12.9 ± 1.0 years) and in 25 FH+ and 30 FH- young adults (24.3 ± 3.4 years). FH+ youths had lower FA values in both frontocortical and frontostriatal tracts as well as parietocortical tracts including the anterior, superior and posterior corona radiata and the superior frontal-occipital fasciculus. Moreover, FA values in these tracts were negatively correlated with FH density. FH+ adults had lower FA values in two frontocortical tracts: the genu of the corpus callosum and anterior corona radiata and also significant negative correlations between FA and FH density in these same tracts. In both groups, lower FA values corresponded to higher radial diffusivity suggesting reduced axonal myelination. We interpreted our findings as evidence for impaired myelination of frontal white matter that was proportional to FH density. Our data suggest that deficits may partially resolve with age, paralleling an age-related decline in risk for developing substance use disorders.

Do variable rates of alcohol drinking alter the ability to use transdermal alcohol monitors to estimate peak breath alcohol and total number of drinks?

BACKGROUND

Transdermal alcohol monitoring is a noninvasive method that continuously gathers transdermal alcohol concentrations (TAC) in real time; thus, its use is becoming increasingly more common in alcohol research. In previous studies, we developed models that use TAC data to estimate peak breath alcohol concentration (BrAC) and standard units consumed when the rate of consumption was tightly controlled.

METHODS

Twenty-two healthy participants aged 21 to 52 who reported consuming alcohol on 1 to 4 days per week were recruited from the community. The final study sample included 11 men and 8 women. Both TAC and BrAC were monitored while each participant drank 1, 2, 3, 4, and 5 beers in the laboratory on 5 separate days. In contrast to previous studies, a self-paced alcohol administration procedure was used.

RESULTS

While there was considerable variation in the times it took to consume each beer, key TAC parameters were not affected by pace of drinking. TAC data were then used in combination with the previously derived equations and estimated peak BrAC and standard units of alcohol consumed.

CONCLUSIONS

Transdermal alcohol monitoring can be used to reliably estimate peak BrAC and standard number of units consumed regardless of the rate of consumption, further demonstrating its usefulness in clinical research.

Delay discounting differentiates pre-adolescents at high and low risk for substance use disorders based on family history

BACKGROUND

Youth with family histories of substance use disorders (FH+) are at increased risk for developing substance use disorders relative to those without such histories (FH-). FH+ individuals show deficits in impulse control that parallel those in individuals with substance use disorders. Elucidating how specific components of impulse control are affected in FH+ pre-adolescents would advance our understanding of how deficits in impulse control relate to risk of substance use disorders.

METHOD

A total of 386 children (305 FH+, 81 FH-; ages 10-12) with no histories of regular alcohol or other drug use were compared on measures of delay discounting (Kirby), response inhibition (GoStop Impulsivity Paradigm), and response initiation impulsivity (Immediate Memory Task). The independent associations between these three behavioral measures of impulsivity and FH status were analyzed using logistic regression models.

RESULT

FH+ pre-adolescents performed more impulsively on measures of delay discounting and response inhibition impulsivity, but there were no significant group differences on response initiation impulsivity. When the behavioral impulsivity measures were examined simultaneously, delay discounting was most robustly associated with FH status.

CONCLUSIONS

These results identify deficits in impulse control present in FH+ pre-adolescents before the onset of regular substance use, and suggest that increased delay discounting may be an important behavioral phenotype for pre-adolescents at risk for substance use involvement.

Combining diffusion tensor imaging and magnetic resonance spectroscopy to study reduced frontal white matter integrity in youths with family histories of substance use disorders

Individuals with a family history of substance use disorder (FH+) show impaired frontal white matter as indicated by diffusion tensor imaging (DTI). This impairment may be due to impaired or delayed development of myelin in frontal regions, potentially contributing to this population's increased risk for developing substance use disorders. In this study, we examined high angular resolution DTI and proton magnetic resonance spectroscopy data from the anterior corona radiata were collected in 80 FH+ and 34 FH- youths (12.9 ± 1.0 years old). White matter integrity indices included fractional anisotropy (FA), N-acetylaspartate (NAA), and total choline (tCho). Lower FA suggests decreased myelination. Decreased NAA coupled with higher tCho suggests impaired build-up and maintenance of cerebral myelin and consequently greater breakdown of cellular membranes. We found FH+ youths had lower FA (P < 0.0001) and NAA (P = 0.017) and higher tCho (P = 0.04). FH density (number of parents and grandparents with substance use disorders) was negatively correlated with FA (P < 0.0001) and NAA (P = 0.011) and positively correlated with tCho (P = 0.001). FA was independently predicted by both FH density (P = 0.006) and NAA (P = 0.002), and NAA and tCho were both independent predictors of FH density (P < 0.001). Our finding of lower frontal FA in FH+ youths corresponding to lower NAA and increased tCho is consistent with delayed or impaired development of frontal white matter in FH+ youths. Longitudinal studies are needed to determine how these differences relate to substance use outcomes.