Genetic schizophrenia risk variants jointly modulate total brain and white matter volume.

Background: Thousands of common single nucleotide polymorphisms (SNPs) are weakly associated with schizophrenia. It is likely that subsets of disease-associated SNPs are associated with distinct heritable disease-associated phenotypes. Therefore, we examined the shared genetic susceptibility modulating schizophrenia and brain volume.

Tract-based diffusion tensor imaging in patients with schizophrenia and their non-psychotic siblings.

Structural brain abnormalities have consistently been found in patients with schizophrenia. Diffusion tensor imaging (DTI) has been shown to be a useful method to measure white matter (WM) integrity in this illness, but findings in the earlier disease stages are inconclusive. Moreover, the relationship between WM microstructure and the familial risk for developing schizophrenia remains unresolved.

Genetic Risk and Outcome of Psychosis (GROUP), a multi-site longitudinal cohort study focused on gene-environment interaction: objectives, sample characteristics, recruitment and assessment methods.

Objective: A longitudinal focus on gene-environment vulnerability and resilience in both patients, their unaffected family members and non-related controls offers the opportunity to elucidate etiological and pathogenetic factors influencing the onset and course of psychotic disorders. The current paper delineates the objectives, sample characteristics, recruitment and assessment procedures of the Genetic Risk and Outcome of Psychoses (GROUP) study.

Methods: A naturalistic longitudinal cohort study with assessments at baseline, after three and six years of follow-up.

Focal and global brain measurements in siblings of patients with schizophrenia.

Background: It remains unclear whether structural brain abnormalities in schizophrenia are caused by genetic and/or disease-related factors. Structural brain abnormalities have been found in nonpsychotic first-degree relatives of patients with schizophrenia, but results are inconclusive. This large magnetic resonance imaging study examined brain structures in patients with schizophrenia, their nonpsychotic siblings, and healthy control subjects using global and focal brain measurements.

Brain volumes in relatives of patients with schizophrenia: a meta-analysis.

Context: Smaller brain volumes have consistently been found in patients with schizophrenia, particularly in gray matter and medial temporal lobe structures. Although several studies have investigated brain volumes in nonpsychotic relatives of patients with schizophrenia, results have been inconsistent.

Objective: To determine the magnitude and extent of brain volume differences in first-degree relatives of schizophrenic patients.