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Dive into the research topics where Justin L. Enggasser is active.

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Featured researches published by Justin L. Enggasser.


Neuropsychopharmacology | 2002

Acute administration of d-amphetamine decreases impulsivity in healthy volunteers.

Harriet de Wit; Justin L. Enggasser; Jerry B. Richards

This study investigated the acute behavioral effects of d-amphetamine on several behavioral indices of impulsivity. Impulsivity has been defined, variously, as difficulty in inhibiting inappropriate behaviors, inability to wait, insensitivity to delayed consequences or an alteration in the perception of time; standardized procedures have been developed to measure these behavioral dimensions. However, it is not known how drugs affect these measures, and few studies have examined more than one measure in a single study. In this study, 36 healthy men and women participated in three sessions, in which they received placebo, 10 mg, or 20 mg d-amphetamine in randomized order. On each session they performed the following five tasks: the Stop Task, which measures behavioral inhibition, a delay discounting task, which measures the relative value of immediate vs. delayed rewards, a delay of gratification task, a Go/No-Go task, and a time estimation task. Subjects also completed mood questionnaires. Amphetamine produced its expected subjective, mood-altering effects, including increases in POMS Friendliness and Elation scales, and ARCI Euphoria and Stimulant scales. On the measures of impulsivity, amphetamine decreased impulsive responding on three of the tasks: on the Stop Task it decreased Stop reaction times without affecting Go reaction time, on the Go/No-Go task, it decreased the number of false alarms, and on the delay discounting measure, amphetamine (20 mg) decreased k values indicating less discounting of delayed reward. Other measures of impulsive behavior were unaffected. These results suggest that acute doses of amphetamine decrease several forms of impulsive behavior. These findings extend and confirm previous findings in humans and laboratory animals.


Journal of Consulting and Clinical Psychology | 2013

Web intervention for OEF/OIF veterans with problem drinking and PTSD symptoms: A randomized clinical trial

Deborah J. Brief; Amy Rubin; Terence M. Keane; Justin L. Enggasser; Monica Roy; Eric Helmuth; John A. Hermos; Mark Lachowicz; Denis Rybin; David Rosenbloom

OBJECTIVE Veterans who served in Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) commonly experience alcohol misuse and symptoms of posttraumatic stress disorder (PTSD) following their return from deployment to a war zone. We conducted a randomized clinical trial to evaluate the efficacy of a newly developed, 8-module, self-management web intervention (VetChange) based on motivational and cognitive-behavioral principles to reduce alcohol consumption, alcohol-related problems, and PTSD symptoms in returning combat veterans. METHOD Six hundred participants, recruited through targeted Facebook ads, were randomized to either an Initial Intervention Group (IIG; n = 404) or a Delayed Intervention Group (DIG; n = 196) that waited 8 weeks for access to VetChange. Primary outcome measures were Drinks per Drinking Day, Average Weekly Drinks, Percent Heavy Drinking Days, and PTSD symptoms. Intent-to-treat analyses compared changes in outcome measures over time between IIG and DIG as well as within-group changes. RESULTS IIG participants demonstrated greater reductions in drinking (p < .001 for each measure) and PTSD symptoms (p = .009) between baseline and end-of-intervention than did DIG participants between baseline and the end of the waiting period. DIG participants showed similar improvements to those in IIG following participation in VetChange. Alcohol problems were also reduced within each group between baseline and 3-month follow-up. CONCLUSIONS Results indicate that VetChange is effective in reducing drinking and PTSD symptoms in OIF/OEF veterans. Further studies of VetChange are needed to assess web-based recruitment and retention methods and to determine VetChanges effectiveness in demographic and clinical sub-populations of returning veterans.


Psychological Assessment | 2014

Temporal stability of DSM-5 posttraumatic stress disorder criteria in a problem-drinking sample.

