Association between the Epidermal Growth Factor Gene and Intelligence in Major Depression Patients

Objective To study the association between the epidermal growth factor(EGF) gene and intelligence in patients with major depression.Methods Intelligence measurement using Wechsler Adult Intelligence Scale(WAIS) was perfor-med on 120 unrelated patients with major depression and 46 control subjects.Blood was collected from all subjects for extraction of genomic DNA.Four single nucleotide polymorphisms(SNPs) in the EGF gene were genotyped using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS).Results Mean scores of both score lang and score task,two subtests in WAIS,differed significantly between major depression patients and controls(P<0.0001).Quantitative trait analysis showed that the genetype of rs2250724 was closely associated with score lang and score task in major depression patients.The associations were still significant after 10 000 permutations.Conclusions Although preliminary,our results provide evidence for association between the EGF gene and intelligence in patients with major depression.Genetic variation in the EGF gene may increase the susceptibility of major depression.

The DIRECT consortium and the REST-meta-MDD project:towards neuroimaging biomarkers of major depressive disorder

Despite a growing neuroimaging literature on the pathophysiology of major depressive disorder(MDD),repro-ducible findings are lacking,probably reflecting mostly small sample sizes and heterogeneity in analytic approaches.To address these issues,the Depression Imaging REsearch ConsorTium(DIRECT)was launched.The REST-meta-MDD project,pooling 2428 functional brain images processed with a standardized pipeline across all participating sites,has been the first effort from DIRECT.In this review,we present an overview of the moti-vations,rationale,and principal findings of the studies so far from the REST-meta-MDD project.Findings from the first round of analyses of the pooled repository have included alterations in functional connectivity within the default mode network,in whole-brain topological properties,in dynamic features,and in functional lat-eralization.These well-powered exploratory observations have also provided the basis for future longitudinal hypothesis-driven research.Following these fruitful explorations,DIRECT has proceeded to its second stage of data sharing that seeks to examine ethnicity in brain alterations in MDD by extending the exclusive Chinese original sample to other ethnic groups through international collaborations.A state-of-the-art,surface-based preprocessing pipeline has also been introduced to improve sensitivity.Functional images from patients with bipolar disorder and schizophrenia will be included to identify shared and unique abnormalities across diag-nosis boundaries.In addition,large-scale longitudinal studies targeting brain network alterations following antidepressant treatment,aggregation of diffusion tensor images,and the development of functional magnetic resonance imaging-guided neuromodulation approaches are underway.Through these endeavours,we hope to accelerate the translation of functional neuroimaging findings to clinical use,such as evaluating longitudinal effects of antidepressant medications and developing individualized neuromodulation targets,while building an open repository for the scientific community.