Biological psychiatry
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Biological psychiatry · Apr 2010
Attentional control activation relates to working memory in attention-deficit/hyperactivity disorder.
Attentional control difficulties in individuals with attention-deficit/hyperactivity disorder (ADHD) might reflect poor working memory (WM) ability, especially because WM ability and attentional control rely on similar brain regions. The current study examined whether WM ability might explain group differences in brain activation between adults with ADHD and normal control subjects during attentional demand. ⋯ The inability to maintain an appropriate task set in young adults with combined type ADHD, associated with decreased activity in left DLPFC, might in part be due to poor WM ability. Furthermore, in individuals with ADHD, higher WM ability might relate to increased recruitment of stimulus-driven attention and response selection processes, perhaps as a compensatory strategy.
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Biological psychiatry · Apr 2010
Functional disconnection of frontal cortex and visual cortex in attention-deficit/hyperactivity disorder.
Current pathophysiologic models of attention-deficit/hyperactivity disorder (ADHD) suggest that impaired functional connectivity within brain attention networks may contribute to the disorder. In this electroencephalographic (EEG) study, we analyzed cross-frequency amplitude correlations to investigate differences in cue-induced functional connectivity in typically developing children and children with ADHD. ⋯ Our findings provide neurophysiological evidence for a specific deficit in top-down attentional control in children with ADHD that is manifested as a functional disconnection between frontal and occipital cortex.
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Biological psychiatry · Mar 2010
Randomized Controlled Trial Clinical TrialDeep brain stimulation for intractable obsessive compulsive disorder: pilot study using a blinded, staggered-onset design.
Prior promising results have been reported with deep brain stimulation (DBS) of the anterior limb of the internal capsule in cases with severe obsessive compulsive disorder (OCD) who had exhausted conventional therapies. ⋯ This pilot study suggests that DBS of the ventral capsule/ventral striatum region is a promising therapy of last resort for carefully selected cases of severe and intractable OCD. Future research should attend to subject selection, lead location, DBS programming, and mechanisms underpinning therapeutic benefits.