Stress Disorder, Posttraumatic, Stress, Psychological
Conditions
Brief summary
The purpose of this study is to determine what is the neurological and cognitive impact of combat exposure and prolonged stress, in the form of service in the Israeli Defense Forces.
Detailed description
Attention biases in threat processing have been assigned a prominent role in the etiology and maintenance of anxiety disorders. This study aimed to characterize the mental resilience of combat soldiers, and explore the neuro-cognitive impact of prolonged stress, using eye-tracking, MRI and fMRI measurements. Participants will be assessed using questionnaires, cognitive tasks and magnetic imaging at 5 timepoints over the span of 4 years. Outcome measures will be depression, anxiety and post-traumatic scores, as well as dwell time on threat in eye-tracking paradigms tested in previous studies, and blood oxygen level-dependent (BOLD) signals in magnetic resonance imaging (MRI) measurements.
Interventions
OTHERCombat Exposure
Soldiers will be exposed to combat as part of their routine military service. The ROTC students will not be exposed to combat.
Sponsors
Medical Corps, Israel Defense Force
Tel Aviv University
Study design
Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
MALE
Age
18 Years to 23 Years
Healthy volunteers
No
Inclusion criteria
* Soldiers in the paratroopers brigade or students in Tel-Aviv University; * A signed consent form; * Hebrew native speakers.
Exclusion criteria
* A diagnosis of a neurological disorder (i.e., epilepsy, brain injury); * Drug or alcohol abuse; * Cannot undergo an MRI scan, due to metal implants or other metallic foreign bodies, claustrophobia, large tattoos or irremovable piercings; * Require glasses with a number greater than 7; * A diagnosis of psychotic or bipolar disorders.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Neurological measures - Gray matter volume | 4 years, from time point 1 to time point 5 | Gray matter volume, i.e. the density of brain cells in a particular region (outcome to be measured in cm3), to be derived from the MRI scans, and compared between the two groups across the various time points. |
| Change from baseline - PTSD Checklist for DSM-5 (PCL-5) score | 4 years, from time point 1 to time point 5 | PCL is questionnaire assessing posttraumatic stress disorder symptoms. It contains 20 items on a severity scale of 0-4, measuring the existence and severity of post-traumatic symptoms. The minimal score, indicating no post-traumatic stress, is 0. The maximal score is 80, indicating extremely severe post-traumatic stress. |
| Neurological measures - Functional connectivity | 4 years, from time point 1 to time point 5 | Functional connectivity, indicating the level of synchronous activity of certain brain regions during rest (temporal correlation is usually expressed as a Pearson's r); Also to be derived from the MRI scans, and compared between the two groups across the various time points. |
| Neurological measures - Structural connectivity | 4 years, from time point 1 to time point 5 | Structural connectivity between regions of the brain (Diffusivity is measured as 10-3mm2.s-1) and the properties of the white matter (expressed with Diffusion tensor imaging (DTI) measures, mainly Fractional Anisotropy (FA) and Mean Diffusivity (MD)); Also be derived from the MRI scans, and compared between the two groups across the various time points. |
| Neurological measures - Task activations | 4 years, from time point 1 to time point 5 | Task activations, and specifically the areas activated during the dot-probe task, and how they change over time (expressed as the level of the BOLD signal strength change during the task). To be derived from the MRI scans, and compared between the two groups across the various time points. |
Countries
Israel
Outcome results
None listed