Two-year follow-up of trauma-focused cognitive behavior therapy for posttraumatic stress disorder in emergency service personnel: A randomized clinical trial

BACKGROUND

Emergency service personnel experience elevated rates of posttraumatic stress disorder (PTSD). There are few controlled trials for PTSD in this population, and none report longer term effects of treatment. This study evaluated the benefits of cognitive behavior therapy (CBT) for PTSD in emergency service personnel who received either brief exposure (CBT-B) to trauma memories or prolonged exposure (CBT-L) 2 years following treatment.

METHODS

One hundred emergency service personnel with PTSD were randomized to CBT-L, CBT-B, or Wait-List (WL). Following posttreatment assessment, WL participants were randomized to an active treatment. Participants randomized to CBT-L or CBT-B were assessed at baseline, posttreatment, 6-month, and 2-year follow-up. Both CBT conditions involved 12 weekly individual sessions comprising education, CBT skills building, imaginal exposure, in vivo exposure, cognitive restructuring, and relapse prevention. Reliving trauma memories occurred for 40 min per session in CBT-L and for 10 min in CBT-B.

RESULTS

At the 2-year follow-up, there were no differences in PTSD severity (Clinician Administered PTSD Scale) between CBT-L and CBT-B. There were very large effect sizes for CBT-L (1.28, 95% confidence interval [CI] = 0.90-1.64) and CBT-B (1.28, 95% CI = 0.05-1.63) from baseline to 2-year follow-up.

CONCLUSIONS

This study highlights that CBT can be an effective treatment of PTSD in emergency service personnel using either prolonged or brief periods of reliving the trauma memory, and that these benefits can last for at least 2 years after treatment.

Developing an integrated intervention to address intimate partner violence and psychological distress in Congolese refugee women in Tanzania

BACKGROUND

Multi-sectoral, integrated interventions have long been recommended for addressing mental health and its social determinants (e.g., gender-based violence) in settings of ongoing adversity. We developed an integrated health and protection intervention to reduce psychological distress and intimate partner violence (IPV), and tested its delivery by lay facilitators in a low-resource refugee setting.

METHODS

Formative research to develop the intervention consisted of a structured desk review, consultation with experts and local stakeholders (refugee incentive workers, representatives of humanitarian agencies, and clinical experts), and qualitative interviews (40 free list interviews with refugees, 15 key informant interviews). Given existing efforts by humanitarian agencies to prevent gender-based violence in this particular refugee camp, including with (potential) perpetrators, we focused on a complementary effort to develop an integrated intervention with potential to reduce IPV and associated mental health impacts with female IPV survivors. We enrolled Congolese refugee women with elevated psychological distress and past-year histories of IPV (n = 60) who received the intervention delivered by trained and supervised lay refugee facilitators. Relevance, feasibility and acceptability of the intervention were evaluated through quantitative and qualitative interviews with participants. We assessed instrument test-retest reliability (n = 24), inter-rater reliability (n = 5 interviews), internal consistency, and construct validity (n = 60).

RESULTS

We designed an 8-session intervention, termed Nguvu ('strength'), incorporating brief Cognitive Processing Therapy (focused on helping clients obtaining skills to overcome negative thoughts and self-perceptions and gain control over the impact these have on their lives) and Advocacy Counseling (focused on increasing autonomy, empowerment and strengthening linkages to community supports). On average, participants attended two-thirds of the sessions. In qualitative interviews, participants recommended adaptations to specific intervention components and provided recommendations regarding coordination, retention, safety concerns and intervention participation incentives. Analysis of the performance of outcome instruments overall revealed acceptable reliability and validity.

CONCLUSIONS

We found it feasible to develop and implement an integrated, multi-sectoral mental health and IPV intervention in a refugee camp setting. Implementation challenges were identified and may be informative for future implementation and evaluation of multi-sectoral strategies for populations facing ongoing adversity.

TRIAL REGISTRATION

ISRCTN65771265, June 27, 2016.

Efficacy of exposure-based cognitive behaviour therapy for post-traumatic stress disorder in emergency service personnel: a randomised clinical trial

BACKGROUND

Although emergency service personnel experience markedly elevated the rates of post-traumatic stress disorder (PTSD), there are no rigorously conducted trials for PTSD in this population. This study assessed the efficacy of cognitive behaviour therapy (CBT) for PTSD in emergency service personnel, and examined if brief exposure (CBT-B) to trauma memories is no less efficacious as prolonged exposure (CBT-L).

