Analysis of Plasma Zinc and Copper Concentration, and Perceived Symptoms, in Individuals with Depression, Post Zinc and Anti-Oxidant Therapy

Aim: To assess plasma Zn and Cu levels in individuals with depression. Subjects and methods: Plasma from 73 clinically depressed individuals, 38 individuals with anxiety and 16 controls were tested for plasma Zn and Cu concentration using inductively-coupled plasma-mass spectrometry. Results: Depressed individuals, with and without secondary anxiety, had decreased plasma Zn and elevated plasma Cu compared to controls. Zn normalized (increased to the level of normal controls) but Cu increased in individuals with depression (with and without secondary anxiety), after Zn therapy, whereas both plasma Zn increased and Cu levels decreased in anxiety, with and without secondary depression, after Zn therapy. Individuals with depression,with and without secondary anxiety, had significantly higher symptom severity when compared to neurotypical controls. Symptom severity in individuals with anxiety (both with and without secondary depression) significantly decreased after Zn therapy, whereas symptoms remained the same in individuals with primary depression. Discussion: These data show an association between Zn and Cu plasma levels and clinically depressed individuals, and suggest that high Cu levels are associated with high symptom severity.