The ABCD study is a new and ongoing project of very substantial size and scale involving 21 data acquisition sites. It aims to recruit 11,500 children and follow them for ten years with extensive assessments at multiple timepoints. To deliver on its potential to adequately describe adolescent development, it is essential that it adopt recruitment procedures that are efficient and effective and will yield a sample that reflects the nation's diversity in an epidemiologically informed manner. Here, we describe the sampling plans and recruitment procedures of this study. Participants are largely recruited through the school systems with school selection informed by gender, race and ethnicity, socioeconomic status, and urbanicity. Procedures for school selection designed to mitigate selection biases, dynamic monitoring of the accumulating sample to correct deviations from recruitment targets, and a description of the recruitment procedures designed to foster a collaborative attitude between the researchers, the schools and the local communities, are provided.

We recruited 14 unmedicated patients with Kraepelinian schizophrenia (12 men and 2 women; mean age = 47 years old), 27 non-Kraepelinian patients (21 men and 6 women; mean age = 36.4 years old) and a group of 56 age- and sex-matched healthy volunteers. FDG positron emission tomography and MRI scans were coregistered for both voxel-by-voxel statistical mapping and stereotaxic regions of interest analysis. While both Kraepelinian and non-Kraepelinian patients showed equally lower uptake than healthy volunteers in the frontal lobe, the temporal lobes (Brodmann areas 20 and 21) showed significantly greater decreases in Kraepelinian than in non-Kraepelinian patients. Kraepelinian patients had lower FDG uptake in parietal regions 39 and 40, especially in the right hemisphere, while non-Kraepelinian patients had similar reductions in the left. Only non-Kraepelinian patients had lower caudate FDG uptake than healthy volunteers. While both patient groups had lower uptake than healthy volunteers in the medial dorsal nucleus of the thalamus, Kraepelinian patients alone had higher uptake in the ventral nuclei of the thalamus. Kraepelinian patients also showed higher metabolic rates in white matter. Our results are consistent with other studies indicating that Kraepelinian schizophrenia is a subgroup of schizophrenia, characterized by temporal and right parietal deficits and normal rather than reduced caudate uptake. It suggests that Kraepelinian schizophrenia may be more primarily characterized by FDG uptake decreased in both the frontal and temporal lobes, while non-Kraepelinian schizophrenia may have deficits more limited to the frontal lobe. This is consistent with some neuropsychological and prognosis reports of disordered sensory information processing in Kraepelinian schizophrenia in addition to deficits in frontal lobe executive functions shared with the non-Kraepelinian subtype.

Objective Physiological and pharmacological studies indicate that altered brain serotonin (5-HT) activity could contribute to a susceptibility to develop appetitive and behavioural alterations that are characteristic of bulimia nervosa (BN). Methods Eight individuals recovered from BN (REC BN) and eight healthy control women were scanned with [11C]DASB and positron emission tomography imaging of the 5-HT transporter (5-HTT). Logan graphical analysis was applied and parametric binding potential (BPnon displaceable (ND)) images were generated. Voxel-by-voxel t-tests and a region of interest (ROI) analysis were conducted. Results REC BN had significantly lower [11C]DASB BPND in midbrain, superior and inferior cingulate and significantly higher [11C]DASB BPND in anterior cingulate and superior temporal gyrus in the voxel based analysis. ROI analysis indicated lower [11C]DASB BPND in midbrain (p=.07), containing the dorsal raphe, in REC BN, consistent with our earlier studies. Discussion These preliminary findings of a small scale study confirm and extend previous data suggesting that ill and recovered BN have altered 5-HTT measures, which potentially contribute to BN symptomology and/or differential responses to medication.