METHOD

One hundred emergency service personnel with PTSD were randomised to either immediate CBT-L, CBT-B or wait-list (WL). Following post-treatment assessment, WL participants were randomised to an active treatment. Participants randomised to CBT-L or CBT-B were assessed at baseline, post-treatment and at 6-month follow-up. Both CBT conditions involved 12 weekly individual sessions comprising education, CBT skills building, imaginal exposure, in vivo exposure, cognitive restructuring and relapse prevention. Imaginal exposure occurred for 40 min per session in CBT-L and for 10 min in CBT-B.

RESULTS

At post-treatment, participants in WL had smaller reductions in PTSD severity (Clinician Administered PTSD Scale), depression, maladaptive appraisals about oneself and the world, and smaller improvements on psychological and social quality of life than CBT-L and CBT-B. There were no differences between CBT-L and CBT-B at follow-up on primary or secondary outcome measures but both CBT-L and CBT-B had large baseline to follow-up effect sizes for reduction of PTSD symptoms.

CONCLUSIONS

This study highlights that CBT, which can include either long or brief imaginal exposure, is efficacious in reducing PTSD in emergency service personnel.

Treating Prolonged Grief Disorder: A 2-Year Follow-Up of a Randomized Controlled Trial

BACKGROUND

Prolonged grief disorder (PGD) causes significant impairment in approximately 7% of bereaved people. Although cognitive-behavioral therapy (CBT) has been shown to effectively treat PGD, there is no evidence of long-term effects of CBT.

OBJECTIVE

To determine the long-term efficacies of CBT with exposure or CBT without exposure in treating PGD by assessing outcome at 2 years.

METHODS

A randomized controlled trial of PGD patients (N = 80) attending an outpatient clinic took place between September 2007 and June 2010, and a 2-year follow-up occurred between December 2009 and October 2012. All patients received 10 weekly 2-hour group therapy sessions that comprised CBT techniques. Patients also received 4 individual sessions in which they were randomly allocated to receive exposure therapy (CBT/Exposure) for memories of the death or supportive counseling (CBT). Prolonged grief disorder was assessed by clinical interview using the Complicated Grief Assessment. Severity of PGD, the primary outcome, was assessed using the Inventory of Complicated Grief.

RESULTS

Intent-to-treat analyses indicated a significant linear time × treatment condition interaction effect at 2 years (B = -0.63; SE = 0.26; t₂₂₅ = -2.44; P = .02; 95% CI, -1.14 to -0.12), indicating that CBT/Exposure led to greater reductions in PGD than CBT. Further, the linear between-group effect size at the 2-year follow-up was 1.15.

CONCLUSIONS

Exposure therapy in the course of CBT leads to greater reduction in symptoms of PGD than CBT without exposure, and this additive gain extends 2 years after treatment is complete. To achieve optimal treatment gains in patients with PGD, therapists should encourage some form of exposure therapy to memories of the death.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry identifier: ACTRN12609000229279.

A controlled trial of trauma-focused therapy versus problem-solving in Islamic children affected by civil conflict and disaster in Aceh, Indonesia

OBJECTIVE

To evaluate the relative efficacies of trauma-focused cognitive behavior therapy and problem-solving therapy in treating post-traumatic stress disorder in children affected by civil conflict in Aceh, Indonesia.

METHOD

A controlled trial of children with post-traumatic stress disorder ( N = 64) randomized children to either five individual weekly sessions of trauma-focused cognitive behavior therapy or problem-solving therapy provided by lay-counselors who were provided with brief training. Children were assessed by blind independent assessors at pretreatment, posttreatment and 3-month follow-up on post-traumatic stress disorder, depression and anger, as well as caregiver ratings of the child's post-traumatic stress disorder levels.

RESULTS

Intent-to-treat analyses indicated no significant linear time × treatment condition interaction effects for post-traumatic stress disorder at follow-up ( t(129.05) = -0.55, p = 0.58), indicating the two conditions did not differ. Across both conditions, there were significant reductions in post-traumatic stress disorder on self-reported ( t(131.26) = -9.26, p < 0.001) and caregiver-reported ( t(170.65) = 3.53, p = 0.001) measures and anger ( t(127.66) = -7.14, p < 0.001). Across both conditions, there was a large effect size for self-reported post-traumatic stress disorder (cognitive behavior therapy: 3.73, 95% confidence interval = [2.75, 3.97]; problem-solving: 2.68, 95% confidence interval = [2.07, 3.29]).

