Intermittent theta burst stimulation and functional connectivity in people living with HIV/AIDS who smoke tobacco cigarettes: a preliminary pilot study

Background

People living with HIV (PLWHA) smoke at three times the rate of the general population and respond poorly to cessation strategies. Previous studies examined repetitive transcranial magnetic stimulation (rTMS) over left dorsolateral prefrontal cortex (L. dlPFC) to reduce craving, but no studies have explored rTMS among PLWHA who smoke. The current pilot study compared the effects of active and sham intermittent theta-burst stimulation (iTBS) on resting state functional connectivity (rsFC), cigarette cue attentional bias, and cigarette craving in PLWHA who smoke.

Methods

Eight PLWHA were recruited (single-blind, within-subject design) to receive one session of iTBS (n=8) over the L. dlPFC using neuronavigation and, four weeks later, sham iTBS (n=5). Cigarette craving and attentional bias assessments were completed before and after both iTBS and sham iTBS. rsFC was assessed before iTBS (baseline) and after iTBS and sham iTBS.

Results

Compared to sham iTBS, iTBS enhanced rsFC between the L. dlPFC and bilateral medial prefrontal cortex and pons. iTBS also enhanced rsFC between the right insula and right occipital cortex compared to sham iTBS. iTBS also decreased cigarette craving and cigarette cue attentional bias.

Conclusion

iTBS could potentially offer a therapeutic option for smoking cessation in PLWHA.

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.

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.

Fear of sin and fear of God: Scrupulosity predicts women's daily experiences of mental contamination following sexual trauma

Mental contamination refers to feelings of dirtiness in response to thoughts, images, or memories. Mental contamination is frequently reported after sexual trauma and is associated with symptoms of posttraumatic stress disorder (PTSD). Differences in individuals' views about morality and purity may influence the severity of mental contamination, though this has been studied primarily outside of samples assessed for trauma and/or PTSD. The present study addressed this gap by investigating scrupulosity as a prospective predictor of daily sexual trauma-related mental contamination and PTSD symptoms. Participants included 40 adult women with a history of sexual trauma and current sexual trauma-related mental contamination who completed baseline diagnostic interviews and questionnaires followed by two assessments every day for 2 weeks. The results indicate that scrupulosity was positively correlated with PTSD symptom severity and sexual trauma-related mental contamination at baseline. Scrupulosity was also a prospective predictor of increased daily sexual trauma-related mental contamination, B = 0.19, SE = 0.07, p = .010, but not daily PTSD symptoms, B = -0.10, SE = .08, p = .198. The findings indicate that scrupulosity may be an important factor in understanding recovery from sexual assault.

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.

Obsessive-Compulsive Symptoms and Daily Experiences of Posttraumatic Stress and Mental Contamination Following Sexual Trauma

Although cross-sectional research highlights similarities between symptoms of obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD) among individuals exposed to sexual trauma, little is known about how these disorders relate over time. The goal of the present study was to examine whether 1) OCD symptoms prospectively predicted daily symptoms of PTSD, and 2) OCD and PTSD symptoms prospectively predicted daily experiences of sexual trauma-related mental contamination (i.e., dirtiness in the absence of a physical pollutant). Forty-one women with a sexual trauma history completed baseline measures of OCD and PTSD, as well as twice-daily assessments of PTSD symptoms and mental contamination over a two-week period. Total OCD symptoms and the unacceptable thoughts dimension significantly predicted daily PTSD symptoms after accounting for other OCD dimensions. Only total OCD symptoms significantly predicted daily mental contamination when examined together with total PTSD symptoms. No individual PTSD or OCD clusters/dimensions significantly predicted daily mental contamination when examined simultaneously. Findings from this study highlight the nuanced associations among OCD symptoms, PTSD symptoms, and experiences of mental contamination. Future research is needed to further understand the development of PTSD, OCD, and mental contamination over time to inform targets for intervention.

Transcranial direct current stimulation targeting the medial prefrontal cortex modulates functional connectivity and enhances safety learning in obsessive-compulsive disorder: Results from two pilot studies

BACKGROUND

Exposed-based psychotherapy is a mainstay of treatment for obsessive-compulsive disorder (OCD) and anxious psychopathology. The medial prefrontal cortex (mPFC) and the default mode network (DMN), which is anchored by the mPFC, promote safety learning. Neuromodulation targeting the mPFC might augment therapeutic safety learning and enhance response to exposure-based therapies.