individuals at clinical high risk (CHR) for developing schizophrenia is not well characterized. Methods: We studied youth (ages 11-30) meeting CHR for psychosis criteria (n = 30), individuals early in their schizophrenia illness (ESZ; n = 22), and healthy adolescents and young adults (HC; n = 72). Functional magnetic resonance imaging was collected during Go/NoGo response inhibition task performance. Voxelwise main effects of Group (p<.001 height threshold, family-wise error corrected P < .05) for incorrect NoGo versus correct Go activations were examined, and correlated with the signal detection measure d'. Results: Error rates and error-related activations in anterior cingulate and dorsolateral prefrontal cortex were equivalent across the three groups. A significant main effect of Group for the contrast of NoGo errors relative to correct Go responses was detected in the left cerebellum. This main effect of Group was explained by the ESZ group showing significantly less errorrelated activation, relative to the HC group (with the CHR group differing from neither). In HC individuals, higher error-related contrast values in this cerebellar region significantly related to better d', a relationship that was not present in either of the clinical groups (group slopes difference, P < .05). Conclusion: ESZ patients showed significantly less cerebellar activation during error processing, relative to HC participants. In HCs, cerebellar activation in this region was significantly related to better signal detection. A role for the cerebellum in performance monitoring is increasingly recognized, and these data suggest that the normal relationship between cerebellar error-related responses and task performance breaks down in both CHR and ESZ groups. Background: Schizophrenia has been associated with thalamic hyperconnectivity with sensory regions, including the middle and superior temporal gyrus, and hypoconnectivity with cerebellar and prefrontal regions. While thalamic dysconnectivity has been consistently replicated in chronic schizophrenia samples, less is known about when these abnormalities emerge in the illness course and if they are present prior to illness onset. Methods: Resting-state fMRI data were collected from clinical high-risk youth (n = 45; CHR), early illness schizophrenia (n = 74; ESZ) patients, and healthy controls (n = 85; HC). Age-adjusted whole-brain functional connectivity, seeded from the thalamus, was compared among the three groups. Main effects of group (FDR-corrected, p = .01) were followed up with Tukey-corrected pairwise comparisons. Results: Significant main effects of group were observed in 8 regions: 2 left middle temporal regions, 2 right middle temporal regions, a left superior temporal region, a right superior temporal region, a left cerebellar region, and a bilateral thalamic region. Pairwise follow-up tests (P < .05) conducted on extracted mean connectivity values revealed that, consistent with data comparing chronic schizophrenia patients to HCs, ESZ patients demonstrated greater thalam...

individuals at clinical high risk (CHR) for developing schizophrenia is not well characterized. Methods: We studied youth (ages 11-30) meeting CHR for psychosis criteria (n = 30), individuals early in their schizophrenia illness (ESZ; n = 22), and healthy adolescents and young adults (HC; n = 72). Functional magnetic resonance imaging was collected during Go/NoGo response inhibition task performance. Voxelwise main effects of Group (p<.001 height threshold, family-wise error corrected P < .05) for incorrect NoGo versus correct Go activations were examined, and correlated with the signal detection measure d'. Results: Error rates and error-related activations in anterior cingulate and dorsolateral prefrontal cortex were equivalent across the three groups. A significant main effect of Group for the contrast of NoGo errors relative to correct Go responses was detected in the left cerebellum. This main effect of Group was explained by the ESZ group showing significantly less errorrelated activation, relative to the HC group (with the CHR group differing from neither). In HC individuals, higher error-related contrast values in this cerebellar region significantly related to better d', a relationship that was not present in either of the clinical groups (group slopes difference, P < .05). Conclusion: ESZ patients showed significantly less cerebellar activation during error processing, relative to HC participants. In HCs, cerebellar activation in this region was significantly related to better signal detection. A role for the cerebellum in performance monitoring is increasingly recognized, and these data suggest that the normal relationship between cerebellar error-related responses and task performance breaks down in both CHR and ESZ groups. Background: Schizophrenia has been associated with thalamic hyperconnectivity with sensory regions, including the middle and superior temporal gyrus, and hypoconnectivity with cerebellar and prefrontal regions. While thalamic dysconnectivity has been consistently replicated in chronic schizophrenia samples, less is known about when these abnormalities emerge in the illness course and if they are present prior to illness onset. Methods: Resting-state fMRI data were collected from clinical high-risk youth (n = 45; CHR), early illness schizophrenia (n = 74; ESZ) patients, and healthy controls (n = 85; HC). Age-adjusted whole-brain functional connectivity, seeded from the thalamus, was compared among the three groups. Main effects of group (FDR-corrected, p = .01) were followed up with Tukey-corrected pairwise comparisons. Results: Significant main effects of group were observed in 8 regions: 2 left middle temporal regions, 2 right middle temporal regions, a left superior temporal region, a right superior temporal region, a left cerebellar region, and a bilateral thalamic region. Pairwise follow-up tests (P < .05) conducted on extracted mean connectivity values revealed that, consistent with data comparing chronic schizophrenia patients to HCs, ESZ patients demonstrated greater thalam...