Effect of tDCS Timing on Safety Memory in PTSD

Butler Hospital

Status: Completed

Conditions: PTSD

Treatments: Device: transcranial direct current stimulation

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT04152772

P20GM130452 (U.S. NIH Grant/Contract)

1346426-5

Details and patient eligibility

About

The primary purpose of this study is to investigate the effects of tDCS timing on extinction memory in PTSD. A total of 90 participants will be randomized equally across one of three groups:

1. One group receiving active stimulation during extinction followed by sham stimulation during consolidation
2. One group receiving sham stimulation during extinction followed by active stimulation during consolidation
3. One group receiving sham stimulation both during extinction and consolidation

This study also includes an online sub-study (Aim 2) focused on contextual processing along the PTSD spectrum. The online study tests if there is an association between threat and non-threat learning in contextual and non-contextual situations. A maximum of 500 participants will be recruited using an online, panel-based platform.

Full description

This is a three-arm study composed of four to five visits over an approximate period of three weeks. Up to ninety participants are exposed to a fear conditioning, extinction, and extinction memory paradigm at three separate study visits (day 3-5); one of these study visits will include active or sham transcranial direct current stimulation (tDCS) for a period of 15 minutes. Skin conductance reactivity during extinction memory (day 5) is the primary outcome. Additional study procedures include a screening period (day 1) and two optional MRI scans, one done on study day 2 and one done on study day 5. As the completion of MRI scans are an optional study component, MRI-related data is not reported here.

SUB-STUDY: The objective of this sub-study is to test performance differences between contextual and non-contextual processing in individuals across the PTSD spectrum using an online, panel-based platform. Following a within-subjects study design, up to 500 adult participants, 18-89 years, will be asked to complete experimental tasks that assess contextual (configural) and non-contextual (elemental) threat and non-threat learning. They will also provide demographic information (age, sex, ethnicity) and complete questionnaires assessing self-reported PTSD, anxiety, and depression severity. As this sub-study does not reflect a randomized clinical trial (no groups, no randomization, no intervention), no further information is reported here.

Enrollment: 62 patients

Sex: All

Ages: 18 to 70 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Primary diagnosis of PTSD, assessed by the Structured Clinical Interview of DSM-5 (SCID);
2. aged 18-70;
3. ability to speak, read, write, and understand English sufficiently well to complete study procedures and provide informed consent;
4. Stable psychiatric medication use or treatment for at least 6 weeks.

Exclusion criteria

1. Lifetime history of psychotic or bipolar disorder;
2. Current moderate or severe substance use disorder; if mild, not under the influence at time of study participation;
3. Acute suicidal or homicidal ideation as detected on screening instruments or in the investigator team's opinion, is likely to attempt suicide within 6 months;
4. current (or past) significant neurological disorder, injury, or other intracranial pathology including severe traumatic brain injury or lifetime history of a) seizure disorder b) primary or secondary CNS tumors c) stroke or d) cerebral aneurysm;
5. lifetime history of moderate or, current unstable medical conditions;
6. Any problems that would interfere with study participation, including MRI- or tDCS-related contraindications (e.g., implanted metallic devices/substances, metallic tattoos, pregnancy, claustrophobia, holes in the skull, skin abnormalities under stimulation sites), or indication of colorblindness, or presence of any other condition or circumstance that, in the opinion of the investigator team, has the potential to prevent study completion and/or inability to schedule visit days within the allotted time, and/or to have a confounding effect on outcome assessments.

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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62 participants in 3 patient groups

Active tDCS during extinction learning followed by sham tDCS during consolidation

Active Comparator group

Description:

Active tDCS will be applied during the extinction learning phase followed by sham tDCS during the consolidation phase.

Treatment:

Device: transcranial direct current stimulation

Sham tDCS during extinction learning followed by active tDCS during consolidation

Active Comparator group

Description:

Sham tDCS will be applied during the extinction learning phase followed by active tDCS during the consolidation phase.

Treatment:

Device: transcranial direct current stimulation

Sham tDCS during extinction learning followed by sham tDCS during consolidation

Sham Comparator group

Description:

Sham tDCS will be applied during the extinction learning phase followed by sham tDCS during the consolidation phase.

Treatment:

Device: transcranial direct current stimulation