METHODS

To characterize the effects of mPFC neuromodulation on functional connectivity, 17 community volunteers completed resting-state functional magnetic resonance imaging scans before and after 20 min of frontopolar anodal multifocal transcranial direct current stimulation (tDCS). To examine the effects of tDCS on therapeutic safety learning, 24 patients with OCD completed a pilot randomized clinical trial; they were randomly assigned (double-blind, 50:50) to receive active or sham frontopolar tDCS before completing an in vivo exposure and response prevention (ERP) challenge. Changes in subjective emotional distress during the ERP challenge were used to index therapeutic safety learning.

RESULTS

In community volunteers, frontal pole functional connectivity with the middle and superior frontal gyri increased, while connectivity with the anterior insula and basal ganglia decreased (ps < .001, corrected) after tDCS; functional connectivity between DMN and salience network also decreased after tDCS (ps < .001, corrected). OCD patients who received active tDCS exhibited more rapid therapeutic safety learning (ps < .05) during the ERP challenge than patients who received sham tDCS.

CONCLUSIONS

Frontopolar tDCS may modulate mPFC and DMN functional connectivity and can accelerate therapeutic safety learning. Though limited by small samples, these findings motivate further exploration of the effects of frontopolar tDCS on neural and behavioral targets associated with exposure-based psychotherapies.

Evaluating the mediating effects of perceived vulnerability to disease in the relation between disgust and contamination-based OCD

Contamination-based obsessive-compulsive disorder (OCD) is thought to develop and be maintained by excessive propensity to experience disgust, particularly in response to perceived contaminants, and dysfunctional threat appraisals pertaining to illness. The present studies attempted to integrate these lines of research by testing the degree to which contamination-based OCD is associated with individual differences in disgust propensity and sensitivity, affective distress in response to perceived contaminants, and perceived threat of illness. In Study 1, a convenience sample of 185 adults completed self-report scales assessing obsessive-compulsive symptoms, disgust propensity and sensitivity, germ aversion, and perceived infectability. Multivariate regression showed that disgust propensity and germ aversion were the only significant predictors of contamination-based obsessions and compulsions. Exploratory analyses suggested that there was a significant indirect effect of disgust propensity on contamination-based obsessions and compulsions via germ aversion. Findings from Study 1 were replicated using a sample of twenty-six obsessive-compulsive participants. Despite the substantially smaller sample, the proportion of the total effects attributable to the mediating effect of germ aversion was comparable, consistent with a significant partial mediation in both samples. These results together suggest that contamination-based OCD symptoms are likely maintained and motivated by basic affective processes.

Self-reported exercise frequency and PTSD: results from the National Health and Resilience in Veterans Study

OBJECTIVE

Physical exercise may serve as a protective factor for posttraumatic stress disorder (PTSD), but little is known about whether physical exercise is associated with PTSD in population-based samples of military veterans.

METHODS

We analyzed cross-sectional data on the relation between self-reported physical exercise frequency and the prevalence of probable PTSD in a nationally representative sample of 2832 U.S. military veterans who participated in the National Health and Resilience in Veterans Study.

RESULTS

A "U-shaped" association best explained the relation between self-reported exercise frequency and the prevalence of probable PTSD. Compared to veterans without probable PTSD, those with probable PTSD were nearly twice as likely to report no weekly exercise (52.3% vs. 29.3%) or daily (7 days/week) exercise (15.2% vs. 8.5%) and were nearly half as likely to report exercising a median of 3.5 days/week (32.6% vs. 62.1%). No exercise was associated with greater severity of emotional numbing and lower severity of anxious arousal symptoms, while daily exercise was associated with greater severity of re-experiencing symptoms.

CONCLUSIONS

Results of this study suggest a "U-shaped" association between self-reported exercise frequency and the prevalence of probable PTSD among U.S. veterans. Veterans with probable PTSD were more likely than those without probable PTSD to report not exercising at all or exercising every day and were less likely to report exercising 1-6 days per week. Clinical implications of these findings are discussed.