Terence M. Keane; Amy Rubin; Mark Lachowicz; Deborah J. Brief; Justin L. Enggasser; Monica Roy; John A. Hermos; Eric Helmuth; David Rosenbloom

The 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) reformulated posttraumatic stress disorder (PTSD) based partially on research showing there were 4 main factors that underlie the symptoms of the disorder. The primary aim of this study was to examine the temporal stability of the DSM-5 factors as measured by the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5; Weathers et al., 2010). Confirmatory factor analyses were conducted to examine the structure of DSM-5 PTSD, and temporal stability over 3 time points was examined to determine if the measure reflects a consistent construct over time. Our sample was 507 combat-exposed veterans of Iraq and Afghanistan who enrolled in an online intervention for problem drinking and combat-related stress (Brief et al., 2013). We administered the PCL-5 at baseline, 8-week postintervention, and 3-month follow-up assessments. The DSM-5 model provided an adequate fit to the data at baseline. Tests of equality of form and equality of factor loadings demonstrated stability of the factor structure over time, indicating temporal stability. This study confirmed the results of previous research supporting the DSM-5 model of PTSD symptoms (Elhai et al., 2012; Miller et al., 2013). This is the 1st study to demonstrate the temporal stability of the PCL-5, indicating its use in longitudinal studies measures the same construct over time.


International Journal of Methods in Psychiatric Research | 2014

Strategies to address participant misrepresentation for eligibility in Web-based research.

Jessica M. Kramer; Amy Rubin; Wendy J. Coster; Eric Helmuth; John A. Hermos; David Rosenbloom; Rich Moed; Meghan Dooley; Ying-Chia Kao; Kendra Liljenquist; Deborah J. Brief; Justin L. Enggasser; Terence M. Keane; Monica Roy; Mark Lachowicz

Emerging methodological research suggests that the World Wide Web (“Web”) is an appropriate venue for survey data collection, and a promising area for delivering behavioral intervention. However, the use of the Web for research raises concerns regarding sample validity, particularly when the Web is used for recruitment and enrollment. The purpose of this paper is to describe the challenges experienced in two different Web‐based studies in which participant misrepresentation threatened sample validity: a survey study and an online intervention study. The lessons learned from these experiences generated three types of strategies researchers can use to reduce the likelihood of participant misrepresentation for eligibility in Web‐based research. Examples of procedural/design strategies, technical/software strategies and data analytic strategies are provided along with the methodological strengths and limitations of specific strategies. The discussion includes a series of considerations to guide researchers in the selection of strategies that may be most appropriate given the aims, resources and target population of their studies. Copyright


Journal of Contemporary Psychotherapy | 2011

Web-Based Intervention for Returning Veterans with Symptoms of Posttraumatic Stress Disorder and Risky Alcohol Use

Deborah J. Brief; Amy Rubin; Justin L. Enggasser; Monica Roy; Terence M. Keane

A substantial number of military personnel who have served in Iraq (Operation Iraqi Freedom; OIF) and Afghanistan (Operating Enduring Freedom; OEF) develop symptoms of posttraumatic stress disorder (PTSD) in response to their military experiences and many of these same individuals will drink in a risky or problematic manner following deployment. If left untreated, PTSD symptoms and alcohol problems can become chronic and have a significant, negative impact on the lives of veterans, their families and communities. Further, OIF and OEF service members are often reluctant to seek treatment for mental health symptoms or alcohol problems secondary to stigma. In order to reach this population it is essential that new strategies and venues for delivering evidence-based care are explored. Web-based interventions are uniquely suited to this cohort of veterans in that they have the potential to reach a significant number of veterans who commonly use the Web and who might not otherwise receive care. This article will review the prevalence of PTSD and alcohol problems among OIF and OEF veterans, common barriers they experience with accessing care in traditional mental health settings, and what is known about the effectiveness of Web-based approaches for PTSD and alcohol problems. It also describes the components of a new Web-based intervention, developed by the authors, that uses motivational enhancement and cognitive-behavioral strategies to intervene with returning veterans who report PTSD symptoms and problem drinking. Recommendations for future directions in working with returning veterans with PTSD and alcohol problems will be offered.


