Anxiety Disorders are one of the most common psychiatric conditions. It is estimated that between 10 and 20 percent of the American people aged 18 and older suffer from some sort of Anxiety Disorder. That’s 30 to 60 million people!
The Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) of the American Psychiatric Association classifies nearly a dozen different Anxiety Disorders, from Acute Stress Disorder to Obsessive-Compulsive Disorder to Panic Attack to Post-Traumatic Stress Disorder.
New research from the University of Illinois groups these dozen disorders into two different types based on brain activities:
- Anxious apprehension (verbal rumination and worry)
- Anxious arousal (intense fear, panic, or both)
These two kinds of Anxiety may occur alone or in combination, with potentially important implications for treatment. Previous studies and treatment have not always differentiated between these two types.
Study calls for careful evaluation before treatment
University of Illinois psychology professor Gregory A. Miller, co-principal investigator in the research said:
Whether you want to treat anxiety psychologically or biologically – and we know that either type of intervention affects both the psychology and the biology of the person – [our] findings are a reminder that you might want to assess people carefully before you embark on a particular type of treatment.
He further states that this study “… is biological validation of the proposal of the psychological differentiation of types of anxiety.” The study by University of Illinois researchers appeared in the May, 2007 issue of Psychophysiology.
How the research was conducted
The researchers, Dr. Miller and Wendy Heller, used functional Magnetic Resonance Imaging (fMRI) to map the brain areas with increased neural activity during a variety of psychological probes. They selected 42 subjects from a pool of 1,099 people using psychological tests to separate them into groups with “high anxious apprehension” and “high anxious arousal.” These subjects were further selected as having no mood disorders or other complicating factors.
Miller and Heller found that the anxious apprehension group showed increased activity in the left brain region associated with speech production.
The anxious arousal group had more activity in a region of the right brain believed to be involved in tracking and responding to information signaling danger.
Other studies using electroencephalographic (EEG) methods had found that patients diagnosed with Generalized Anxiety Disorder and Obsessive-Compulsive Disorder had heightened activity in the left brain. Patients with Panic Disorder, panic symptoms or those subjected to high stress situations exhibited enhanced activity in the right brain.
The University of Illinois study is the first to localize the affected regions within each brain hemisphere that seem to matter to the different kinds of Anxiety Disorder. In addition, a related and important finding was to distinguish the left-brain region involved in anxious apprehension from a nearby structure that is associated with positive emotional processing.
The implications of the study
It is interesting that the apprehension group, characterized by Miller and Heller as having “high anxious apprehension” with a tendency toward verbal rumination and worry, should be associated in the brain with the speech centers. These are among the symptoms of a number of Anxiety Disorders, such as Generalized Anxiety Disorder.
It is even more interesting that the “high anxious arousal” group, characterized by intense fear, panic, or both, should have activity in the part of the brain associated with signaling danger. This is a symptom of mental disorders such as panic attacks, which can lead to Panic Disorder.
This study is further proof that Anxiety Disorder has a definite basis in the brain, and is not entirely a product of environmental factors or a person’s character. Unfortunately, our society and too many people with Anxiety feel that they are personally to blame for their problems, that it is just a “character flaw.” The stigma that accompanies Anxiety and other mental disorders leads to untold suffering each and every day.
What do you think?
It is intriguing to think that this finding might lead to an entirely new classification system for Anxiety Disorders, and with that, new modes of treatment.
- Do you think that Anxiety Disorders can be classified under just two headings?
- What do you think of the implications of this study?
As always, your comments are welcome!
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Sources used in this post:
University of Illinois press release: Brain activity reflects differences in types of anxiety
Psych Central article: Brain Response to Anxiety
Last update: January 1, 2009