#CAN13 Can a brain scan predict your vulnerability to anxiety disorders?
This is part of a blog post series for the 2013 Canadian Association for Neuroscience annual conference.
Poster: Increased Activity of Frontal and Limbic Regions to Emotional Stimuli in Children At-Risk for Anxiety Disorders. R Christensen, University of Toronto. Image: nottingham.ac.uk
TL;DR: no.However, a new study reports that functional changes do occur in the brain long before anxiety disorders first strike.
Genetic studies tell us having one parent with anxiety disorder significantly increases a child’s chance of getting the same disorder. Because of this genetic basis, researchers believe that early changes in a high-risk child’s brain may precede full-blown disorder.
To test this hypothesis, they recruited 25 high-risk and 20 low-risk kids. To meet “high-risk” criteria, the kids must have at least one parent diagnosed with anxiety disorder. Low-risk kids are those with parents with no psychiatric illness. Researchers then put the kids into an fMRI machine, and showed them a computer-generated face with different expressions. Some were neutral (think passport photos), while others were either happy or angry.
Both groups of children responded to neutral faces similarly. However, when high-risk kids looked at emotionally rich faces (both angry and happy), their brain activity skyrocketed to way beyond that of low-risk kids. The limbic and frontal regions were especially hyperactive. We know that the limbic system is involved in emotion processing, while the frontal system modulates anxiety.
Surprisingly, at the time of study, only 4 kids were diagnosed with some sort of anxiety disorder. However, 76% eventually developed anxiety-related disorders, such as social phobia, panic attacks and agrophobia.
These results show that fMRI has some predictive power, but that doesn’t mean that it’s ready to hit the psychiatry stage as a diagnostic tool. The correlation between enhanced frontal/limbic processing and anxiety disorder risk only appeared on AVERAGE. That is, we see the link only when looking at the population level. Ours brains are unique little flowers: each person, regardless of risk for anxiety, will show a different pattern of activation. At the moment, the gold standard is still the psychiatry bible, DSM-V.
However, this doesn’t mean we shouldn’t try to get there. As the director of the National Institute of Mental Health said “It is increasingly evident that mental illness will be best understood as disorders of brain structure and function that implicate specific domains of cognition, emotion, and behavior.”
Note: This is the last post on CAN. Overall it's been very fun! I HIGHLY recommend checking out the work of Helen Meyburg on Deep Brain Stimulation as a treatment for depression (Youtube), and Shayna Rosembaum's work on amnesia.