The effects of depression on the treatment of OCD in a residential sample

Studies investigating the impact of depressive symptoms on obsessive-compulsive disorder (OCD) treatment have yielded mixed findings. The purpose of the study is to extend previous research, which primarily used outpatient samples, to determine whether depression affects OCD treatment outcome among patients receiving intensive residential treatment. OCD patients receiving residential treatment based primarily on exposure and response prevention (ERP) provided data regarding symptoms of depression and OCD at admission and discharge. Patients reported large and significant reductions in OCD symptoms over the course of treatment. Change in OCD symptoms was not significantly affected by depressive symptoms, including patients with severe depressive symptoms. Change in depressive symptoms over the course of treatment was, however, robustly related to change in OCD symptoms, especially among patients who began treatment with severe symptoms of depression. These findings suggest that cognitive-behavior therapy delivered in a residential treatment setting drastically reduces OCD symptoms regardless of depressive symptoms.

The Effect of Trait and State Disgust on Fear of God and Sin

There is a growing literature suggesting disgust plays a major role in religiosity. However, the relationships between specific domains of disgust sensitivity and general religious fundamentalism or religious scrupulosity remains unknown and a lack of experimental data prevents the drawing of causal inferences about the potential effects of disgust on religiosity. Two studies are reported that examined the relationship between specific types of disgust sensitivity (i.e., pathogen, sexual, and moral disgust) and specific religious beliefs (i.e., fear of sin and fear of God). In the first study it was found that sexual disgust and pathogen disgust were significantly correlated with fear of sin and fear of God, respectively. In the second study the experimental induction of disgust led to greater fear of sin but not to the fear of God. These findings suggest that pathogen and sexual disgust sensitivities may serve as effective mechanisms for inflated scrupulosity. Taken together the outcomes from both studies converge on a greater understanding of the ‘Human Behavioral Immune System’ model that can account for social behavior with the evolution of adaptive benefit and perhaps more importantly highlights the possible drivers of specific religious behavior.

Posttraumatic Mental Contamination and the Interpersonal Psychological Theory of Suicide: Effects via DSM-5 PTSD Symptom Clusters

Research has yet to establish a relationship between posttraumatic mental contamination and suicide risk, despite theoretical overlap. The present study examined relationships between posttraumatic mental contamination and suicide risk via posttraumatic stress symptom clusters and appraisals of perceived burdensomeness and thwarted belongingness. Trauma-exposed participants (N=183) completed measures of posttraumatic mental contamination, posttraumatic stress symptoms, thwarted belongingness, perceived burdensomeness, and suicide risk. Findings revealed significant indirect effects of posttraumatic mental contamination on suicide risk via all posttraumatic stress symptom clusters. Significant serial indirect effects of posttraumatic mental contamination on suicide risk were observed via posttraumatic avoidance and arousal/reactivity and, subsequently, via thwarted belongingness and perceived burdensomeness. Serial models via posttraumatic re-experiencing and negative cognitions/mood symptoms were nonsignificant. Results suggest that posttraumatic mental contamination may increase suicide risk via posttraumatic stress symptom severity, and maladaptive interpersonal appraisals may explain these links through distinct symptom pathways. Implications for posttraumatic suicide risk are discussed.

Disgust sensitivity mediates the effects of race on contamination aversion

African Americans report greater contamination aversion than European Americans. Few studies have attempted to identify potential causes for this elevated contamination aversion, though existing research and theory suggests this may be partly due to concomitant heightened disgust sensitivity. The present study examined the relations between race, disgust sensitivity, and contamination aversion among African and European Americans. A convenience sample of fourhundred and twenty-nine participants completed the Disgust Scale - Revised (DS-R) and the Padua Inventory - Revised (PI-R). African Americans endorsed greater disgust sensitivity (DS-R total) - particularly on the core and contamination subscales of the DS-R - and scored higher on the contamination subscale of the PI-R (but not on other subscales) than European Americans. Mediational analyses revealed a significant total effect of race on contamination aversion and a significant indirect effect of race on contamination aversion through disgust sensitivity; the direct effect of race on contamination aversion remained significant even after controlling for race. These findings suggest that elevated contamination aversions among African Americans may be partly due to elevated disgust sensitivity. If confirmed with larger and clinical samples, and more robust experimental methods, this relationship may prove to have implications for the treatment of contamination-based obsessive-compulsive disorder (OCD) among African Americans.

