Clinical trial NCT03092609: Neuroplasticity in an Extended Amygdala Network as a Target Mechanism for Attention Bias Modification Outcome
Official title: Neuroplasticity in an Extended Amygdala Network as a Target Mechanism for Attention Bias Modification Outcome
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Anxiety
Keywords: Attentional Bias to Threat
Lead sponsor: Northern Michigan University
Sponsor class: OTHER
Collaborators: name: National Institute of Mental Health (NIMH)
First posted: 2017-03-28
Enrollment: 119
Sex: ALL
Minimum age (years): 18
Maximum age (years): 37
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Anxiety disorders are one of the most common psychological disorders. Underlying anxiety is an increased attentional bias to threat, which has been identified as a causal contributor in the development of anxiety. Given this causal relationship, attention bias modification was introduced as a treatment option where anxiety is reduced by training individuals to direct their attention away from threat and thereby decreasing anxiety. Over a decade of research using this approach, called attention bias modification (ABM), suggests that overall the approach is effective in reducing anxiety. Although ABM appears to be a very promising treatment option for anxiety, there are several factors limiting the effectiveness of ABM. These include the recognition of individual-level needs and a known underlying mechanism of action by which ABM is effective. Neuroimaging evidence suggests that attentional bias to visual threat is associated with a network of brain regions including the amygdala, anterior cingulate cortex, and visual cortex. In human participants, experience-dependent neuroplasticity is visible in voxel-based morphometry based measures of gray matter volume following training. Recently, voxel-based morphometry measures of gray matter volume have been linked to dendritic spine density-a known cellular mechanism for learning-related neuroplasticity. Thus, voxel-based morphometry measures are ideally suited to measure learning-related neuroplasticity following attention bias modification. In this proposal participants' level of attentional bias, anxiety, and gray matter volume will be measured before and after completing six weeks of attention bias modification training (N = 50) or attention control training (N= 50). The proposal aims to (1) establish that pre-treatment bias predicts variability in gray matter volume in the extended amygdala and anterior cingulate cortex, (2) assess the extent to which reduced extended amygdala and anterior cingulate cortex gray matter volume following ABM underlies reductions in attentional bias and anxiety, and (3) Establish pre-treatment bias as a predictor of successful ABM as measured by reduced bias, reduced anxiety, and reduced gray matter volume in the extended amygdala and anterior cingulate cortex. Consistent with the objectives of the AREA grant and NIMH's focus on identifying and validating new targets for treatment development that underlie disease mechanisms, the current proposal plans to involve students at a rural primarily undergraduate university in a research project aimed at establishing neuroplasticity in the extended amygdala and anterior cingulate cortex as a target mechanism for ABM training outcome, which could be used to objectively track training-related outcomes in anxiety treatment.


Eligibility criteria: Inclusion Criteria:

* Handedness (right handed)
* Normal Vision
* High Anxiety
* Preexisting Attentional Bias

Exclusion Criteria:

* No MRI contraindications
* No History of Head Injury
* No Neurological History
* Psychological History
* Limited Recreational Drug Use, No Abuse
* Limited Prescription Drug Use, No Abuse
* No Claustrophobia
* Not Pregnant

Primary outcomes:
measure: Attentional Bias
timeFrame: Baseline and after 6 weeks of the intervention
Secondary outcomes:
measure: State and Trait Anxiety
timeFrame: Baseline and after 6 weeks of the intervention
Other outcomes:
measure: MRI measures of gray matter volume
timeFrame: Baseline and after 6 weeks of the intervention
measure: MRI measures of structural and functional connectivity
timeFrame: Baseline and after 6 weeks of the intervention
Locations:
city: Marquette
country: United States
facility: Northern Michigan University
state: Michigan
Study officials:
affiliation: Northern Michigan University
name: Joshua M Carlson, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Carlson JM, Fang L, Koster EHW, Andrzejewski JA, Gilbertson H, Elwell KA, Zuidema TR. Neuroplastic changes in anterior cingulate cortex gray matter volume and functional connectivity following attention bias modification in high trait anxious individuals. Biol Psychol. 2022 Jul;172:108353. doi: 10.1016/j.biopsycho.2022.108353. Epub 2022 May 13.
citation: Carlson JM, Fang L. Attentional bias to threat and gray matter volume morphology in high anxious individuals. Cogn Affect Behav Neurosci. 2022 Jun;22(3):600-609. doi: 10.3758/s13415-021-00968-9. Epub 2021 Nov 9.