Efficacy of Expectancy Focused Exposure Therapy in Reducing Fear and Preventing the Return of Anxiety Over Time: A Longitudinal Randomized Clinical Trial
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 203
- 试验地点
- 1
- 主要终点
- Change in standardized disorder-specific anxiety symptom severity
研究概览
简要总结
This clinical trial evaluates whether an optimized exposure-based treatment improves long-term outcomes for adults with anxiety disorders. Specifically, it examines whether Expectancy Focused Exposure (EFE), based on the inhibitory learning model, is more effective than Anxiety Focused Exposure (AFE) in reducing anxiety symptoms and preventing the return of fear over time. The study includes adults aged 18 years and older diagnosed with an anxiety disorder, including social anxiety disorder, specific phobia, generalized anxiety disorder, and panic disorder with or without agoraphobia. Anxiety disorders are highly prevalent and can significantly interfere with daily functioning, work performance, and interpersonal relationships. Exposure therapy is a central component of cognitive behavioral treatment for anxiety disorders. Traditional exposure approaches often focus on reducing anxiety during exposure sessions, but many individuals experience a return of fear after treatment. New theoretical models suggest that exposure may be more effective when designed to violate threat expectations and strengthen inhibitory learning. Participants will be recruited in sequential cohorts and randomly assigned to immediate treatment or a brief waitlist before treatment begins. Those assigned to the waitlist will start treatment at the next study step. When treatment begins, participants will receive either EFE or AFE. Both treatments consist of approximately 10 weekly individual psychotherapy sessions delivered by trained therapists. Participants will complete clinical assessments before treatment, during treatment, immediately after treatment, and at 6, 12, and 18 months after treatment completion. In AFE, exposure exercises are organized along an anxiety hierarchy and focus on reducing anxiety responses through repeated confrontation with feared stimuli. In EFE, exposure focuses on identifying and testing threat expectations, and exercises are designed to maximize expectancy violation and strengthen inhibitory learning. Potential risks include temporary emotional discomfort during exposure exercises. All sessions will be conducted by trained clinicians who monitor participant safety throughout the study. The results may help improve exposure-based treatments for anxiety disorders by identifying strategies that enhance long-term outcomes and reduce relapse.
详细描述
Anxiety disorders are highly prevalent worldwide and are a major source of disability and reduced quality of life. They involve excessive fear and anxiety, physiological activation, hypervigilance, and avoidance behaviors that interfere with social and occupational functioning. They include social anxiety disorder, specific phobia, generalized anxiety disorder, and panic disorder with or without agoraphobia. In Chile, anxiety disorders are a major public health concern, with estimated lifetime prevalence of approximately 16.2% in adults and 6-month prevalence of 7.9%. They are among the leading causes of years lived with disability, particularly among women, and recent reports suggest that approximately one in four Chileans presents anxiety symptoms. Chilean clinical guidelines recommend cognitive behavioral therapy (CBT) among the primary treatments.
CBT is a first-line treatment for anxiety disorders, and exposure therapy is its central component. Exposure involves systematic confrontation with feared stimuli or situations in the absence of the anticipated aversive outcome. Although effective, symptom reduction during treatment does not necessarily predict long-term maintenance, and return of fear remains common.
Experimental psychopathology has emphasized learning mechanisms underlying exposure. Extinction occurs when the feared stimulus is repeatedly encountered without the expected outcome. Rather than erasing the original fear association, extinction produces inhibitory learning that competes with the original fear memory. Because the original association remains intact, fear can reappear through renewal, spontaneous recovery, reinstatement, or rapid reacquisition.
Contemporary models propose that therapeutic change is better understood as inhibitory learning than habituation. A key mechanism is expectancy violation: the discrepancy between what individuals expect to occur during exposure and what actually occurs. Expectancy-focused approaches emphasize learning that feared outcomes are less likely, less intense, or less catastrophic than anticipated.
Randomized clinical evidence evaluating optimized exposure remains limited. Recent evidence suggests that inhibitory learning and expectancy violation may improve treatment response, but short follow-up periods may be insufficient to evaluate relapse or recurrence. This trial evaluates whether exposure focused on expectancy violation and inhibitory learning produces more durable improvements than exposure focused primarily on anxiety reduction, with outcomes assessed during treatment and at 6, 12, and 18 months.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Triple (Participant, Care Provider, Outcomes Assessor)
盲法说明
Participants and outcome assessor are blinded to treatment allocation. Therapists are aware of the intervention delivered but are not informed of the study hypothesis regarding the relative effectiveness of the treatments.
入排标准
- 年龄范围
- 18 Years 至 70 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Population Description The study sample will consist of adult participants from the general population seeking psychological treatment for anxiety-related problems. Participants will be recruited through multiple sources, including university mental health services, student wellbeing units, community mental health centers, social media advertisements, and other public outreach channels. Recruitment will be intentionally broad to maximize accessibility and ecological validity.
- •Screening and Selection Procedures Eligibility will be determined through a multi-stage screening process. Initial Screening: DSM-5 Cross-Cutting Measures, Levels 1 and 2 Participants responding to recruitment will first complete the DSM-5 Level 1 Cross-Cutting Symptom Measure (APA, 2013; Spanish version APA, 2014). This self-report instrument includes 23 items assessing 13 domains of psychopathology over the past 14 days using a 5-point Likert scale. It has shown good reliability and clinical utility in prior studies (APA, 2014; Bravo et al., 2018).