CONCLUSIONS

These findings suggest that trauma-focused cognitive behavior therapy and problem-solving approaches are comparably successful in reducing post-traumatic stress disorder and anger in treating mental health in children in a post-conflict setting. This pattern may reflect the benefits of non-specific therapy effects or gains associated with trauma-focused or problem-solving approaches.

Pre-Migration Trauma Exposure and Mental Health Functioning among Central American Migrants Arriving at the US Border

In recent years, increasing numbers of families and individuals have arrived at the U.S. border from Central America, in particular, from Honduras, El Salvador, and Guatemala. This study sought to examine pre-migration trauma exposure and current mental health functioning of migrant families arriving at the U.S. border from the Northern Triangle region, with specific attention to the reasons offered for leaving their home country and the frequency with which migrant families appear to satisfy legal criteria for asylum We interviewed 234 adults in McAllen, Texas, using a structured interview and standardized questionnaires to assess exposure to trauma prior to migration, reasons for leaving their home country and symptoms of posttraumatic stress and depression. We found that 191 participants (83%) cited violence as a reason for fleeing their country, 119 individuals (69%) did not report the events to the police out of fear of gang-related retaliation or police corruption, and 90% (n = 204) reported being afraid to return to their native country. Based on self-report symptom checklists, 32% of the sample met diagnostic criteria for PTSD (n = 51), 24% for depression (n = 36), and 17% for both disorders (n = 25). Examining these data against the criteria for asylum in the U.S., we found that 70% of the overall sample (n = 159) met criteria for asylum, including 80% of those from El Salvador, 74% from Honduras, and 41% from Guatemala. These findings suggest that the majority of Central American migrants arriving at the U.S. border have significant mental health symptoms in response to violence and persecution, and warrant careful consideration for asylum status.

Predictors of treatment response for cognitive behaviour therapy for prolonged grief disorder

Background: Prolonged grief disorder (PGD) causes significant impairment in approximately 7% of bereaved people. Although cognitive behaviour therapy (CBT) has been shown to effectively treat PGD, there is a need to identify predictors of treatment non-response. Methods: PGD patients (N = 80) were randomly allocated to receive 10 weekly two-hour group CBT sessions and (a) four individual sessions of exposure therapy or (b) CBT without exposure. PGD was assessed by self-report measures at baseline, post-treatment (N = 61), and six-months (N = 56) after treatment. Results: Post-treatment assessments indicated that greater reduction in grief severity relative to pretreatment levels was associated with being in the CBT/Exposure condition, and lower baseline levels of self-blame and avoidance. At follow-up, greater grief symptom reduction was associated with being in the CBT/Exposure condition and lower levels of avoidance. Conclusions: These patterns suggest that strategies that target excessive self-blame and avoidance during treatment may enhance response to grief-focused cognitive behaviour therapy.

Enhancing self-efficacy improves episodic future thinking and social-decision making in combat veterans with posttraumatic stress disorder

Posttraumatic Stress Disorder (PTSD) is associated with maladaptive changes in self-identity, including impoverished perceived self-efficacy. This study examined if enhancing perceptions of self-efficacy in combat veterans with and without symptoms of PTSD promotes cognitive strategies associated with positive mental health outcomes. Prior to completing a future thinking and social problem-solving task, sixty-two OEF/OIF veterans with and without symptoms of PTSD were randomized to either a high self-efficacy (HSE) induction in which they were asked to recall three autobiographical memories demonstrating self-efficacy or a control condition in which they recalled any three autobiographical events. An interaction between HSE and PTSD revealed that individuals with symptoms of PTSD in the HSE condition generated future events with more self-efficacious statements than those with PTSD in the control condition, whereas those without PTSD did not differ in self-efficacy content across the conditions. In addition, individuals in the HSE condition exhibited better social problem solving than those in the control condition. Increasing perceptions of self-efficacy may promote future thinking and problem solving in ways that are relevant to overcoming trauma and adversity.