Developing image sets for inducing obsessive-compulsive checking symptoms

Visual stimuli are often used for obsessive-compulsive (OC) symptom provocation in research studies. We tested the induction of anxiety and OC checking symptoms across different types of checking provocation stimuli in three populations: individuals with obsessive compulsive disorder (OCD), individuals with checking symptoms but without a diagnosis of OCD, and control individuals with neither checking symptoms nor a clinical diagnosis. One set of provocative images depicted objects that are commonly associated with checking anxiety. Another set ('enhanced provocative images') depicted similar objects but also included contextual cues suggesting a specific harmful scenario that could occur. As expected, the enhanced provocative images were more effective at inducing anxiety and OC symptoms than the standard provocative images. Future studies requiring checking symptom provocation should therefore consider incorporating similarly suggestive images. Individuals with clinical OCD reported the greatest provocation in response to these images, followed by those with nonclinical checking, followed by control individuals. Thus, these stimuli are able to provoke OC checking symptoms and anxiety differentially across groups, with the intensity of provocation reflecting diagnostic status. All groups demonstrated a similar qualitative pattern of provocation across images. Finally, in all groups, reported anxiety closely tracked intrusive thoughts and checking urges.

The role of stress in the pathogenesis and maintenance of obsessive-compulsive disorder

Individuals with obsessive-compulsive disorder often identify psychosocial stress as a factor that exacerbates their symptoms, and many trace the onset of symptoms to a stressful period of life or a discrete traumatic incident. However, the pathophysiological relationship between stress and obsessive-compulsive disorder remains poorly characterized: it is unclear whether trauma or stress is an independent cause of obsessive-compulsive disorder symptoms, a triggering factor that interacts with a preexisting diathesis, or simply a nonspecific factor that can exacerbate obsessive-compulsive disorder along with other aspects of psychiatric symptomatology. Nonetheless, preclinical research has demonstrated that stress has conspicuous effects on corticostriatal and limbic circuitry. Specifically, stress can lead to neuronal atrophy in frontal cortices (particularly the medial prefrontal cortex), the dorsomedial striatum (caudate), and the hippocampus. Stress can also result in neuronal hypertrophy in the dorsolateral striatum (putamen) and amygdala. These neurobiological effects mirror reported neural abnormalities in obsessive-compulsive disorder and may contribute to an imbalance between goal-directed and habitual behavior, an imbalance that is implicated in the pathogenesis and expression of obsessive-compulsive disorder symptomatology. The modulation of corticostriatal and limbic circuits by stress and the resultant imbalance between habit and goal-directed learning and behavior offers a framework for investigating how stress may exacerbate or trigger obsessive-compulsive disorder symptomatology.

Posttraumatic Stress Disorder: an integrated overview and neurobiological rationale for pharmacology

Thirty years of research on the biology of posttraumatic stress disorder now provides a foundation for hypotheses related to the mechanisms underlying the pharmacotherapy of this disorder. Only two medications, sertraline and paroxetine, are approved by the U.S. Food and Drug Administration for the treatment of PTSD. While these medications are somewhat effective, other treatment mechanisms must be explored to address the unmet need for effective treatment. This article provides a concise summary of advances in our understanding of the neurobiology of PTSD that suggest novel approaches to pharmacotherapy.

Spatial Scaling of the Profile of Selective Attention in the Visual Field

Neural mechanisms of selective attention must be capable of adapting to variation in the absolute size of an attended stimulus in the ever-changing visual environment. To date, little is known regarding how attentional selection interacts with fluctuations in the spatial expanse of an attended object. Here, we use event-related potentials (ERPs) to investigate the scaling of attentional enhancement and suppression across the visual field. We measured ERPs while participants performed a task at fixation that varied in its attentional demands (attentional load) and visual angle (1.0° or 2.5°). Observers were presented with a stream of task-relevant stimuli while foveal, parafoveal, and peripheral visual locations were probed by irrelevant distractor stimuli. We found two important effects in the N1 component of visual ERPs. First, N1 modulations to task-relevant stimuli indexed attentional selection of stimuli during the load task and further correlated with task performance. Second, with increased task size, attentional modulation of the N1 to distractor stimuli showed a differential pattern that was consistent with a scaling of attentional selection. Together, these results demonstrate that the size of an attended stimulus scales the profile of attentional selection across the visual field and provides insights into the attentional mechanisms associated with such spatial scaling.

