Biological psychiatry
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Biological psychiatry · Apr 2010
Randomized Controlled TrialEffects of the alpha4beta2 partial agonist varenicline on brain activity and working memory in abstinent smokers.
Cognitive alterations are a core symptom of nicotine withdrawal, contributing to smoking relapse. In rodents and humans, cognitive deficits can be reversed by treatment with the alpha4beta2 nicotinic receptor partial agonist varenicline. This neuroimaging study examined the neural mechanisms that underlie these effects. ⋯ This study provides novel evidence that the alpha4beta2 partial agonist varenicline increases working memory-related brain activity after 3 days of nicotine abstinence, particularly at high levels of task difficulty, with associated improvements in cognitive performance among highly dependent smokers.
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Biological psychiatry · Apr 2010
Randomized Controlled TrialIntranasal oxytocin improves emotion recognition for youth with autism spectrum disorders.
A diagnostic hallmark of autism spectrum disorders is a qualitative impairment in social communication and interaction. Deficits in the ability to recognize the emotions of others are believed to contribute to this. There is currently no effective treatment for these problems. ⋯ This study provides the first evidence that oxytocin nasal spray improves emotion recognition in young people diagnosed with autism spectrum disorders. Findings suggest the potential of earlier intervention and further evaluation of oxytocin nasal spray as a treatment to improve social communication and interaction in young people with autism spectrum disorders.
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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.