Cognitive Therapy and Research | 2007

Cognitive Vulnerability to Depression in Seasonal Affective Disorder: Predicting Mood and Cognitive Symptoms in Individuals with Seasonal Vegetative Changes

Justin L. Enggasser; Michael A. Young

Research indicates that seasonal fluctuations in vegetative functions (e.g., sleep, appetite, and energy) occur to varying degrees in the general population and a large fluctuation in vegetative functioning is often considered the core of seasonal affective disorder (SAD). The purpose of the present study was to determine if, among those with seasonal changes in vegetative functioning, a cognitive vulnerability to depression is associated with an increased risk for developing the cognitive and affective symptoms of SAD. Results indicate that participants with more dysfunctional attitudes, a more ruminative response style, and a more internal attributional style for negative events report experiencing more severe mood and cognitive symptoms of depression during the winter, controlling for the severity of vegetative symptoms. This was the case both for retrospective reports of typical symptoms and prospective reports of actual symptoms. These results provide support for Young’s dual vulnerability model, in which cognitive factors interact with environmentally mediated biological factors in the pathogenesis of full-symptom SAD, and suggest that cognitively-oriented interventions may be useful as adjunctive or alternative treatments for SAD.


Clinical Psychology-science and Practice | 2017

Sexual Traumatic Event Exposure, Posttraumatic Stress Symptomatology, and Alcohol Misuse Among Women: A Critical Review of the Empirical Literature

Kirsten J. Langdon; Amy Rubin; Deborah J. Brief; Justin L. Enggasser; Monica Roy; Marika Solhan; Eric Helmuth; David Rosenbloom; Terence M. Keane

The current review summarizes and critically evaluates the existing literature to shed light on two key questions: (a) the impact of trauma exposure on alcohol use (and vice versa; the impact of alcohol use on risk for trauma exposure) in women, and (b) the nature of PTSD–alcohol misuse comorbidity in women. The secondary aim was to explore moderators or mechanisms of action. Findings suggest that sexual trauma may be especially relevant to alcohol misuse in women. Cross-sectional data generally support PTSD–alcohol misuse associations; however, findings from prospective studies are mixed. Significantly less is known about moderators/mediators of these relations, with the majority of work focused on emotional and motivational processes. Limitations, future directions, and clinical implications are discussed.


American Journal on Addictions | 2018

A randomized controlled trial of a gender-focused addiction model versus 12-step facilitation for women veterans: Gender-Focused Model

Lisa M. Najavits; Justin L. Enggasser; Deborah J. Brief; Edward J. Federman

BACKGROUND AND OBJECTIVES Substance use disorder (SUD) has increased among women, including military veterans, yet SUD treatment was historically designed for males. This randomized controlled trial compared 12 individual sessions of a gender-focused SUD recovery model, A Womans Path to Recovery (WPR) to an evidence-based, non-gender-focused SUD model, 12-Step Facilitation (TSF) for 66 women veterans with current severe SUD. METHODS The primary outcome was substance use; secondary outcomes were associated problems (e.g., psychological); coping skills, and 12-step attendance, with assessment at baseline, end-of-treatment, and 3-month followup. RESULTS Substance use decreased over time, with no difference between conditions. Decreases occurred from baseline to end-of-treatment and baseline to followup and, for drug severity, also from end-of-treatment to followup. Effect sizes were large for alcohol and medium otherwise. Secondary outcomes were largely consistent with this pattern of improvement. Urinalysis/breathalyzer supported self-report. Treatment attendance was 62% for WPR and 57% for TSF (not significantly different). Twelve-step group attendance, surprisingly, did not increase in either condition. DISCUSSION AND CONCLUSIONS WPR provides a useful addition to womens SUD treatment options, with outcomes no different than an established evidence-based model, TSF. Both showed positive impact on substance use and related areas. Our lack of differences based on gender-focus may reflect women veterans being acculturated to a male military environment. Limitations include lack of an untreated control, a sample limited to veterans, and use of a large effect size for power assumptions. SCIENTIFIC SIGNIFICANCE This is the first RCT of a gender-focused approach for women veterans with SUD. (Am J Addict 2018;27:210-216).


