Although attention-deficit/hyperactivity disorder (ADHD) is associated both with brain alterations in attention and executive function (EF) circuitry and with genetic variations within the dopamine system (including the dopamine transporter gene [SLC6A3]), few studies have directly investigated how genetic variations are linked to brain alterations. We sought to examine how a polymorphism in the 3' untranslated region (UTR) of SLC6A3, associated with ADHD in meta-analysis, might contribute to variation in dorsal anterior cingulate cortex (dACC) function in subjects with ADHD.
BACKGROUND: This is a unique hypothalamic magnetic resonance imaging (MRI) study in schizophrenia, an important region in the limbic system. We hypothesized abnormal volumetric increases, with greater severity in multiplex families (more than one ill member) compared with simplex families (one ill). We tested the hypothesis that normal hypothalamic sexual dimorphism is disrupted in schizophrenia.
BACKGROUND: Schizophrenia is characterized by subcortical and cortical brain abnormalities. Evidence indicates that some nonpsychotic relatives of schizophrenic patients manifest biobehavioral abnormalities, including brain abnormalities. The goal of this study was to determine whether amygdala-hippocampal and thalamic abnormalities are present in relatives of schizophrenic patients.
The amygdala is instrumental to a set of brain processes that lead to cocaine consumption, including those that mediate reward and drug craving. This study examined the volumes of the amygdala and hippocampus in cocaine-addicted subjects and matched healthy controls and determined that the amygdala but not the hippocampus was significantly reduced in volume. The right-left amygdala asymmetry in control subjects was absent in the cocaine addicts.
OBJECTIVE: We sought to examine preliminary results of brain alterations in anterior cingulate cortex (ACC) in treatment-naïve adults with ADHD. The ACC is a central brain node for the integration of cognitive control and allocation of attention, affect and drive. Thus its anatomical alteration may give rise to impulsivity, hyperactivity and inattention, which are cardinal behavioral manifestations of ADHD.
METHOD: Segmentation and parcellation of the ACC was performed on controls (n = 22), treated (n = 13) and treatment-naïve adults with ADHD (n = 13).
Magnetic resonance imaging (MRI) has revolutionized the practical demands of clinical neurology. This technology promises now to advance neurology in theoretical and applied realms of fundamental human brain science. We emphasize here two domains in which these advances will occur. The first is volumetric morphometry of the human brain. With MRI the multiple levels of processing of the brain may be characterized in terms of their absolute volumes and their relative sizes, perspectives indispensable for our understanding of the development and operation of neural systems.
BACKGROUND: Regional prefrontal cortex gray matter reductions have been identified in schizophrenia, likely reflecting a combination of genetic vulnerability and disease effects. Few morphometric studies to date have examined regional prefrontal abnormalities in non-psychotic biological relatives who have not passed through the age range of peak risk for onset of psychosis. We conducted a region-of-interest morphometric study of prefrontal subregions in adolescent and young adult relatives of schizophrenia patients.
BACKGROUND: Relatively few magnetic resonance imaging studies of schizophrenia have investigated the entire cerebral cortex. Most focus on only a few areas within a lobe or an entire lobe. To assess expected regional alterations in cortical volumes, we used a new method to segment the entire neocortex into 48 topographically defined brain regions. We hypothesized, based on previous empirical and theoretical work, that dorsolateral prefrontal and paralimbic cortices would be significantly volumetrically reduced in patients with schizophrenia compared with normal controls.
INTRODUCTION: A significant number of children with bipolar disorder (BP) have co-morbid attention-deficit/hyperactivity disorder (ADHD). It is unknown if these children have neuroimaging findings unique to their co-morbid presentation, or if their brain findings are similar to children diagnosed with BP alone.
