Clinical trial NCT03095482: tDCS-Augmented Exposure Therapy for Pathological Fear
Official title: tDCS-Augmented Exposure Therapy for Pathological Fear
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Specific Phobias
Keywords: Arachnophobia (fear of spiders)
Ophidophobia (fear of snakes)
Germaphobia (fear of germs, dirtiness, and contamination)
Lead sponsor: University of Texas at Austin
Sponsor class: OTHER
First posted: 2017-03-29
Enrollment: 49
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Participants will be randomly assigned to receive either (a) excitatory tDCS of the medial prefrontal cortex and inhibitory tDCS of right dorsolateral prefrontal cortex, or (b) sham tDCS
Primary purpose: TREATMENT

Brief summary: This double-blind randomized controlled clinical trial aims to test whether transcranial direct current stimulation (tDCS) can be used to modulate fear extinction learning during exposure therapy for pathological fear, including fear of spiders, snakes, or germs / contamination. Participation takes place over three laboratory visits, including (1) a pre-treatment visit, (2) a treatment and post-treatment visit, and (3) a 1 month follow-up visit. During treatment, participants will receive either 20 minutes of active or sham tDCS, followed by 30 minutes of in vivo exposure therapy.

Detailed description: In a trans-diagnostic sample with marked pathological fear and behavioral avoidance, this study aims to: (1) evaluate whether excitatory tDCS of the mPFC and inhibitory tDCS of right dlPFC enhances exposure therapy relative to sham tDCS; (2) determine whether tDCS effects are moderated by baseline negative prognostic indicators; and (3) determine whether tDCS effects are mediated by pre-post changes in vigilance to threat, in-session fear reduction, and contextual memory for the exposure context. If successful, the project may discover a potentially effective exposure therapy augmentation, and may enhance knowledge of the behavioral, cognitive, affective, and neurobiological factors that moderate and mediate acute treatment response and maintenance of treatment gains. This knowledge may inform treatment development efforts for more debilitating forms of pathological fear.

Eligibility criteria: Inclusion Criteria:

1. Age 18-65.
2. Fluent in English.
3. A score on at least 1 fear domain-specific prescreen measure \> 2 SDs above the subject pool prescreen mean. These measures include (a) FSQ, and (b) OCI-R.
4. Peak fear ≥ 50 on BATs 1 and 2.

Exclusion Criteria:

1. Currently receiving treatment for the primary fear domain (based on clinical interview).
2. Unstable dose of psychotropic medications within 6 weeks prior to baseline assessment (based on the DMQ; see measures).
3. Medical condition that would contraindicate participation in treatment or assessment activities (e.g., cardiovascular problems; based on the DMQ; see measures).
4. Pregnancy (based on the DMQ; see measures).
5. Current major depressive disorder (based on MINI; see measures).
6. Current, or history of bipolar disorder (based on MINI; see measures).
7. Current, or history of psychotic symptoms (based on MINI; see measures).
8. Serious suicidal risk, as determined by self-report (C-SSRS, BDI-II) and clinical interview (MINI; see measures).
9. Active neurological conditions, including seizures, stroke, unexplained loss of consciousness or concussion (based on DMQ and tDCS Safety Screening Form; see measures)
10. Contraindications for tDCS: Metal in the head or implanted brain medical devices.

Primary outcomes:
measure: Change in peak fear during two behavioral approach tasks across time-points.
timeFrame: Pre-treatment (baseline), post-treatment (1 week later), and follow-up (1 month after treatment)
measure: Change in approach level during two behavioral approach tasks across time points.
timeFrame: Pre-treatment (baseline), post-treatment (1 week later), and follow-up (1 month after treatment)
Secondary outcomes:
measure: Change in arachnophobia symptom severity across time-points
timeFrame: Pre-treatment (baseline), post-treatment (1 week later), and follow-up (1 month after treatment)
measure: Change in ophidophobia symptom severity across time-points
timeFrame: Pre-treatment (baseline), post-treatment (1 week later), and follow-up (1 month after treatment)
measure: Change in germaphobia / contamination fear symptom severity across time points.
timeFrame: Pre-treatment (baseline), post-treatment (1 week later), and follow-up (1 month after treatment)
measure: Threat vigilance task
timeFrame: Before and after tDCS administration (1 week after baseline)
measure: Visuospatial working memory task
timeFrame: Before and after tDCS administration (1 week after baseline)
measure: Incidental contextual memory task
timeFrame: Stimulus presented during in vivo exposure (1 week after baseline), and memory assessed at follow-up (1 month after treatment)
Other outcomes:
Locations:
city: Austin
country: United States
facility: Laboratory for the Study of Anxiety Disorders
state: Texas
Study officials:
affiliation: The University of Texas at Austin
name: Adam R. Cobb, Ph.D.
role: PRINCIPAL_INVESTIGATOR
affiliation: The University of Texas at Austin
name: Michael J. Telch, PhD
role: STUDY_DIRECTOR
References: