Neural Substrates of Decision Making in Adults With Attention Deficit Hyperactivity Disorder

Abstract

The findings suggest that the neural circuits engaged during decision making differ in subjects with ADHD and healthy comparison subjects. This difference may explain observed deficits in motivated behaviors in ADHD. A better understanding of the nature of these deficits could ultimately be applied to refine treatment strategies for ADHD.

Cerebellar Vermis Involvement in Cocaine-Related Behaviors

“…However, in addiction disorders, in which the frontal lobes are known to be compromised (Goldstein and Volkow, 2002), cerebellar (and vermis) activity appears to increase to support several tasks involving frontal lobe function including monetary reward response (Martin-Soelch et al, 2001), response inhibition (Hester and Garavan, 2004), and working memory (Desmond et al, 2003). Vermis activation also occurs during reward tasks in Parkinson's and in attention deficit hyperactivity disorder patients, but not in comparison subjects (Ernst et al, 2003;Goerendt et al, 2004;Kunig et al, 2000). In addition, increased cerebellar (and vermis) activation occur to support working memory function in frontotemporal dementia, Parkinson's Disease, and schizophrenia, (Mentis et al, 2003;Meyer-Lindenberg et al, 2001;Rombouts et al, 2003).…”

“…However, as has been noted by Cotterill (2001), 'Muscular contraction is the nervous system's only externally directed product, and the signaling routes which pass through the various brain components must ultimately converge on the motor areas' (Cotterill, 2001). Indeed, recent data suggest that the cerebellum plays fundamental roles in a number of cognitive processes required for executing goal-directed and suppressing disadvantageous behaviors, including sensory functions (Paradiso et al, 1999), attention (Allen et al, 1997;Bischoff-Grethe et al, 2002), conditioned response learning (Logan and Grafton, 1995), and executive functions (Smith and Jonides, 1997;Ernst et al, 2003;Hülsmann et al, 2003) including response inhibition (Mostofsky et al, 2003). Thus, the cerebellum is critically interposed to link internal processing of exteroceptive and interoceptive stimuli to action.…”

Effects of methylphenidate on resting-state brain activity in normal adults: an fMRI study

“…In structural imaging, the volumes of the whole brain, prefrontal cortex, left caudate nucleus, and cerebellum are all reduced [1][2][3][4][5][6][7][8] . Functional neuroimaging studies of patients with ADHD show the involvement of multiple neuronal systems in this disorder, including the prefrontal cortex, parietal cortex, striatum and cerebellum [9][10][11][12][13][14][15] . These regions are organized in circuits.…”

Painel brasileiro de especialistas sobre diagnóstico do transtorno de déficit de atenção/hiperatividade (TDAH) em adultos

“…18 Preliminary researches with PET scan and magnetic nuclear resonance with spectroscopy, although such examinations are not indicated for the diagnosis of ADHD, indicate the presence of changes in frontal lobes, corpus callosum, basal ganglia and cerebellum. [19][20][21] There are two models that are most used in the understanding of the impairments associated with the ADHD. The first one emphasizes the role of the executive disorder secondarily to a deficient inhibitory control, as a result of changes in the dorsal frontal-striatal circuit and the dopaminergic mesocortical innervation.…”

“…19 There are scales to evaluate the symptoms referring back to childhood (Attention Deficit Hyperactivity Disorder Rating Scale -ADHD-RS) 40 and current symptoms (Conners' Adult Attention-Deficit Rating Scale -CAARS), 41 as well as semi-structured (Conners' Adult ADHD Diagnostic Interview for the DSM-IV -CAADID) 42 and structured interviews (Mini-International Neuropsychiatric Interview). 43 Some scales allow the investigation of the severity of the current symptoms based on the Wender-Utah diagnostic system (see below), such as the Wender-Reimherr Adult ADD Scale (WRAADS).…”