Testosterone May Hold Therapeutic Promise for the Treatment of Ischemic Stroke in Aging: A Closer Look at Laboratory Findings

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

BACKGROUND

The cytochrome P-450 2C19 (CYP2C19) enzyme is involved in the metabolism of numerous antidepressants. It also metabolises some endogenous substrates, which could also confer to vulnerability. We aimed to establish whether the severity of depression and treatment response are associated with the genetically predicted CYP2C19 phenotype.

METHODS

We assessed the CYP2C19 genotype-predicted metabolic phenotypes (normal, intermediate or ultrarapid, there were no poor metabolisers) in patients with moderate or severe depression. We used the self-rated Beck Depression Inventory-II (BDI-II) scale and the clinician-rated Montgomery-Åsberg Depression Rating Scale (MADRS) at baseline, after 2 and 4 weeks of an empirical treatment trial. Patients and clinicians were blind to the genetic testing results.

RESULTS

Seventy-six patients participated in the present study. At baseline, impaired CYP2C19 metabolisers, compared to normal metabolisers, had higher BDI-II (P = 0.046; ηp2 = 0.08) but not MADRS score. Intermediate metabolisers more often had a diagnosis of severe depression than normal metabolisers (P = 0.003). After 4 weeks of empirical treatment, intermediate metabolisers had significantly higher MADRS and BDI-II scores than normal metabolisers (P = 0.006; ηp2  = 0.131 and P = 0.030; ηp2 = 0.091). These differences were independent of the use of CYP2C19-metabolised medications in the treatment trial, as well as the treatment discrepancy status.

CONCLUSIONS

Intermediate CYP2C19 polymorphism-predicted activity was associated with more severe depression after an empirical treatment trial. The lack of association between the prescription of CYP2C19-metabolised drugs and treatment response calls for a further look into the role of endogenous substrates of CYP2C19.

Sex differences in the response to oxidative and proteolytic stress

Sex differences in diseases involving oxidative and proteolytic stress are common, including greater ischemic heart disease, Parkinson disease and stroke in men, and greater Alzheimer disease in women. Sex differences are also observed in stress response of cells and tissues, where female cells are generally more resistant to heat and oxidative stress-induced cell death. Studies implicate beneficial effects of estrogen, as well as cell-autonomous effects including superior mitochondrial function and increased expression of stress response genes in female cells relative to male cells. The p53 and forkhead box (FOX)-family genes, heat shock proteins (HSPs), and the apoptosis and autophagy pathways appear particularly important in mediating sex differences in stress response.