Matthew T. Tull, Ph.D. - US grants

[unreadable] DESCRIPTION (provided by applicant): Substance use disorders (SUDs) are highly comorbid with posttraumatic stress disorder (PTSD; Kessler et al., 1995), and this comorbidity is associated with significant problems, including a greater likelihood of substance use treatment failure (e.g., Ouimette, Brown et al., 1998). Further, research suggests that it is not traumatic exposure per se that puts substance users at greater risk for worse outcomes, but instead the development of PTSD (Chilcoat & Breslau, 1998). Despite evidence that there is something unique to PTSD that negatively affects the course and outcome of substance use treatment, studies have yet to identify the specific mechanisms that may influence the maintenance of substance use among individuals with PTSD. It has been suggested that selective attentional biases may play a central role in the development and maintenance of drug use behavior, as well as relapse to substance use following treatment (Marlatt & Gordon, 1985; Robinson & Berridge, 1993; Tiffany, 1990). This may especially be the case among substance users with PTSD, as research suggests that substance users with PTSD may be more susceptible to become sensitized to drug cues as a result of the negative reinforcement substance use provides in regard to PTSD symptom reduction. That is, consistent with Robinson & Berridge's (1993) incentive-sensitization model, as drugs are increasingly used to self-medicate PTSD symptoms, drug-related stimuli may become more salient and "attention-grabbing" due to their ability to predict reward (i.e., symptom reduction). This is especially likely when PTSD symptoms are being experienced, given the potential for substances to provide immediate relief from certain PTSD symptoms, such as hyperarousal or re-experiencing. Nevertheless, this has not been tested directly. To address this gap in the literature, we will examine if crack/cocaine users with PTSD in an inner-city residential treatment center exhibit a greater attentional bias for drug-related cues, compared to their counterparts with a history of trauma but no current or lifetime history of PTSD, following exposure to a trauma cue. Evidence for greater selective attention for crack/cocaine imagery in the presence of trauma-related cues among PTSD- SUD participants would suggest a possible pathway through which PTSD is associated with greater relapse rates, and has the potential to aid in the eventual development of effective interventions that could be integrated into standard treatments utilized in residential treatment centers. Further, by utilizing an inner-city minority population, this study has the potential to reduce disparity associated with research in and the treatment of PTSD and SUDs among inner-city substance users. This study has specific relevance for underserved and understudied populations. The identification of heightened drug-related attentional biases following exposure to a trauma cue among crack/cocaine users with PTSD has the potential to aid in the development of effective interventions that could be integrated into standard treatments utilized in inner-city residential treatments settings, thus reducing vulnerabililty for treatment failure within this population. Consequently, this study will have tremendous public health benefits. [unreadable] [unreadable] [unreadable]

[unreadable] DESCRIPTION (provided by applicant): Substance use disorders (SUDs) are highly comorbid with posttraumatic stress disorder (PTSD; Kessler et al., 1995), and this particular comorbidity is associated with a greater likelihood of substance use treatment failure (e.g., Ouimette et al., 1998). Further, research suggests that it is not traumatic exposure per se that puts substance users at greater risk for treatment failure, but whether or not PTSD is present (Chilcoat & Breslau, 1998). Despite some evidence that there is something unique to the presence of PTSD that negatively affects the course and outcome of substance use treatment, studies have not yet comprehensively examined whether this heightened risk is due to current PTSD, past PTSD, or simply a consequence of severe past traumatic exposure. Further, studies have yet to explore the specific mechanisms underlying this increased risk. Mechanisms may be identified from the self-medication model of substance use (Brady et al., 2004). Building from this model, SUD patients with current PTSD may be at risk for treatment drop-out to the extent to which they exhibit emotional vulnerabilities in the form of (a) emotion deregulation; (b) anxiety sensitivity; (c) distress intolerance; (d) emotional avoidance; and/or e) HPA axis dysfunction. To test the mediational role of these variables in treatment drop-out, we will examine four groups (n = 50/group) of inner-city drug users in a residential treatment center: (1) SUD patients with no history of DSM-IV PTSD criterion A traumatic exposure; (2) SUD patients with a history of DSM-IV PTSD criterion A traumatic exposure but not meeting criteria for current or past PTSD; (3) SUD patients with a history of DSM-IV PTSD criterion A traumatic exposure not meeting criteria for current PTSD (past month), but meeting criteria for past PTSD (criteria met for a PTSD diagnosis before one month ago); and (4) SUD patients meeting criteria for current PTSD (which includes the presence of criterion A traumatic exposure). We expect that SUD patients with current PTSD, as compared to all other groups, will exhibit the highest rates of treatment drop-out. Further, emotion dysregulation, anxiety sensitivity, emotional avoidance, low distress tolerance, and HPA axis dysfunction will mediate this relationship, even when controlling for variables often associated with treatment failure (e.g., demographics, negative affect, treatment readiness, severity of past traumatic exposure, level of drug dependence, psychiatric comorbidity). [unreadable] [unreadable] [unreadable]