Predictors of suicidal ideation in treatment-seeking survivors of torture

In this study, we examined sociodemographic, persecutor identity, torture, and postmigration variables associated with suicidal ideation in a clinical sample of 267 immigrant survivors of torture who have resettled in New York City. The purpose of this study was to identify variables associated with increased risk for suicidal ideation in survivors of torture before they receive legal, psychological, or medical services for torture-related needs. Results from a binary logistic regression model identified a combination of 3 variables associated with current suicidal ideation at intake into the program. Being female, having not submitted an application for asylum, and a history of rape or sexual assault were significantly associated with suicidal ideation at intake, when also controlling for several other important variables. The final model explained 21.4% of variation in reported suicidal ideation at intake. The discussion will focus on the importance of conducting a thorough assessment of suicidal ideation in refugees and survivors of torture.

Treating prolonged grief disorder: a randomized clinical trial

IMPORTANCE

Prolonged grief disorder (PGD) is a potentially disabling condition that affects approximately 10% of bereaved people. Grief-focused cognitive behavior therapy (CBT) has been shown to be effective in treating PGD. Although treatments for PGD have focused on exposure therapy, much debate remains about whether exposure therapy is optimal for PGD.

OBJECTIVE

To determine the relative efficacies of CBT with exposure therapy (CBT/exposure) or CBT alone for PGD.

DESIGN, SETTING, AND PARTICIPANTS

A randomized clinical trial of 80 patients with PGD attending the outpatient University of New South Wales Traumatic Stress Clinic from September 17, 2007, through June 7, 2010.

INTERVENTIONS

All patients received 10 weekly 2-hour group therapy sessions that consisted of CBT techniques. Patients also received 4 individual sessions, in which they were randomized to receive exposure therapy for memories of the death or supportive counseling.

MAIN OUTCOMES AND MEASURES

Measures of PGD by clinical interview and self-reported measures of depression, cognitive appraisals, and functioning at the 6-month follow-up.

RESULTS

Intention-to-treat analyses at follow-up indicated a significant quadratic time×treatment condition interaction effect (B [SE], 0.49 [0.16]; t120.16=3.08 [95% CI, 0.18-0.81]; P=.003), indicating that CBT/exposure led to greater PGD reductions than CBT alone. At follow-up, CBT/exposure led to greater reductions in depression (B [SE], 0.35 [0.12]; t112.65=2.83 [95% CI, 0.11-0.60]; P=.005), negative appraisals (B [SE], 0.68 [0.25]; t109.98=2.66 [95% CI, 0.17-1.18]; P=.009), and functional impairment (B [SE], 0.24 [0.08]; t111.40=3.01 [95% CI, 0.08-0.40]; P=.003) than CBT alone. In terms of treatment completers, fewer patients in the CBT/exposure condition at follow-up (14.8%) met criteria for PGD than those in the CBT condition (37.9%) (odds ratio, 3.51; 95% CI, 0.96-12.89; χ2=3.81; P=.04).

CONCLUSIONS AND RELEVANCE

Including exposure therapy that promotes emotional processing of memories of the death is an important component to achieve optimal reductions in PGD severity. Facilitating emotional responses to the death may promote greater changes in appraisals about the loss, which are associated with symptom reduction. Promotion of emotional processing techniques in therapies to treat patients with PGD is needed.

TRIAL REGISTRATION

anzctr.org.au Identifier: ACTRN12609000229279.

Posttraumatic stress in emergency settings outside North America and Europe: a review of the emic literature

Mental health professionals from North America and Europe have become common participants in postconflict and disaster relief efforts outside of North America and Europe. Consistent with their training, these practitioners focus primarily on posttraumatic stress disorder (PTSD) as their primary diagnostic concern. Most research that has accompanied humanitarian aid efforts has likewise originated in North America and Europe, has focused on PTSD, and in turn has reinforced practitioners' assumptions about the universality of the diagnosis. In contrast, studies that have attempted to identify how local populations conceptualize posttrauma reactions portray a wide range of psychological states. We review this emic literature in order to examine differences and commonalities across local posttraumatic cultural concepts of distress (CCDs). We focus on symptoms to describe these constructs - i.e., using the dominant neo-Kraepelinian approach used in North American and European psychiatry - as opposed to focusing on explanatory models in order to examine whether positive comparisons of PTSD to CCDs meet criteria for face validity. Hierarchical clustering (Ward's method) of symptoms within CCDs provides a portrait of the emic literature characterized by traumatic multifinality with several common themes. Global variety within the literature suggests that few disaster-affected populations have mental health nosologies that include PTSD-like syndromes. One reason for this seems to be the almost complete absence of avoidance as pathology. Many nosologies contain depression-like disorders. Relief efforts would benefit from mental health practitioners getting specific training in culture-bound posttrauma constructs when entering settings beyond the boundaries of the culture of their training and practice.

