DAOA variants on diagnosis and response to treatment in patients with major depressive disorder and bipolar disorder

Objective: This study investigated whether selected D-amino acid oxidase activator (DAOA) gene single nucleotide polymorphisms (SNPs; rs3916966, rs3916967, rs2391191, rs3916968, rs7139958, rs9558571, rs778293) are associated with major depressive disorder (MDD) and bipolar disorder (BD), and whether they can predict clinical outcomes in Korean in-patients treated with antidepressants and mood stabilizers, respectively. Methods: In total, 145 patients with MDD, 132 patients with BD and 170 psychiatrically healthy controls were genotyped for the DAOA SNPs. Baseline and final clinical assessments included the Montgomery- Asberg Depression Rating Scale and Young Mania Rating Scale for patients with MDD and BD, respectively. Results: There was no association between DAOA SNP genotypes or alleles with diagnosis, clinical improvement, response rates or remission rates for MDD and BD. Haplotype analyses found no association with MDD or BD diagnosis or clinical outcomes. Conclusion: The findings suggest that the DAOA SNPs investigated may not affect MDD or BD phenotype, clinical symptoms or other clinical factors, and are unlikely to be involved in MDD or BD development and treatment outcomes. Given the study's limitations, further investigation should be carried out.