tDCS-Augmented Exposure Therapy for Pathological Fear

Specific Phobias Clinical Trial

Official title:

tDCS-Augmented Exposure Therapy for Pathological Fear

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03095482
• Other study ID #: 2016-02-0024
• Status: Completed
• Phase: N/A
• Start date: January 1, 2017
• Est. completion date: September 6, 2018

Study information

• Verified date: December 2020
• Source: University of Texas at Austin
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 49
• Est. completion date: September 6, 2018
• Est. primary completion date: September 6, 2018
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

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.

Related Conditions & MeSH terms

• Specific Phobias

Intervention

Device:
• Transcranial Direct Current Stimulation (tDCS)
Participants will receive 20 minutes of either active or sham tDCS prior to in vivo exposure to feared targets.

Behavioral:
• In vivo exposure therapy
Participants will receive 30 minutes of in vivo exposure to feared targets following either active or sham tDCS

Locations

Country	Name	City	State
United States	Laboratory for the Study of Anxiety Disorders	Austin	Texas

Sponsors (1)

Lead Sponsor	Collaborator
University of Texas at Austin

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in peak fear during two behavioral approach tasks across time-points.	Subjective units of distress from 0 = no fear, to 100 = extreme fear	Pre-treatment (baseline), post-treatment (1 week later), and follow-up (1 month after treatment)
Primary	Change in approach level during two behavioral approach tasks across time points.	Highest difficulty level achieved from 0 = least challenging to 10 = most challenging.	Pre-treatment (baseline), post-treatment (1 week later), and follow-up (1 month after treatment)
Secondary	Change in arachnophobia symptom severity across time-points	Total score on the Fear of Spiders Questionnaire	Pre-treatment (baseline), post-treatment (1 week later), and follow-up (1 month after treatment)
Secondary	Change in ophidophobia symptom severity across time-points	Total score on the Fear of Snakes Questionnaire	Pre-treatment (baseline), post-treatment (1 week later), and follow-up (1 month after treatment)
Secondary	Change in germaphobia / contamination fear symptom severity across time points.	Total score on the Obsessive Compulsive Inventory - Revised.	Pre-treatment (baseline), post-treatment (1 week later), and follow-up (1 month after treatment)
Secondary	Threat vigilance task	Computer-based task that assesses attention biases towards and away from threatening images.	Before and after tDCS administration (1 week after baseline)
Secondary	Visuospatial working memory task	Delayed match to sample task assessing recognition of 4 x 4 arrays of colored blocks, after a brief delay.	Before and after tDCS administration (1 week after baseline)
Secondary	Incidental contextual memory task	Assessment of incidental memory for a 4 x 4 array of line drawings from the Test of Memory Malingering, presented in the treatment context only during in vivo exposure.	Stimulus presented during in vivo exposure (1 week after baseline), and memory assessed at follow-up (1 month after treatment)

External Links

•   Website for the Laboratory for the Study of Anxiety Disorders