The impact of perceived self-efficacy on memory for aversive experiences

Self-efficacy is a key construct underlying healthy functioning and emotional well-being. Perceptions of uncontrollability, unpredictability, and low self-efficacy are consistently associated with negative mental health outcomes, such as post-traumatic stress disorder (PTSD). To test the causal relation between perceived coping self-efficacy and stress responses we employed a trauma film paradigm in which college students (N=33) viewed a graphic film of the aftermath of a motor vehicle accident following a high (HSE) or low self-efficacy (LSE) induction. Participants were tested for intrusions, distress, and memory recall for the film over the following 24 hours. LSE participants recalled more central details than HSE participants. Further, HSE participants reported fewer negative intrusions immediately following the film and at 24 hours. These findings suggest that strategies that increase perceived coping self-efficacy may reduce intrusive recollections of an aversive event, and also reduce the attentional bias associated with remembering aversive stimuli.

Fear of memories: the nature of panic in posttraumatic stress disorder

BACKGROUND

Although there is increasing evidence that panic attacks are common in posttraumatic stress disorder (PTSD), little is known if posttraumatic panic is comparable to panic attacks observed in panic disorder (PD).

OBJECTIVE

This study examined the cognitive responses to panic attacks in participants with PD and PTSD.

METHOD

Participants with PD (n=22) and PTSD (n=18) were assessed on the Anxiety Disorder Interview Schedule for DSM-IV and subsequently administered the Agoraphobic Cognitions Questionnaire and a measure of fears related to trauma memories.

RESULTS

Although participants did not differ in terms of catastrophic appraisals about somatic sensations, PTSD participants were more likely to experience fears about trauma memories and being harmed by trauma again during their panic attacks than PD participants.

CONCLUSIONS

These findings suggest that although PTSD participants fear somatic outcomes during panic attacks, their panic attacks are distinguished by a marked fear of trauma memories.

Amygdala in stroke/transient ischemic attack patients and its relationship to cognitive impairment and psychopathology: the Sydney Stroke Study

OBJECTIVE

To examine the structural abnormalities in the amygdala in stroke patients and see what contribution the amygdala may make to psychopathology and cognitive dysfunction related to stroke, because the amygdala has important roles in the processing of emotions, cognitive function, and psychiatric disorders.

METHODS

The authors assessed 47 stroke/transient ischemic attack (TIA) patients 3-6 months after the event and 54 comparison healthy subjects, using neuropsychological tests, medical and psychiatric examination and magnetic resonance imaging (MRI) brain scans. Volumetric T1-weighted MRI was used to obtain amygdala volumes by manual tracing.

RESULTS

Stroke/TIA patients had smaller right amygdalar volume, more white matter hyperintensities (WMHs), and larger lateral ventricles. The amygdala was smaller in stroke/TIA patients with cognitive impairment compared to those without impairment. The right amygdala volume was negatively correlated with visual new learning and not related to depression, anxiety, irritability, agitation or apathy at baseline or 12-month follow-up. However, baseline amygdala volume was negatively correlated with Hamilton depression scores at 12 months in healthy comparison subjects. Hypertension and atrial fibrillation, and to a lesser extent WMHs, were predictors of amygdala volume.

CONCLUSION

The amygdala is smaller in stroke/TIA patients, especially in those with cognitive impairment. This may partly be accounted for by hypertension, white matter lesions, and atrial fibrillation. It is not related to psychopathology except that small amygdalae may increase vulnerability to depression.

Hippocampal size and dementia in stroke patients: the Sydney stroke study

BACKGROUND

Hippocampal atrophy is an early feature of Alzheimer's disease (AD) but it has also been reported in vascular dementia (VaD). It is uncertain whether hippocampal size can help differentiate the two disorders.

METHODS

We assessed 90 stroke/TIA patients 3-6 months after the event, and 75 control subjects, with neuropsychological tests, medical and psychiatric examination and brain MRI scans. A diagnosis of VaD, vascular mild cognitive impairment (VaMCI) or no cognitive impairment (NCI) was reached by consensus on agreed criteria. T1-weighted MRI was used to obtain total intracranial volume (TICV), gray and white matter volume, CSF volume, hippocampus and amygdala volumes, and T2-weighted scans for white matter hyperintensity (WMH) ratings.

RESULTS

Stroke/TIA patients had more white matter hyperintensities (WMHs), larger ventricle-to-brain ratios and smaller amygdalae than controls, but hippocampus size and gray and white matter volumes were not different. WMHs and amygdala but not hippocampal volume distinguished stroke/TIA patients with VaD and VaMCI and without NCI and amygdala volumes. Right hippocampus volume significantly correlated with new visual learning.

CONCLUSIONS

Stroke/TIA patients and patients with post-stroke VaMCI or mild VaD do not have hippocampal atrophy. The amygdala is smaller in stroke/TIA patients, especially in those with cognitive impairment, and this may be accounted for by white matter lesions. The hippocampus volume relates to episodic memory, especially right hippocampus and new visual learning. A longitudinal study of these subjects will determine whether hippocampal atrophy is a late development in VaD.

Time and stimulus specificity in extinction of the conditioned nictitating membrane response in the rabbit (Oryctolagus cuniculus)

The present experiments demonstrated that, in the rabbit nictitating membrane preparation, a conditioned response (CR) can be selectively eliminated in one portion of a conditioned stimulus (CS) while it is still paired with the unconditioned stimulus (US). Rabbits were initially trained with two stimuli (tone, light). Each was paired with the US by using a mixture of two CS-US interstimulus intervals (ISIs): 200 ms and 1,200 ms in Experiment 1; 150 ms and 500 ms in Experiment 2. The CRs showed double peaks, one for each ISI. Subsequently, one CS (A) was trained with only the longer ISI, whereas the other CS (B) continued to be trained with both ISIs. Consequently, the CR peak based on the shorter ISI disappeared for CSA but not for CSB. The later CR peaks during both CSA and CSB were maintained. These results support time-based models of conditioning. Implications for proposed mechanisms of extinction are discussed.

Prediction of cognitive decline after stroke using proton magnetic resonance spectroscopy

Structural MRI measures have been used to predict cognitive decline in elderly subjects, but few studies have used proton magnetic resonance spectroscopy ((1)H-MRS) for this purpose, particularly after stroke. We studied the potential of (1)H-MRS to predict cognitive decline in patients with stroke or TIA and healthy ageing controls over 12 months and 3 years. Structural MRI and single-voxel (1)H-MRS in the frontal white matter and the occipito-parietal gray matter were performed at the index assessment (3-6 months post-stroke) in 49 stroke/TIA patients and 60 controls. Neuropsychological testing was performed at the index assessment and repeated at 12 months in 30 stroke/TIA patients and 49 controls, and at 3 years in 25 patients and 48 controls. In stroke/TIA patients, frontal NAA/Cr predicted cognitive decline over 12 months and 3 years, and in elderly control subjects frontal NAA predicted cognitive decline over 12 months only. In stroke/TIA patients, the (1)H-MRS measures were better predictors of cognitive decline than structural measures. (1)H-MRS may be useful in assessing early cognitive impairment after stroke/TIA and in normal ageing.

Temporally specific extinction of conditioned responses in the rabbit (Oryctolagus cuniculus) nictitating membrane preparation

Extinguishing a conditioned response (CR) has entailed separating the conditioned stimulus (CS) from the unconditioned stimulus (US). This research reveals that elimination of the rabbit (Oryctolagus cuniculus) nictitating membrane response occurred during continuous CS-US pairings. Initial training contained a mixture of 2 CS-US interstimulus intervals (ISIs): 200 ms and 1,200 ms. The CRs showed double peaks, one for each ISI. When 1 ISI was removed, its CR peak showed the hallmarks of extinction: a decline across sessions, spontaneous recovery between sessions, and rapid reacquisition when the absent ISI was reintroduced. These results support real-time models of conditioning that segment the CS into microstimuli while challenging theories that rely on contextual control, US representations, CS processing, and response inhibition.