Attention Deficit/Hyperactivity Disorder (ADHD) is characterized by symptoms of inattention, hyperactivity, and impulsivity. Deficits in inhibitory control and associated frontostriatal (FS) circuits have long been implicated in association with the disorder, but recent studies suggest that abnormal emotional processing within frontolimbic (FL) circuits may also be an important component of the hyperactivity evidenced in children with ADHD. Deficits in either domain may therefore be associated with ADHD and determine the clinical phenotype that a particular child exhibits. Using functional magnetic resonance imaging (fMRI), the current study aims to investigate simultaneously the functioning of FS and FL circuits in the same group of children as this is the best means to determine whether these two circuits have dissociable functions and neuropsychological correlates in children with ADHD. The study will examine in 60 children (ages 8 - 12) with (N=30) and without (N=30) ADHD the functioning of FS circuits during the performance of an inhibitory control fMRI task and the functioning of FL circuits during the performance of an emotion processing fMRI task. The hypotheses are that the functioning of these circuits will not only differ in children with and without ADHD but also that a double dissociation will be found in the behavioral correlates of FS and FL circuits. This application for a Mentored Patient-Oriented Research Career Development Award (K23) also requests funding for Jonathan Posner, MD to pursue training essential to becoming an independent investigator. This funding would support a comprehensive program including formal didactics and seminars from experts in the fields of pediatric neuroimaging, cognitive and affective neuroscience, and pediatric psychopathology. These training activities would enhance Dr. Posner's knowledge of a) fMRI techniques;b) the pathophysiology, phenomenology, and treatment of ADHD, c) affective and cognitive neuroscience;d) longitudinal neuroimaging study design;and e) the ethical conduct of scientific research.
ADHD is associated with a wide range of negative long-term outcomes, and causes significant hardship for children and families. Developing a better understanding of the neurobiology of ADHD may help advance research into the etiology, genetics, and treatment of the disorder.
|Posner, Jonathan; Siciliano, Francesco; Wang, Zhishun et al. (2014) A multimodal MRI study of the hippocampus in medication-naive children with ADHD: what connects ADHD and depression? Psychiatry Res 224:112-8|
|Posner, Jonathan (2014) A different approach to rising rates of ADHD diagnosis. J Am Acad Child Adolesc Psychiatry 53:697|
|Posner, Jonathan; Kass, Erica; Hulvershorn, Leslie (2014) Using stimulants to treat ADHD-related emotional lability. Curr Psychiatry Rep 16:478|
|Tseng, Angela; Bansal, Ravi; Liu, Jun et al. (2014) Using the circumplex model of affect to study valence and arousal ratings of emotional faces by children and adults with autism spectrum disorders. J Autism Dev Disord 44:1332-46|
|Posner, Jonathan; Park, Christine; Wang, Zhishun (2014) Connecting the dots: a review of resting connectivity MRI studies in attention-deficit/hyperactivity disorder. Neuropsychol Rev 24:3-15|
|Posner, Jonathan; Marsh, Rachel; Maia, Tiago V et al. (2013) Reduced functional connectivity within the limbic cortico-striato-thalamo-cortical loop in unmedicated adults with obsessive-compulsive disorder. Hum Brain Mapp :|
|Posner, Jonathan; Hellerstein, David J; Gat, Inbal et al. (2013) Antidepressants normalize the default mode network in patients with dysthymia. JAMA Psychiatry 70:373-82|
|Posner, Jonathan; Maia, Tiago V; Fair, Damien et al. (2011) The attenuation of dysfunctional emotional processing with stimulant medication: an fMRI study of adolescents with ADHD. Psychiatry Res 193:151-60|
|Posner, Jonathan; Nagel, Bonnie J; Maia, Tiago V et al. (2011) Abnormal amygdalar activation and connectivity in adolescents with attention-deficit/hyperactivity disorder. J Am Acad Child Adolesc Psychiatry 50:828-37.e3|