ABSTRACT
<p><b>OBJECTIVE</b>To assess the effects of apolipoprotein E (APOE) polymorphism on the susceptibility of depression and the efficacy of antidepressants.</p><p><b>METHODS</b>A total of 275 patients with depression, who met the diagnostic criteria of both CCMD-3 and DSM-4, were randomly assigned into venlafaxine group (n=136)and paroxetine group(n=139). Another 202 healthy subjects were enrolled as the control group. Hamilton Rating Scale for Depression (HAMD)-17 was adopted as the primary rating instrument to evaluate the severity of depression on the baseline and the end of the 1st, 2nd, 4th, 6th week after treatment, respectively. HAMD scores ≤7 was defined as remission, and the reduction of HAMD scores ≥50% was defined as response while <50% was defined as invalid. PCR-restriction fragment length polymorphisms (PCR-RFLP) was applied to detect the genetic polymorphism of the APOE in the case groups and control group.</p><p><b>RESULTS</b>In the venlafaxine group, the remission rate was 52.9%(n=72), the response rate was 26.5%(n=36), and the invalid rate was 20.6%(n=28), whereas the corresponding data in the paroxetine group wee 42.4%(n=59), 31.7%(n=44), and 25.9% (n=36), respectively. There were no significant differences in the efficacy between the two groups(p>0.05). In the venlafaxine group, there were no significant differences in the genotypes and the allele distribution frequency of APOEΕ2/Ε3/Ε4 between the remitters, nonremitters, and healthy controls at the end of the 6th week(p>0.05), but there was significant differences in the allele distribution frequency between the nonremitters and healthy controls(p=0.02). In paroxetine group, there were no significant differences in the genotypes and the allele distribution frequency of APOEΕ2/Ε3/Ε4 among the remitters, nonremitters and healthy controls at the end of the 6th week(p>0.05), but there were significant differences in the allele distribution frequency between the nonremitters and healthy controls (p=0.04); in addition, there were also significant differences in Ε2/Ε3 and Ε4 allele between the two groups (p=0.014).</p><p><b>CONCLUSIONS</b>The APOE gene may not play a major role in the pathogenesis of major depression. The efficacy of venlafaxine is same as paroxetine after treatment for six weeks. The APOE (Ε2+Ε3) allele may be an indicator of the bad efficacy of paroxetine treatment.</p>