Frontopolar multifocal transcranial direct current stimulation reduces conditioned fear reactivity during extinction training: A pilot randomized controlled trial.

Exposure-based therapies for anxiety and related disorders are believed to depend on fear extinction learning and corresponding changes in extinction circuitry. Frontopolar multifocal transcranial direct current stimulation (tDCS) has been shown to improve therapeutic safety learning during in vivo exposure and may modulate functional connectivity of networks implicated in fear processing and inhibition. A pilot randomized controlled trial was completed to determine the effects of frontopolar tDCS on extinction learning and memory. Community volunteers (n = 35) completed a 3-day fear extinction paradigm with measurement of electrodermal activity. Participants were randomized (single-blind) to 20-min of sham (n = 17, 30 s. ramp in/out) or active (n = 18) frontopolar (anode over Fpz, 10-10 EEG) multifocal tDCS (20-min, 1.5 mA) prior to extinction training. Mixed ANOVAs revealed a significant group*trial effect on skin conductance response (SCR) to the conditioned stimulus (CS + ) during extinction training (p = 0.007, Cohen's d = 0.55). The effects of frontopolar tDCS were greatest during the first two extinction trials, suggesting that tDCS may have promoted fear inhibition prior to safety learning. Return of fear to the CS + during tests were comparable across conditions (ps > 0.50). These findings suggest that frontopolar tDCS may modulate the processing of threat cues and associated circuitry or promote the inhibition of fear. This has clear implications for the treatment of anxiety and related disorders with therapeutic exposure.

Interactive association of posttraumatic stress disorder, apolipoprotein ε4 genotype, and age on cognitive functioning.

BACKGROUND: The ε4 allele of the apolipoprotein (APOE) gene and posttraumatic stress disorder (PTSD) are associated with cognitive deficits. Both associations may vary depending on age. No previous study has examined a possible three-way interaction between APOE ε4, PTSD, and age on cognitive functioning. METHODS: Data were analyzed from 1244 European-American U.S. military veterans who participated in the 2011 National Health and Resilience in Veterans Study (NHRVS). Analyses of covariance were used to examine the main effects and interactions of APOE ε4, PTSD, and age on learning/working memory (LWM) and attention/psychomotor (APM) performance. RESULTS: A significant three-way interaction between APOE ε4, PTSD, and age on the LWM composite (ηp 2  = 0.011) was observed such that the main effect of APOE ε4 on LWM was only significant for older participants with PTSD. A significant two-way interaction between PTSD and age on the APM composite (ηp 2  = 0.011) was observed such that the main effect of PTSD on APM was only significant in older participants. CONCLUSION: Older APOE ε4 carriers with probable PTSD showed poorer LWM performance relative to other groups. Aging-related associations on APM performance were most pronounced in veterans with PTSD. These data are preliminary evidence that identification and treatment of PTSD may be beneficial for individuals at risk for age-related cognitive impairment.

Assessment of Comorbid Obsessive-Compulsive Disorder and Posttraumatic Stress Disorder.

Obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD) are commonly comorbid and share prominent features (e.g., intrusions, safety behaviors, and avoidance). Excellent self-report and clinician-administered assessments exist for OCD and PTSD individually, but few assess both disorders, and even fewer provide instruction on differential diagnosis or detection of comorbid OCD and PTSD. To address this gap in the literature, the current paper aims to (1) highlight diagnostic and functional similarities and differences between OCD and PTSD to inform differential diagnosis, (2) outline assessment recommendations for individuals with suspected comorbid OCD and PTSD, OCD with a significant trauma history or posttraumatic symptoms, or PTSD with significant obsessive-compulsive symptoms, and (3) explore future directions to evaluate and improve methods for assessing co-occurring OCD and PTSD.

Interactive effects of the BDNF Val66Met polymorphism and posttraumatic stress disorder on cognition in U.S. military veterans.

Posttraumatic stress disorder (PTSD) is associated with mild-to-moderate deficits in cognition. The Met allele of the brain-derived neurotrophic factor (BDNF) Val66Met gene may also be associated with deficits in cognition. However, findings are inconsistent and may be sensitive to moderating variables such as psychopathology. While emerging research suggests that PTSD and the Met allele may interact, few studies have replicated this effect or examined the interactive effect of PTSD and the Met allele on subjective cognition. To address this gap, the current study analyzed data from European-American (EA) U.S. military veterans (n = 1244) who participated in the National Health and Resilience in Veterans Study (NHRVS) to examine the main and interactive effects of BDNF Val66Met genotype and probable PTSD on objective and subjective cognition. Results revealed significant (p's < 0.001) interactions between Met allele carrier status and probable PTSD in objective and subjective cognition. Among individuals with probable PTSD (n = 131), the Met allele was associated with poorer objective (p < .001, d = 0.62) and subjective cognition (p = .001, d = 0.53). Among individuals without PTSD (n = 1113), the Met allele was not significantly associated with objective or subjective cognition. These findings suggest that PTSD may moderate the association between Met allele carrier status and cognition. Implications of these results for the mitigation of cognitive dysfunction in older veterans are discussed.