Anxiety disorders are present in as many as 13% of individuals in the United States and are the most prevalent subgroup of mental disorders. Anxiety disorders include conditions such as generalized anxiety disorder, post-traumatic stress disorder, obsessive-compulsive disorder, phobias and more.
Anxiety brain scans have shown us what the anxious brain actually looks like. In addition, the use of neuroimaging in anxiety disorders has revealed some interesting results that can lead to better treatment of anxiety disorders in the future.
Table of Contents
What Does the Anxious Brain Look Like?
Numerous neuroimaging studies have attempted to find out what anxiety looks like in the brain.
There is a strong link between anxiety and dysfunction of the brain’s frontal lobe. In one study that used CT scans, damage to several subregions of the frontal lobe was associated with anxiety. Another study using MRI technology showed that social anxiety disorder was linked to thinning grey matter in cortical regions. Grey matter changes have also been observed using MRI scanners in the prefrontal cortex of maltreated, anxious children.
As found during functional MRI scanning, the anxious brain also has a decreased connectivity network in key brain pathways — specifically, in a structure called the amygdala. An earlier study in patients with a generalized anxiety disorder had similar results. Specifically, the study found that the amygdala was communicating less with the cortex. Additionally, the amygdala also had more connections within itself.
Regions of the Brain Affected by Anxiety
The areas of the brain affected by anxiety the most include the prefrontal cortex, occipital cortex and temporal cortex. Additionally, the insula and anterior cingulate cortex have also been linked to anxiety. Regions of the limbic system (beneath the outer cortex) are also affected, which includes the amygdala and thalamus.
- Effects on Decision Making:
In neuroimaging research, the prefrontal cortex and anxiety appear to be especially linked. The prefrontal cortex is important for executive control, decision making, emotions and personality. Dysfunction in this brain area would explain why people with anxiety may have a hard time regulating their emotions.
- Effects on Fear & Behavior:
The amygdala and anxiety are also closely linked. The amygdala is largely known for its role in fear and anxiety-like behaviors in rodent studies of the brain and behavior. However, it’s not just rodents that use their amygdala during fearful and anxious behaviors — humans also use their amygdala in a similar way. Overactivity in this brain region is associated with more fear and more anxiety.
The anterior cingulate and insula are also a part of a “fear network” in the brain. They have been shown to be critical in the learning and extinguishing of fear responses. Fear responses are extinguished when fear-inducing stimuli create weaker responses over time due to repeated exposure.
Areas of the brain important for receiving, processing and interpreting sensory information have also been shown to be irregular in patients with anxiety. For example, the occipital cortex interprets visual sensory information while the temporal lobe processes auditory sensory information. Finally, the thalamus serves as a sensory relay station for the brain. This makes the most sense in post-traumatic stress disorder, which causes increased arousal and exaggerated startle responses to stimuli.
How Brain Scans Can Lead to Future Treatments for Anxiety Disorders
Brain scans may change the future treatment of anxiety disorders. Some scientists are trying to use brain scans to match patients with the therapy that will work best for them, since anxiety disorders can vary greatly from person to person. For example, one study of post-traumatic stress disorder patients showed that a smaller volume of the anterior cingulate cortex predicted a poor response to cognitive behavioral therapy.
In addition, neuroimaging allows for the opportunity to monitor the changes that occur from these therapies as well as the changes in a patient’s behavior. By doing so, the technology may ultimately help to refine and optimize therapeutic strategies.
Bystritsky, Alexander; et al. “Current diagnosis and treatment of anxiety disorders.” Pharmacy and Therapeutics, 2013. Accessed September 24, 2019.
Paradiso, Sergio; et al. “Frontal lobe syndrome reassessed: comparison of patients with lateral or medial frontal brain damage.” Journal of Neurology, Neurosurgery & Psychiatry, 1999. Accessed September 24, 2019.
Syal, Supriya; et al. “Grey matter abnormalities in social anxiety disorder: a pilot study.” Metabolic Brain Disease, 2012. Accessed September 24, 2019.
De Brito, Stéphane A..; et al. “Reduced orbitofrontal and temporal grey matter in a community sample of maltreated children.” Journal of child psychology and psychiatry, 2013. Accessed September 24, 2019.
Liao, Wei; et al. “Altered effective connectivity network of the amygdala in social anxiety disorder: a resting-state FMRI study.” PloS one, 2010. Accessed September 24, 2019.
Etkin, Amit; et al. “Disrupted amygdalar subregion functional connectivity and evidence of a compensatory network in generalized anxiety disorder.” Archives of general psychiatry, 2009. Accessed September 24, 2019.
Sehlmeyer, Christina; et al. “Human fear conditioning and extinction in neuroimaging: a systematic review.” PloS one, 2009. Accessed September 24, 2019.
Bryant, Richard A.; et al. “Rostral anterior cingulate volume predicts treatment response to cognitive-behavioural therapy for posttraumatic stress disorder.” Journal of psychiatry & neuroscience, 2008. Accessed September 24, 2019.
Holzschneider, Kathrin; Mulert, Christoph. “Neuroimaging in anxiety disorders.” Dialogues in clinical neuroscience, 2011. Accessed September 24, 2019.