American Journal on Addictions | 2018

Adherence to extended release naltrexone: Patient and treatment characteristics: Extended Release Naltrexone Treatment Adherence

Grace Chang; Mitchell Crawford; Michelle Pitts; Abigail Z. Schein; Katherine Goodwin; Justin L. Enggasser

BACKGROUND AND OBJECTIVES Despite the promise of extended release naltrexone in the treatment of the opioid and alcohol use disorders, challenges with initiation and subsequent adherence have limited its potential. The purpose of this study is to identify the patient and treatment characteristics associated with adherence to extended release naltrexone. METHODS Retrospective cohort study of 155 veterans who initiated the medication in FY 2014 and FY2015. Medical records were abstracted for patient and treatment data including preferred drug and utilization of substance use treatment in the year before and after medication initiation. RESULTS Sample characteristics include 94% male, 70% domiciled, 60% without current legal problems, 30% employed, and preferred drug being opioids for 55% and alcohol for 45%. The mean of five extended release naltrexone injections did not differ by preferred drug. Treatment variables associated with medication adherence included concurrent substance use residential, individual, group, and psychiatric therapies (all p < .05) with inpatient detoxification admissions halved afterward (p < .0001) . DISCUSSION AND CONCLUSIONS Whereas most studies of extended release naltrexone have focused on patients with either alcohol or opioid use disorders for 6 months, this study allowed for a direct comparison of adherence in both groups over a year. The average treatment persistence in this veteran sample is greater than described in other public sector studies and may illustrate the importance of concurrent psychosocial therapies. SCIENTIFIC SIGNIFICANCE Results extend the findings of other studies and add to an emerging appreciation of the factors associated with treatment retention for extended release naltrexone. (Am J Addict 2018;27:524-530).


Psychological Trauma: Theory, Research, Practice, and Policy | 2017

Web-based alcohol intervention for veterans: PTSD, combat exposure, and alcohol outcomes.

Deborah J. Brief; Marika B. Solhan; Denis Rybin; Justin L. Enggasser; Amy Rubin; Monica Roy; Eric Helmuth; Amy Schreiner; Meagan Heilman; Lisa Vittorio; David Rosenbloom; Terence M. Keane

Objective: The purpose of the current study was to evaluate the relationship between baseline levels of posttraumatic stress disorder (PTSD), combat exposure, and alcohol outcomes in a sample of Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) veterans using a web-based self-management intervention (VetChange) for problem drinking. Method: The current study focuses on 523 veterans who participated in a larger randomized clinical trial. Analyses in the current study include (a) multivariable linear regression models to assess the relationship between PTSD, combat exposure, and alcohol variables at baseline, and (b) general linear models accounting for correlated data within subjects to analyze change over time for alcohol outcomes as a function of baseline PTSD symptoms, combat exposure, and covariates. Results: There was a positive association between PTSD symptom severity and alcohol use and alcohol problem severity at baseline. However, participants with higher baseline PTSD symptoms demonstrated a significantly greater reduction in alcohol use during the intervention and a greater reduction in alcohol problems from baseline to 3-month follow-up. Combat exposure severity was positively associated with alcohol problems at baseline. However, veterans with higher exposure demonstrated a greater reduction in average weekly drinking between end of intervention and follow-up, and otherwise showed changes similar to participants with lower exposure. Conclusions: Higher levels of baseline PTSD symptoms and combat exposure severity did not prevent OEF/OIF veterans from achieving positive alcohol outcomes through participation in a self-management web intervention for problem drinking.

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Monica Roy

VA Boston Healthcare System

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Mark Lachowicz

VA Boston Healthcare System

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