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.