Browsing by Author "Amstadter, Ananda"

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    Impulsivity and Comorbid PTSD-Binge Drinking
    (Taylor & Francis, 2018) Walker, Jesse; Bountress, Kaitlin E.; Calhoun, Casey D.; Metzger, Isha W.; Adams, Zachary; Amstadter, Ananda; Thomas, Suzanne; Danielson, Carla Kmett; Psychiatry, School of Medicine
    Objective: Trauma exposure is common, with estimates of 28% to 90% of adults reporting at least one traumatic event over their lifetime. Those exposed to traumatic events are at risk for alcohol misuse (i.e., binge drinking), posttraumatic stress disorder (PTSD), or both. A potential underlying mechanism for this comorbidity is increased impulsivity-the tendency to act rashly. Little work to date has examined the impact of different impulsogenic traits on this comorbidity. Methods: This study (n = 162) investigated trauma-exposed young adults (aged 21-30) who had endorsed a lifetime interpersonal trauma. In addition, three impulsogenic traits (motor, nonplanning, and attentional) were measured. Results: Over and above the covariates for age, gender, race, and traumatic events, greater attentional impulsivity was associated with greater likelihood of meeting criteria for PTSD and binge drinking, compared to meeting criteria for PTSD, binge drinking, or neither. Neither nonplanning impulsivity nor motor impulsivity exerted unique effects. Conclusions: Young adults who report difficulty attending to immediate stimuli within their environment may be unable to think about and/or process the traumatic event, potentially increasing risk for PTSD and maladaptive coping skills to manage this distress (e.g., alcohol misuse, binge drinking).
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    Potential causal effect of posttraumatic stress disorder (PTSD) on alcohol use disorder and alcohol consumption in individuals of European descent: A Mendelian Randomization Study
    (Wiley, 2021) Bountress, Kaitlin E.; Wendt, Frank; Bustamante, Daniel; Agrawal, Arpana; Webb, Bradley; Gillespie, Nathan; Edenberg, Howard; Sheerin, Christina; Johnson, Emma; The Psychiatric Genomics Consortium Posttraumatic Stress Disorder Working Group; Polimanti, Renato; Amstadter, Ananda; Biochemistry and Molecular Biology, School of Medicine
    Background: Posttraumatic stress disorder (PTSD) often co-occurs with alcohol consumption (AC) and alcohol use disorder (AUD). However, it is unknown whether the same etiologic influences that underlie PTSD co-occurring with AUD are those that underlie PTSD and AC individually. Methods: This study used large-scale genome-wide association study (GWAS) data to test whether PTSD and drinks per week [DPW]/AUD are causally related to one another, and, if so, whether PTSD precedes DPW/AUD and/or vice versa. We used Mendelian Randomization methods to analyze European ancestry GWAS summary statistics from the Psychiatric Genomics Consortium (PGC; PTSD), GWAS & Sequencing Consortium of Alcohol and Nicotine Use (GSCAN; DPW), and the Million Veteran Program (MVP; AUD). Results: PTSD exerted a potentially causal effect on AUD (β = 0.039, SE = 0.014, p = 0.005), but not on DPW (β = 0.002, SE = 0.003, p = 0.414). Additionally, neither DPW (β = 0.019, SE = 0.041, p = 0.637) nor AUD (β = 8.87 × 10-4 , SE = 0.001, p = 0.441) exerted a causal effect on PTSD. Conclusions: These findings are consistent with the self-medication model, in which individuals misuse alcohol to cope with aversive trauma-related symptoms. These findings extend latent analysis and molecular findings of shared and correlated risk between PTSD and alcohol phenotypes. Given the health behaviors associated with these phenotypes, these findings are important in that they suggest groups to prioritize for prevention efforts. Further, they provide a rationale for future preclinical and clinical studies examining the biological mechanisms by which PTSD may impact AUD.