KETAMINE'S MECHANISM OF ACTION: A PATH TO RAPID-ACTING ANTIDEPRESSANTS

Major depressive disorder (MDD) is a common and debilitating psychiatric disorder. Traditional antidepressants are of limited efficacy and take weeks to months to yield full therapeutic effects. Thus, there is a clear need for effective rapid-acting antidepressant medications. The N-methyl-d-aspartate receptor (NMDA-R) antagonist, ketamine, has received a great deal of attention over the last 20 years due to the discovery that a single subanesthetic dose leads to a rapid antidepressant effect in individuals with treatment-resistant depression. Animal and human research suggest that ketamine's antidepressant effects are mediated by a glutamate surge that leads to a cascade of events that result in synaptogenesis and reversal of the negative effects of chronic stress and depression, particularly within the prefrontal cortex (PFC). Preclinical and clinical data have provided compelling insights into the mechanisms underlying the rapid-acting antidepressant effects of ketamine. This review discusses stress-related neurobiology of depression and the safety, tolerability, and efficacy of ketamine for MDD, along with a review of ketamine's mechanism of action and prospective predictors of treatment response. Research limitations and future clinical prospects are also discussed.

PTSD: from neurobiology to pharmacological treatments

Posttraumatic stress disorder (PTSD) is a chronic debilitating psychiatric disorder characterized by symptoms of re-experience, avoidance, and hyperarousal that can arise immediately or many years after exposure to a traumatic event and injury. Although extensive research has been done over the past 30 years, the etiology of PTSD remains largely unknown. Several neurobiological systems have been implicated in the pathophysiology and vulnerability for developing PTSD; however, first-line pharmacotherapies are limited. Less than 30% achieve full remission, and even then, approved pharmacological treatments often take weeks for therapeutic effect. This article aims to review the pathophysiology of PTSD within multiple neurobiological systems and how these mechanisms are used as pharmacologic targets of treatment, as well as their potential for future targets of intervention.

Exposure to emotionally arousing, contamination-relevant pictorial stimuli interferes with response inhibition: Implication for obsessive-compulsive disorder

Multiple emotional processes are implicated in the pathogenesis of obsessions and compulsions and individuals diagnosed with obsessive-compulsive disorder (OCD) have reliably shown deficits in response inhibition. Little research has tested how emotional processes might interact with cognitive control in the context of OCD. High contamination obsessive-compulsive (OC) and low contamination-OC participants completed an emotional go/no-go task to measure the interfering effects contamination-threat images relative to neutral images on action restraint (errors of commission). Results revealed that high contamination-OC participants committed marginally more commission errors (11.04%) than low contamination-OC participants (10.30%) on neutral no-go trials, but this effect was not significant (p > .05). All participants committed significantly more errors of commission on contamination-threat trails relative to neutral no-go trials, p < .01, but the interfering effects of contamination-threat images was significantly larger (p = .05) for high-contamination-OC participants. Errors of commission almost doubled for high contamination-OC participants on contamination-threat no-go trials (20.78%), compared to a more modest increase for low contamination-OC participants (14.80%). These findings suggest that individuals with elevated symptoms of OCD may have significantly more difficulty inhibiting their actions when processing disorder relevant or emotionally arousing information. This observation has implications for the pathogenesis of obsessions and compulsions.

Assessing Sexually Intrusive Thoughts: Parsing Unacceptable Thoughts on the Dimensional Obsessive-Compulsive Scale

Sexual obsessions are a common symptom of obsessive-compulsive disorder (OCD), often classified in a broader symptom dimension that includes aggressive and religious obsessions, as well. Indeed, the Dimensional Obsessive-Compulsive Scale (DOCS) Unacceptable Thoughts Scale includes obsessional content relating to sexual, violent, and religious themes associated with rituals that are often covert. However, there is reason to suspect that sexual obsessions differ meaningfully from other types of unacceptable thoughts. We conducted two studies to evaluate the factor structure, initial psychometric characteristics, and associated clinical features of a new DOCS scale for sexually intrusive thoughts (SIT). In the first study, nonclinical participants (N=475) completed the standard DOCS with additional SIT questions and we conducted an exploratory factor analysis on all items and examined clinical and cognitive correlates of the different scales, as well as test-retest reliability. The SIT Scale was distinct from the Unacceptable Thoughts Scale and was predicted by different obsessional cognitions. It had good internal consistency and there was evidence for convergent and divergent validity. In the second study, we examined the relationships among the standard DOCS and SIT scales, as well as types of obsessional cognitions and symptom severity, in a clinical sample of individuals with OCD (N=54). There were indications of both convergence and divergence between the Unacceptable Thoughts and SIT scales, which were strongly correlated with each other. Together, the studies demonstrate the potential utility of assessing sexually intrusive thoughts separately from the broader category of unacceptable thoughts.

