Gregory Brown

Publications (2)6.64 Total impact

• Article: Adolescents with major depression demonstrate increased amygdala activation.

  Tony T Yang, Alan N Simmons, Scott C Matthews, Susan F Tapert, Guido K Frank, Jeffrey E Max, Amanda Bischoff-Grethe, Amy E Lansing, Gregory Brown, Irina A Strigo, Jing Wu, Martin P Paulus
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  ABSTRACT: Functional neuroimaging studies have led to a significantly deeper understanding of the underlying neural correlates and the development of several mature models of depression in adults. In contrast, our current understanding of the underlying neural substrates of adolescent depression is very limited. Although numerous studies have consistently demonstrated a hyperactive amygdala in depressed adults, the few published pediatric studies have reported opposite results in the amygdala. Thus, the main purpose of this study was to further our knowledge of the underlying neural substrates of adolescent depression by examining the bilateral amygdala specifically and the whole brain in depressed adolescents compared to healthy controls. Twelve unmedicated adolescents diagnosed with current major depressive disorder without a comorbid psychiatric disorder and 12 well-matched controls ages 13 to 17 years performed a facial-emotion matching task during functional magnetic resonance imaging at 3 T. Region-of-interest analyses demonstrated: (1) significant bilateral amygdala activation in depressed and healthy adolescents, and (2) significantly greater left amygdala activation in depressed adolescents compared to controls. Whole-brain analysis revealed areas of significantly different brain activity in depressed adolescents compared to controls. These results suggest that (1) depressed adolescents without a comorbid psychiatric disorder exhibit an abnormally hyperactive amygdala compared to healthy controls; (2) models of adult depression might be extended to include depressed adolescents; and (3) neuropsychiatric interventions that have been developed in depressed adults should be further examined in adolescents.
  Journal of the American Academy of Child and Adolescent Psychiatry 01/2010; 49(1):42-51. · 4.98 Impact Factor
• Article: Depressed adolescents demonstrate greater subgenual anterior cingulate activity.

  Tony T Yang, Alan N Simmons, Scott C Matthews, Susan F Tapert, Guido K Frank, Amanda Bischoff-Grethe, Amy E Lansing, Jing Wu, Gregory G Brown, Martin P Paulus
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  ABSTRACT: Neuroimaging studies implicate the subgenual anterior cingulate cortex (sgACC) as a critical brain region in adult depression. However, unlike adult depression, little is known about the underlying neural substrates of adolescent depression, and there are no published data examining differences in sgACC activation between depressed and healthy adolescents. This study used functional magnetic resonance imaging to examine sgACC activity in 26 depressed and normal 13-17-year olds during the performance of a stop-signal task. Significantly greater sgACC activation was found in the depressed adolescents relative to controls. These results establish for the first time abnormal functioning of the sgACC in depressed adolescents and have important implications for understanding the underlying neural correlates and potential treatments of adolescent depression.
  Neuroreport 03/2009; 20(4):440-4. · 1.66 Impact Factor