- •Participants who meet threshold criteria for anxiety-related symptoms on the Level 1 measure will then complete the corresponding DSM-5 Level 2 anxiety measures to further characterize symptom severity.
- •Disorder-Specific Symptom Assessment, Level 3 Participants who meet screening criteria on Levels 1 and 2 will complete disorder-specific symptom scales according to the anxiety disorder suspected or reported, including measures for social anxiety disorder, specific phobia, generalized anxiety disorder, and panic disorder with or without agoraphobia.
- •Diagnostic Assessment Participants who remain eligible after the screening and disorder-specific symptom assessment will undergo a structured clinical interview using the Anxiety and Related Disorders Interview Schedule for DSM-5 (ADIS-5). The ADIS-5 will be used to establish the principal anxiety disorder diagnosis and to assess
排除标准
- •, including psychotic disorder, bipolar disorder, high suicide risk, and severe or uncontrolled substance use disorder.
- •Inclusion Criteria:
- •Participants must meet all of the following criteria:
- •Age between 18 and 70 years.
- •Seeking treatment for anxiety-related difficulties.
- •Meet DSM-5 diagnostic criteria for a principal anxiety disorder, including:
- •social anxiety disorder, specific phobia, generalized anxiety disorder, panic disorder with or without agoraphobia.
- •Diagnosis will be established using the ADIS-5 structured clinical interview.
- •For participants with generalized anxiety disorder, treatment will focus on the principal anxiety problem identified during assessment.
- •Present clinically significant anxiety symptoms associated with the principal diagnosis.
- •If currently taking anxiolytic medication, the dosage must have remained stable for at least three months before the start of treatment and should be maintained during the treatment phase whenever possible.
- •Willingness and ability to participate in weekly psychotherapy sessions and complete all study assessments.
- •Provide informed consent.
- •Exclusion Criteria:
- •Participants will be excluded if any of the following conditions are present:
- •Current psychotic disorder.
- •Current manic or hypomanic episode, consistent with bipolar disorder.
- •High suicide risk requiring immediate clinical intervention.
- •Severe or uncontrolled substance use disorder.
- •Concurrent participation in psychological treatment specifically targeting the anxiety disorder during the study period.
- •Medical conditions that contraindicate exposure procedures (e.g., severe cardiovascular conditions).
- •Cognitive impairment or insufficient language proficiency that would interfere with participation in psychotherapy or completion of assessments.
研究组 & 干预措施
Expectancy Focused Exposure (EFE)
Exposure-based treatment designed to maximize expectancy violation and strengthen inhibitory learning.
干预措施: Expectancy Focused Exposure (Behavioral)
Anxiety Focused Exposure (AFE)
Traditional exposure therapy focused on gradual reduction of anxiety responses through repeated exposure.
干预措施: Anxiety Focused Exposure (Behavioral)
Waitlist
Participants assigned to the waitlist will not receive treatment for 12 weeks before starting one of the active interventions.
结局指标
主要结局
Change in standardized disorder-specific anxiety symptom severity
时间窗: Baseline; weekly during treatment through post-treatment assessment at session 10, up to 10 treatment sessions; and follow-up assessments at 6, 12, and 18 months after treatment completion.
Severity of the principal anxiety disorder will be assessed using one disorder-specific measure according to each participant's primary diagnosis: the Liebowitz Social Anxiety Scale for social anxiety disorder, the Severity Measure for Specific Phobia-Adult for specific phobia, the Generalized Anxiety Disorder 7-item Scale for generalized anxiety disorder, or the Panic and Agoraphobia Scale for panic disorder with or without agoraphobia. Each scale yields a total symptom severity score, with higher scores indicating greater anxiety severity. Score ranges are: Liebowitz Social Anxiety Scale, 0-72; Severity Measure for Specific Phobia-Adult, 0-40; Generalized Anxiety Disorder 7-item Scale, 0-21; and Panic and Agoraphobia Scale, 0-52. Raw total scores will be transformed into standardized z-scores before analysis. The reported outcome will be a single aggregated standardized z-score representing disorder-specific anxiety severity. Higher z-scores indicate greater symptom severity.
次要结局
- Change in general anxiety symptoms(Baseline; weekly during treatment through post-treatment assessment at session 10, up to 10 treatment sessions; and follow-up assessments at 6, 12, and 18 months after treatment completion.)
- Change in general psychological distress(Baseline; weekly during treatment through post-treatment assessment at session 10, up to 10 treatment sessions; and follow-up assessments at 6, 12, and 18 months after treatment completion.)
- Clinically significant change in standardized disorder-specific anxiety symptom severity(Baseline; weekly during treatment through post-treatment assessment at session 10, up to 10 treatment sessions; and follow-up assessments at 6, 12, and 18 months after treatment completion.)
- Recurrence of anxiety symptoms during follow-up(From post-treatment assessment through follow-up assessments at 6, 12, and 18 months after treatment completion.)