CYP2C19 polymorphisms are associated with severity of depression at initial evaluation and after the treatment independently of the prescribed medications: 4 weeks prospective study

CYP2C19-rs4986893 confers risk to major depressive disorder and bipolar disorder in the Han Chinese population whereas ABCB1-rs1045642 acts as a protective factor

BACKGROUND

Genetic risks may predispose individuals to major mood disorders differently. This study investigated the gene polymorphisms of previously reported candidate genes for major depressive disorder (MDD) and bipolar disorder (BPD) in the Han Chinese population.

METHODS

Twenty loci of 13 candidate genes were detected by MALDI-TOF mass spectrometry in 439 patients with MDD, 600 patients with BPD, and 464 healthy controls. The distribution of genotypes in alleles, Hardy-Weinberg equilibrium, and genetic association were analyzed using the PLINK software. The linkage of disequilibrium and haplotype analyses were performed using the Haploview software.

RESULTS

Out of the 20 loci analyzed, CYP2C19-rs4986893, ABCB1-rs1045642, and SCN2A-rs17183814 passed Bonferroni correction; their statistical powers were > 55%. The minor allele frequencies (MAF) of CYP2C19-rs4986893 in the MDD group (0.0547) and BPD group (0.0533) were higher than that of the control group (0.0259, P < 0.05), leading to the odds ratios (ORs) of MDD (2.178) and BPD (2.122), respectively. In contrast, the lower MAFs of ABCB1-rs1045642 were observed in both MDD (0.3599, OR = 0.726) and BPD (0.3700, OR = 0.758) groups than controls (0.4364, P < 0.05). The MDD group had a higher MAF of SCN2A-rs17183814 than controls (0.1743 vs. 0.1207, OR = 1.538, P < 0.05). Moreover, a G-A haplotype composed by CYP2C19-rs4986893 and -rs4244285 was associated with BPD (OR = 1.361, P < 0.01), and the A-G haplotype increased the risks to both MDD (OR = 2.306, P < 0.01) and BPD (OR = 2.332, P < 0.001). The CYP2C19 intermediate metabolizer and poor metabolizer (IM&PM) status was related to the raised risk of both MDD (OR = 1.547, P < 0.01) and BPD (OR = 1.808, P < 0.001).

CONCLUSION

Our data indicate that the impaired CYP2C19 metabolism caused by the haplotypes integrated by CYP2C19 alleles might confer the risk to MDD and BPD, whereas the ABCB1-rs1045642 T allele serves as a protective factor.

CYP2C19 slow metabolizer phenotype is associated with lower antidepressant efficacy and tolerability

The inter-individual variability in CYP2C19-mediated metabolism may affect the antidepressant treatment. The aim of this study is to evaluate differences in antidepressant efficacy and tolerability between different CYP2C19 metabolizer categories in inpatients suffering from major depressive disorder. The cohort was divided into experimental groups based on CYP2C19 genotype and it contained 24 slow (SMs), 41 normal (NMs), and 37 fast metabolizers (FMs). Efficacy and tolerability were assessed at baseline, and after two and four weeks as a follow-up. The primary efficacy measurement was the change from baseline in Hamilton's Depression Rating Scale (HAMD), while the primary tolerability measurement was the Toronto Side-Effects Scale (TSES) intensity scores at the last visit. The reduction in HAMD score was 36% less pronounced and response rate was exceedingly less prevalent (75% lower) in SMs, compared with NMs. The TSES intensity score was increased in SMs, compared with NMs, by 43% for central nervous system and by 22% for gastrointestinal adverse drug reactions. No significant differences in measured parameters were observed between NMs and FMs. Compared with NM and RM, lower antidepressant efficacy and tolerability was observed in SMs; this association is likely connected with the lower SM capacity to metabolize antidepressant drugs.