To test whether tACS in a theta frequency enhances extinction of physiological stress responses to exposure to anxiety- or trauma-related stimuli or memories. Secondarily, to examine the influence of baseline neuroendocrinological response, baseline…
ID
Source
Brief title
Condition
- Anxiety disorders and symptoms
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The primary study parameter is the stress response based on heart rate
variability (HRV) and subjective units of distress (SUDs) during the
exposure-based therapy sessions and subjective anxiety symptoms after the
exposure-based therapy sessions.
Secondary outcome
Secondary study parameters are PTSD symptom severity and the influence of
various baseline measures: resting-state heart rate variability, theta
electroencephalography (EEG) activity, emotional working memory, stress hormone
response, sleep quality and various mental health variables.
Background summary
The efficacy of treatments for trauma- and stressor-related disorders and
anxiety disorders can potentially be improved in an innovative way.
Evidence-based exposure therapies are aimed at extinguishing stress responses
to anxiety- or trauma-related stimuli (fear extinction). The proposed mechanism
behind this treatment is to weaken the fear memory and develop a safety memory,
by formation of a so-called updated *stimulus-no trauma* association. The
rationale behind this research proposal is that the administration of weak
electric currents strengthens the consolidation of the safety memory by
enhancing neural synchronization in the theta frequency (4-7 Hz), which plays
an important role in learning and memory. We hypothesize that applying
transcranial alternating current stimulation (tACS) in the theta frequency as
add-on to exposure therapy will enhance the consolidation of the safety memory
and ameliorates treatment outcome.
Study objective
To test whether tACS in a theta frequency enhances extinction of physiological
stress responses to exposure to anxiety- or trauma-related stimuli or memories.
Secondarily, to examine the influence of baseline neuroendocrinological
response, baseline resting state electroencephalogram (EEG) theta oscillations,
sleep, age and use of medication on the effectiveness of tACS as add-on to
treatment as usual (exposure therapy)
Study design
This is a double-blind placebo-controlled intervention study with an
experimental group (active tACS) and a control group (sham tACS). Participants
undergo a 6-session intervention with treatment as usual (exposure therapy for
trauma- and stressor-related disorder or anxiety disorder) combined with tACS.
Baseline, post-intervention assessments and follow-ups provide insight in
effects over time on physiological stress responses during anxiety- or
trauma-related stimulus exposure, PTSD and anxiety symptoms,
electrophysiological brain activity (EEG), and emotional working memory
performance.
Intervention
TACS is applied to the bilateral dorsolateral prefrontal cortex (DLPFC) at a
frequency of 5 Hz with an intensity of 2 mA (peak-to-peak) in the active tACS
group. In the control group (sham stimulation), the current is ramped up to 2
mA (30s) and immediately down (30s) again to 0 mA to mimic skin sensations
without an active stimulation period. TACS is applied right after an
exposure-based therapy session, for six consecutive exposure sessions in total.
Study burden and risks
The study involves a total of ten assessment time points for the participants,
with six of them taking place in their own treatment facility (intervention
sessions), two taking place in at the research center (baseline and
post-intervention) and two taking place online only (follow-ups). Participants
visit the research center for baseline and post-intervention assessments of
PTSD or anxiety disorder symptoms (clinical interview), electroencephalogram
(EEG) and working memory performance. Additionally, participants fill in online
self-report symptom questionnaires. At baseline only, participants are asked to
take saliva samples at home. Next, participants undergo the intervention (six
tACS + exposure sessions). Finally, there are online naturalistic follow-ups,
after the final tACS + exposure session that only includes the online
questionnaires.
The application of tACS as in this study is considered safe and not associated
with serious adverse events. Common adverse effects of tACS are minor (e.g.,
perceiving phosphenes, dizziness, headache, tingling, skin sensations)
Lundlaan 1
Utrecht 3584CX
NL
Lundlaan 1
Utrecht 3584CX
NL
Listed location countries
Age
Inclusion criteria
- Age: 18 years or older
- People with uniformed professions or post-active military veterans
- Treatment with protocolized exposure-based therapy sessions for anxiety
disorders or trauma- and stressor-related disorders (according to the
Diagnostic and Statistical Manual of Mental Disorders, or DSM-5, criteria),
e.g.
o Cognitive behavioural therapy with exposure, among which prolonged exposure
(PE)
o Narrative exposure therapy (NET)
o Eye Movement Desensitization and Reprocessing (EMDR) therapy
- Willingness and ability to understand the nature and content of the study, to
participate and to comply with the study requirements
- Willingness and ability to give written informed consent
- Provide written informed consent
Exclusion criteria
- Large metal or ferromagnetic objects in or around the head area, such as
electronic hearing devices, cochlear implants, deep brain stimulators, or metal
fragments near the skull (except for a dental wire).
- Opened skull or trepanation
- Pacemaker or neurostimulator
- Medication pump
- Epilepsy or family history of epilepsy
- Severe neurological condition or (a history of) brain damage
- Severe psychiatric condition comorbidity (e.g. schizophrenia, addiction)
- Skin damage or diseases around the intended tACS electrode sites (e.g.
psoriasis, eczema)
- Concurrent or recent (within previous month) neuromodulation /
neurostimulation (e.g., tDCS, TMS) treatment or study
- Pregnancy or possible pregnancy
Design
Recruitment
Medical products/devices used
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL84827.041.23 |