Disgust and the politics of sex: exposure to a disgusting odorant increases politically conservative views on sex and decreases support for gay marriage

Disgust has been implicated as a potential causal agent underlying socio-political attitudes and behaviors. Several recent studies have suggested that pathogen disgust may be a causal mechanism underlying social conservatism. However, the specificity of this effect is still in question. The present study tested the effects of disgust on a range of policy preferences to clarify whether disgust is generally implicated in political conservatism across public policy attitudes or is uniquely related to specific content domains. Self-reported socio-political attitudes were compared between participants in two experimental conditions: 1) an odorless control condition, and 2) a disgusting odor condition. In keeping with previous research, the present study showed that exposure to a disgusting odor increased endorsement of socially conservative attitudes related to sexuality. In particular, there was a strong and consistent link between induced disgust and less support for gay marriage.

Disgust mediates the relation between attentional shifting and contamination aversion

BACKGROUND AND OBJECTIVES

Aversion of contaminants is important for several psychiatric disorders, particularly contamination-based obsessive-compulsive disorder (OCD). Recent theoretical models have proposed that the ability to control one's attention, especially when processing affectively laden information, is important in the etiology of pathological anxiety. The present study tested the relations between attentional control, affective arousal, and behavioral approach toward contaminants (contamination aversion).

METHODS

Thirty-three non-selected (undergraduate university students) participants completed a measure of trait attentional control and three behavioral approach tasks, which measured emotional reactivity and approach toward contaminants.

RESULTS

Preliminary analyses showed that poorer attentional control and greater affective arousal predicted less behavioral approach toward contaminants. Modeling of direct and indirect relations showed that poor attentional shifting ability and greater subjective disgust were related to less behavioral approach. Moreover, disgust fully mediated the relation between attentional shifting and behavioral approach.

LIMITATIONS

The present study used a convenience sample, which is not representative of the general population or individuals with OCD; therefore, research using clinical samples is necessary before making clinical interpretations. Moreover, the present study utilized subjective measures of attentional control and affective arousal. The use of objective measures of attention and affective arousal would provide a more valid test of the role of attentional control in contamination aversion.

CONCLUSIONS

These findings suggest that attentional shifting abilities may serve as a vulnerability to affective arousal/regulation and behavioral avoidance of contaminants, but the latter relation only operated indirectly via disgust. These findings have clear implications for the etiology of contamination-related OCD.

Specificity of fear and disgust experienced during traumatic interpersonal victimization in predicting posttraumatic stress and contamination-based obsessive-compulsive symptoms

Emerging evidence has documented comorbidity between posttraumatic stress disorder (PTSD) and obsessive-compulsive disorder (OCD) among individuals with a history of traumatic events. There is growing recognition of the importance of disgust in each of these conditions independently. No study, however, has examined the potential role of disgust in these conditions following traumatic event exposure. The current study examined the unique role of peritraumatic fear, self-focused disgust, and other-focused disgust in predicting posttraumatic stress symptoms and contamination-based OC symptoms among 49 adult women (M(age)=28.37, SD=13.86) with a history of traumatic interpersonal victimization. Results demonstrated that intensity of peritraumatic self-focused disgust was significantly related to contamination-based OC symptoms while peritraumatic fear and other-focused disgust were related to posttraumatic stress symptoms. These results highlight the need for future research aimed at elucidating the nature of the association between disgust experienced during traumatic events and subsequent psychopathology.

