Larry J Seidman

We examined the status of the neural network mediating the default mode of brain function, which typically exhibits greater activation during rest than during task, in patients in the early phase of schizophrenia and in young first-degree relatives of persons with schizophrenia. During functional MRI, patients, relatives, and controls alternated between rest and performance of working memory (WM) tasks. As expected, controls exhibited task-related suppression of activation in the default ...

BACKGROUND: Neuroimaging studies have shown structural alterations in several brain regions in children and adults with attention deficit hyperactivity disorder (ADHD). Through the formation of the international ENIGMA ADHD Working Group, we aimed to address weaknesses of previous imaging studies and meta-analyses, namely inadequate sample size and methodological heterogeneity. We aimed to investigate whether there are structural differences in children and adults with ADHD compared with ...

IMPORTANCE: Severe neuropsychiatric conditions, such as schizophrenia, affect distributed neural computations. One candidate system profoundly altered in chronic schizophrenia involves the thalamocortical networks. It is widely acknowledged that schizophrenia is a neurodevelopmental disorder that likely affects the brain before onset of clinical symptoms. However, no investigation has tested whether thalamocortical connectivity is altered in individuals at risk for psychosis or whether ...

Importance: Children at familial high risk of schizophrenia spectrum disorders (FHR-SZ) or bipolar disorder (FHR-BP) exhibit neurocognitive impairments. Large studies of neurocognition in young children at familial high risk at the same age are important to differentiate the pathophysiology and developmental trajectory of these 2 groups.

Objective: To characterize neurocognitive functions in 7-year-old children with FHR-SZ or FHR-BP and a control population.

Design, Setting, and ...

OBJECTIVES: Impaired social, role, and neurocognitive functioning are preillness characteristics of people who later develop psychosis. In people with schizophrenia, neurocognition and negative symptoms are associated with functional impairment. We examined the relative contributions of neurocognition and symptoms to social and role functioning over time in clinically high-risk (CHR) individuals and determined if negative symptoms mediated the influence of cognition on ...

OBJECTIVE: The association between deficits in executive functioning and functional outcomes was examined among adults with attention deficit hyperactivity disorder (ADHD).

METHOD: Subjects were adults who did (N=213) and did not (N=145) meet DSM-IV criteria for ADHD. The authors defined having deficits in executive functioning as having at least two measures of executive functioning with scores 1.5 standard deviations below those of matched comparison subjects.

RESULTS: Significantly ...

OBJECTIVE: The effect of antipsychotic medication on neurocognitive function remains controversial, especially since most previous work has compared the effects of novel antipsychotic medications with those of high doses of conventional medications. This study compares the neurocognitive effects of olanzapine and low doses of haloperidol in patients with first-episode psychosis.

METHOD: Patients with a first episode of schizophrenia, schizoaffective disorder, or schizophreniform disorder ...

Social cognition, the mental operations that underlie social interactions, is a major construct to investigate in schizophrenia. Impairments in social cognition are present before the onset of psychosis, and even in unaffected first-degree relatives, suggesting that social cognition may be a trait marker of the illness. In a large cohort of individuals at clinical high risk for psychosis (CHR) and healthy controls, three domains of social cognition (theory of mind, facial emotion ...

Importance: Neurophysiologic measures of early auditory information processing (EAP) are used as endophenotypes in genomic studies and biomarkers in clinical intervention studies. Research in schizophrenia has established correlations among measures of EAP, cognition, clinical symptoms, and functional outcome. Clarifying these associations by determining the pathways through which deficits in EAP affect functioning would suggest when and where to therapeutically intervene.

Objectives: To ...

Importance: Neurocognition is a central characteristic of schizophrenia and other psychotic disorders. Identifying the pattern and severity of neurocognitive functioning during the "near-psychotic," clinical high-risk (CHR) state of psychosis is necessary to develop accurate risk factors for psychosis and more effective and potentially preventive treatments.

Objectives: To identify core neurocognitive dysfunctions associated with the CHR phase, measure the ability of neurocognitive tests ...

OBJECTIVE: The lack of an accepted standard for measuring cognitive change in schizophrenia has been a major obstacle to regulatory approval of cognition-enhancing treatments. A primary mandate of the National Institute of Mental Health's Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) initiative was to develop a consensus cognitive battery for clinical trials of cognition-enhancing treatments for schizophrenia through a broadly based scientific ...

BACKGROUND: Although attention deficit hyperactivity disorder (ADHD) and bipolar disorder (BPD) co-occur frequently and represent a particularly morbid clinical form of both disorders, neuroimaging research addressing this co-morbidity is scarce. Our aim was to evaluate the morphometric magnetic resonance imaging (MRI) underpinnings of the co-morbidity of ADHD with BPD, testing the hypothesis that subjects with this co-morbidity would have neuroanatomical correlates of both ...

OBJECTIVE: Studies examining the relationship between maternal smoking during pregnancy and the development of Attention Deficit Hyperactivity Disorder (ADHD) among offspring have yielded mixed results, with some studies suggesting a strong association and others finding no association. These studies have varied in quality of design and measures. The purpose of this study was to evaluate the association between maternal smoking during pregnancy and offspring ADHD, using detailed ...

ADHD is known to have neuropsychological correlates, characterized mainly by executive function (EF) deficits. However, most available data are based on studies of boys through age 12. Our goal was to assess whether girls with ADHD express neuropsychological features similar to those found in boys, and whether these impairments are found in both preteen and teen samples. Participants were 101 girls and 103 boys with DSM-III-R ADHD, and 109 comparison girls and 70 boys without ADHD, ages ...

BACKGROUND: First-degree relatives of persons with schizophrenia carry elevated genetic risk for the illness and show deficits on high-load information processing tasks. We used functional magnetic resonance imaging (fMRI) to test whether nonpsychotic relatives show altered functional activation in the prefrontal cortex (PFC), thalamus, hippocampus, and anterior cingulate during a working memory task requiring interference resolution.

METHODS: Twelve nonpsychotic relatives of persons ...