CHAMPAIGN, Ill. A new study of brain activity in depressed and anxious people indicates that some of the ill effects of depression are modified for better or for worse by anxiety.
The study, in the journal Cognitive, Affective & Behavioral Neuroscience, looked at depression and two types of anxiety: anxious arousal, the fearful vigilance that sometimes turns into panic; and anxious apprehension, better known as worry.
The researchers used functional Magnetic Resonance Imaging (fMRI) at the Beckman Institute's Biomedical Imaging Center to look at brain activity in subjects who were depressed and not anxious, anxious but not depressed, or who exhibited varying degrees of depression and one or both types of anxiety.
"Although we think of depression and anxiety as separate things, they often co-occur," said University of Illinois psychology professor Gregory A. Miller, who led the research with Illinois psychology professor Wendy Heller. "In a national study of the prevalence of psychiatric disorders, three-quarters of those diagnosed with major depression had at least one other diagnosis. In many cases, those with depression also had anxiety, and vice versa."
Previous studies have generally focused on people who were depressed or anxious, Miller said. Or they looked at both depression and anxiety, but lumped all types of anxiety together.
Miller and Heller have long argued that the anxiety of chronic worriers is distinct from the panic or fearful vigilance that characterizes anxious arousal.
In an earlier fMRI study, they found that the two types of anxiety produce very different patterns of activity in the brain. Anxious arousal lights up a region of the right inferior temporal lobe (just behind the ear). Worry, on the other hand, activates a region in the left frontal lobe that is linked to speech production.
(Other research has found that depression, by itself, activates a region
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University of Illinois at Urbana-Champaign