Obsessive beliefs predict cognitive behavior therapy outcome for obsessive compulsive disorder

Cognitive accounts of obsessive compulsive disorder (OCD) assert that core beliefs are crucial to the development, maintenance, and treatment of the disorder. There are a number of obsessive beliefs that are considered fundamental to OCD, including personal responsibility, threat estimation, perfectionism, need for certainty, importance of thoughts, and thought control. The present study investigated if pretreatment severity of obsessive beliefs, as well as the change in obsessive beliefs following treatment, predicted intensive, residential cognitive behavioral therapy (CBT) treatment outcome. A series of hierarchical regression analyses were carried out to investigate the relations between obsessive beliefs and treatment outcome. Results indicated that inflated pretreatment responsibility/threat estimation beliefs were significantly related to less overall obsessive compulsive (OC) symptom reduction at discharge, explaining 2% of the overall variance. Changes in obsessive beliefs broadly, and importance/control of thoughts specifically, were positively related to overall OC symptom reduction at discharge, respectively explaining 18% and 3.6% variance. Results are modestly consistent with a number of theoretical models, which argue that inflated responsibility, threat estimation, and thought control are important to the maintenance and treatment of OCD.

The emotional Stroop task and posttraumatic stress disorder: a meta-analysis

Posttraumatic stress disorder (PTSD) is associated with significant impairment and lowered quality of life. The emotional Stroop task (EST) has been one means of elucidating some of the core deficits in PTSD, but this literature has remained inconsistent. We conducted a meta-analysis of EST studies in PTSD populations in order to synthesize this body of research. Twenty-six studies were included with 538 PTSD participants, 254 non-trauma exposed control participants (NTC), and 276 trauma exposed control participants (TC). PTSD-relevant words impaired EST performance more among PTSD groups and TC groups compared to NTC groups. PTSD groups and TC groups did not differ. When examining within-subject effect sizes, PTSD-relevant words and generally threatening words impaired EST performance relative to neutral words among PTSD groups, and only PTSD-relevant words impaired performance among the TC groups. These patterns were not found among the NTC groups. Moderator analyses suggested that these effects were significantly greater in blocked designs compared to randomized designs, toward unmasked compared to masked stimuli, and among samples exposed to assaultive traumas compared to samples exposed to non-assaultive traumas. Theoretical and clinical implications are discussed.

Contamination aversion and repeated exposure to disgusting stimuli

Recent research has highlighted the central role of disgust in the etiology and maintenance of contamination aversion (CA). Data would also suggest that, although amendable to the treatment of choice for CA (exposure and response prevention [ERP]), disgust is resistant to habituation. However, with regard to CA, it is not yet known if disgust's resistance to habituation is an artifact of the emotion or the disorder. Specifically, research has not yet indicated if severity of CA moderates the effect of ERP on disgust. Utilizing an undergraduate convenience sample (n=33), the present study compared emotional responding (disgust and fear) with repeated exposure to a disgusting contamination-relevant stimulus between participants who are high in contamination aversion (HCA; n=17) and low in contamination aversion (LCA; n=16). Results indicated that, habituation of disgust was slower than fear within the HCA group but not the LCA group. Contrasts revealed that the decay of fear across trials was faster for HCA participants when compared with LCA participants, although decay of disgust was similar between groups. These results indicate that habituation of disgust is slower than fear when elevated CA is present.

Unique affective and cognitive processes in contamination appraisals: Implications for contamination fear

A large body of evidence suggests an important role of disgust in contamination fear (CF). A separate line of research implicates various cognitive mechanisms in contamination fear, including obsessive beliefs, memory biases, and delayed attentional disengagement from threat. This study is an initial attempt to integrate these two lines of research and examines whether disgust and delayed attention disengagement from threat explain unique or overlapping processes within CF. Non-clinical undergraduate students (N = 108) completed a spatial cueing task, which provided measures of delayed disengagement from frightening and disgusting cues, and a self-report measure of disgust propensity (DP). Participants also completed a chain of contagion task, in which they provided contamination appraisals of an object as a function of degrees of removal from an initial contaminant. Results demonstrated that DP predicted greater initial contamination appraisals, but a sharper decline in estimations across further degrees of removal from the contaminant. Delayed disengagement from disgust cues uniquely predicted sustained elevations in contamination estimations across further degrees of removal from the contaminant. These results suggest that DP and delayed disengagement from disgust cues explain unique and complimentary processes in contamination appraisals, which suggests the utility of incorporating the disparate affective and cognitive lines of research on CF.