DESCRIPTION (provided by applicant): Posttraumatic stress disorder (PTSD) and substance use disorders (SUDs) co-occur with high frequency (Brady et al., 2004;Cottler et al., 1992;Jacobson et al., 2001), and this diagnostic co-occurrence has great clinical and public health significance. In particular, research indicates that the presence of co-occurring PTSD among individuals with a SUD is associated with heightened risk for a variety of risky and impulsive behaviors and associated negative clinical outcomes, including more severe substance use patterns (Back et al., 2000;Cottler et al., 1992;Najavits et al., 2007;Salgado et al., 2007), greater legal problems (Najavits et al., 1999, 2007;Ouimette et al., 1999), greater risky sexual and drug use behavior (Plotzker et al., 2007), greater risk for HIV infection (Hoff et al., 1997), and quicker relapse to substance use following discharge from SUD treatment (Hien et al., 2000;Ouimette et al., 1999, 2007). Further, findings that the worse treatment outcomes observed among SUD patients with (vs. without) PTSD are not the result of simply greater comorbidity in general (Ouimette et al., 1999) or a history of traumatic exposure (Hien et al., 2000) suggest that there is something unique to the presence of PTSD among substance users that places them at greater risk for negative clinical outcomes. Despite these findings, as well as preliminary findings of higher levels of risk-taking (as assessed through a laboratory-based task) in general among cocaine dependent inpatients with PTSD (vs. those without PTSD;Tull, Trotman, et al., 2009), no studies have examined the factors or contexts that precipitate risky behavior within a PTSD-SUD population, or the extent to which substance of choice influences risky behavior among PTSD-SUD patients. Thus, the proposed experimental study seeks to extend extant research in this area by examining the effect of imaginal trauma cue exposure on risk-taking among 210 trauma-exposed SUD patients (dependent on cocaine only, alcohol only, or cocaine and alcohol) with or without PTSD. On separate days, SUD patients with a history of Criterion A traumatic exposure will be exposed to a neutral cue or a personalized imaginal trauma cue. Following cue exposure, participants will complete two established behavioral measures of risk-taking, the Balloon Analogue Risk Task (Lejuez et al., 2002) and the Iowa Gambling Task (Bechara et al., 1994). We will examine the effect of trauma cue exposure (vs. neutral cue exposure), substance of choice (cocaine vs. alcohol vs. cocaine-alcohol dependence), and PTSD status (current PTSD vs. no history of PTSD) on risk-taking. We expect to find main effects of cocaine dependence and PTSD on risk-taking, as well as a three-way interaction between cue exposure, substance of choice, and PTSD status. Specifically, we expect that cocaine dependent patients with PTSD will exhibit the highest levels of risk-taking following trauma cue exposure than all other groups. Biological (salivary cortisol), physiological (heart rate, electrodermal response), and self-reported reactivity to cues will also be examined to better understand the factors that may lead to risk-taking among PTSD-SUD patients, thus speaking to its function. PUBLIC HEALTH RELEVANCE: By examining the effects of trauma cue exposure, substance of choice, and PTSD status on risk-taking among low SES minority substance users in rural Mississippi, the proposed study will play an important role in reducing disparities in research on the effects of PTSD among SUD patients. In addition, by improving our understanding of the pathways through which PTSD and SUDs may contribute to risky behavior in this population, results from this study will facilitate the development of targeted prevention and intervention programs - a particularly relevant consideration for treatment centers in areas with limited mental health resources.