Serum selenium unrelated to depression, but supplementation could prove protective

High selenium intake seems to exert a significant protective effect against postpartum depression, reports a recent meta-analysis. Selenium may be considered as a potential adjuvant therapy in patients with depression.

A total of 20 studies were retrieved from the online databases of Scopus, Medline, Web of Science, the WHO Global Index Medicus, and ClinicalTrials.gov. Of the studies included in the review, 15 were deemed eligible for quantitative meta-analysis, yielding a total sample size of 45,795 participants.

Pooled analysis revealed no significant link between depression scores and serum selenium concentrations (r, –0.12, 95 percent confidence interval [CI], –0.33 to 0.08). There was also no significant difference in serum selenium between healthy controls and patients with depression (weighted mean difference [WMD], 2.12 mg/L, 95 percent CI, –0.11 to 4.36).

Seven studies looked at the impact of selenium intake on the risk of depression and found no significant difference between the highest vs lowest levels of intake (odds ratio [OR], 0.98, 95 percent CI, 0.93–1.04).

Strong and significant heterogeneity of evidence warranted subgroup analyses, which found that higher selenium intake could significantly suppress the likelihood of postpartum depression (OR, 0.97, 95 percent CI, 0.95–0.99). No such effect was found for other types of depression (OR, 1.06, 95 percent CI,0.75–1.50).

Three studies then looked at the impact of selenium supplementation on depression scores and found a significant benefit compared with placebo (WMD, –0.37, 95 percent CI, –0.56 to –0.18), without significant heterogeneity of evidence.