Approximately 10,000 suicide deaths are recorded in Brazil every year. The suicide risk is highest among patients with depressive disorders, particularly women (> 18% vs. 11% for men).
There are countless people who work to prevent suicide, and the challenges they face are many. But now, on the horizon, there are new tools that could prove invaluable to their efforts – tools such as biomarkers. In a study recently published in the journal Frontiers in Psychiatry, researchers from the Catholic University of Pelotas (UCPel), Brazil, reported an association of glutathione (GSH) with the degree of suicide risk in women at 18 months postpartum. Specifically, they found that reduced serum GSH levels were significantly lower for those with moderate to high suicide risk than for those without suicide risk. Their findings suggest that GSH may be a potential biomarker or etiologic factor among women at risk for suicide, with therapeutic implications.
This was a case-control study nested within a cohort study. From this cohort, 45 women were selected at 18 months postpartum. Thirty of them had mood disorders, such as major depression and bipolar disorder. The other 15 participants, none of whom had a mood disorder, made up the control group.
Depression and the risk for suicide were assessed using the Mini International Neuropsychiatric Interview Plus (MINI-Plus 5.0.0 Brazilian version), module A and module C, respectively. Blood samples were collected to evaluate serum levels of the following oxidative stress biomarkers: reactive oxygen species, superoxide dismutase, and GSH.
The prevalence of suicide risk observed in the women at 18 months postpartum was 24.4%. The prevalence of suicide risk in the mood disorder group was 36.7%.
In addition, the statistical analysis found that women with moderate to high suicide risk had cerebral redox imbalance, resulting in a decrease in blood GSH levels.
The study team was led by neuroscientist Adriano Martimbianco de Assis, PhD, the coordinator of UCPel’s postgraduate program in health and behavior. He said that the correlation identified between GSH serum levels and suicide risk gives rise to two possible applications: using GSH as a biomarker for suicide risk and using GSH therapeutically.
Regarding the former application, Dr. Martimbianco de Assis explained that additional studies are needed to take a step forward. “Although we believe that most of the GSH came from the brain – given that it’s the brain’s main antioxidant – as we analyze blood samples, we’re not yet able to rule out the possibility that it came from other organs,” he said in an interview. So, confirming that hypothesis will require studies that involve imaging brain tissue. According to Dr. Martimbianco de Assis, once there is confirmation, it will be possible to move to using the antioxidant as a biomarker for suicide risk.
He also shared his views about the second application: using GSH therapeutically. “We already know that there are very simple alternatives that can influence GSH levels, [and they] mostly have to do with exercise and [improving the quality of] the food one eats. But there are also drugs: for example, N-acetyl cysteine, which is a precursor of GSH.” Adopting strategies to increase the levels of this antioxidant in the body should reverse the imbalance identified in the study and, as a result, may lead to lowering the risk for suicide. But, he reiterated, “getting to a place where GSH [can be used] in clinical practice hinges on getting that confirmation that it did, in fact, come from the brain. Recall that our study found lower levels of GSH in women at risk for suicide.”
Even though the study evaluated postpartum women, it’s possible that the results can be extrapolated to other populations, said Dr. Martimbianco de Assis. This is because when the data were collected, 18 months had already passed since giving birth. The participants’ physiological condition at that point was more similar to the one prior to becoming pregnant.
The UCPel researchers continue to follow the cohort. “We intend to continue monitoring GSH levels at other times. Forty-eight months have now passed since the women gave birth, and the idea is to continue studying [the patients involved in the study],” said Dr. Martimbianco de Assis, adding that the team also intends to analyze brain tissue from in vitro studies using cell cultures.
This article was translated from the Medscape Portuguese Edition and a version appeared on Medscape.com.