Attention-deficit/hyperactivity disorder (ADHD) is hypothesized to be due, in part, to structural defects in brain networks influencing cognitive, affective, and motor behaviors. Although the current literature on fiber tracts is limited in ADHD, gray matter abnormalities suggest that white matter (WM) connections may be altered selectively in neural systems. A prior study (Ashtari et al. 2005), using diffusion tensor magnetic resonance imaging (DT-MRI), showed alterations within the frontal and cerebellar WM in children and adolescents with ADHD. In this study of adults with childhood ADHD, we hypothesized that fiber pathways subserving attention and executive functions (EFs) would be altered. To this end, the cingulum bundle (CB) and superior longitudinal fascicle II (SLF II) were investigated in vivo in 12 adults with childhood ADHD and 17 demographically comparable unaffected controls using DT-MRI. Relative to controls, the fractional anisotropy (FA) values were significantly smaller in both regions of interest in the right hemisphere, in contrast to a control region (the fornix), indicating an alteration of anatomical connections within the attention and EF cerebral systems in adults with childhood ADHD. The demonstration of FA abnormalities in the CB and SLF II in adults with childhood ADHD provides further support for persistent structural abnormalities into adulthood.
Background Gray and white matter volume deficits have been reported in many structural magnetic resonance imaging (MRI) studies of children with attention-deficit/hyperactivity disorder (ADHD); however, there is a paucity of structural MRI studies of adults with ADHD. This study used voxel based morphometry and applied an a priori region of interest approach based on our previous work, as well as from well-developed neuroanatomical theories of ADHD. Methods Seventy-four adults with DSM-IV ADHD and 54 healthy control subjects comparable on age, sex, race, handedness, IQ, reading achievement, frequency of learning disabilities, and whole brain volume had an MRI on a 1.5T Siemens scanner. A priori region of interest hypotheses focused on reduced volumes in ADHD in dorsolateral prefrontal cortex, anterior cingulate cortex, caudate, putamen, inferior parietal lobule, and cerebellum. Analyses were carried out by FSL-VBM 1.1. Results Relative to control subjects, ADHD adults had significantly smaller gray matter volumes in parts of six of these regions at p ≤ .01, whereas parts of the dorsolateral prefrontal cortex and inferior parietal lobule were significantly larger in ADHD at this threshold. However, a number of other regions were smaller and larger in ADHD (especially fronto-orbital cortex) at this threshold. Only the caudate remained significantly smaller at the family-wise error rate. Conclusions Adults with ADHD have subtle volume reductions in the caudate and possibly other brain regions involved in attention and executive control supporting frontostriatal models of ADHD. Modest group brain volume differences are discussed in the context of the nature of the samples studied and voxel based morphometry methodology.
Objective Although attention-deficit/hyperactivity disorder (ADHD) in adults is associated with significant morbidity and dysfunction and afflicts both sexes, relatively few imaging studies have examined females and none have had sufficient power to adequately examine sex differences. We sought to examine sex differences in neural functioning of ADHD adults during performance on a verbal working memory task. Method Participants were 44 adults with ADHD matched on age, sex, and estimated IQ to 49 controls. Accuracy and reaction time on an n-back task were measures of working memory performance. The blood-oxygenation-level dependent functional magnetic resonance imaging response was used as a measure of neural activity. Results A group by sex ANOVA showed no between-group differences in either reaction time or percent correct for the working memory task. For imaging data, with both sexes combined, ADHD adults showed less activity than controls in prefrontal regions. However, sex-by-group analyses revealed an interaction, such that male ADHD adults showed significantly less activity lateralized to right frontal, temporal and subcortical regions, as well as left occipital and cerebellar regions relative to male controls, whereas female ADHD adults showed no differences from female controls. Exploratory correlation analyses revealed negative associations between working memory related activation and number of hyperactive symptoms for males and number of inattentive symptoms for females. Conclusions Male but not female adults with ADHD showed significantly altered patterns of neural activity during performance on a verbal working memory task. Males and females showed different associations between neural activity and ADHD symptoms.
Results support calls to cease use of the terms "addict", "alcoholic", "opioid addict", and "substance abuser". Additionally, it is suggested that "recurrence of use" and "pharmacotherapy" be used for their overall positive benefits. Both "medication-assisted recovery" and "long-term recovery" are positive terms and can be used when applicable without promoting stigma.
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