title: Potential roles of zinc in the pathophysiology and treatment of major depressive disorder.
abstract: Incomplete response to monoaminergic antidepressants in major depressive disorder (MDD), and the phenomenon of neuroprogression, suggests a need for additional pathophysiological markers and pharmacological targets. Neuronal zinc is concentrated exclusively within glutamatergic neurons, acting as an allosteric modulator of the N-methyl D-aspartate and other receptors that regulate excitatory neurotransmission and neuroplasticity. Zinc-containing neurons form extensive associational circuitry throughout the cortex, amygdala and hippocampus, which subserve mood regulation and cognitive functions. In animal models of depression, zinc is reduced in these circuits, zinc treatment has antidepressant-like effects and dietary zinc insufficiency induces depressive behaviors. Clinically, serum zinc is lower in MDD, which may constitute a state-marker of illness and a risk factor for treatment-resistance. Marginal zinc deficiency in MDD may relate to multiple putative mechanisms underlying core symptomatology and neuroprogression (e.g. immune dysfunction, monoamine metabolism, stress response dysregulation, oxidative/nitrosative stress, neurotrophic deficits, transcriptional/epigenetic regulation of neural networks). Initial randomized trials suggest a benefit of zinc supplementation. In summary, molecular and animal behavioral data support the clinical significance of zinc in the setting of MDD.
authors.affiliation: Neuropharmacology Research Group, Sunnybrook Research Institute, Toronto, ON, Canada.
authors.forename: Walter
authors.initials: W
authors.lastname: Swardfager
authors.forename: Nathan
authors.initials: N
authors.lastname: Herrmann
authors.forename: Roger S
authors.initials: RS
authors.lastname: McIntyre
authors.forename: Graham
authors.initials: G
authors.lastname: Mazereeuw
authors.forename: Kyle
authors.initials: K
authors.lastname: Goldberger
authors.forename: Danielle S
authors.initials: DS
authors.lastname: Cha
authors.forename: Yael
authors.initials: Y
authors.lastname: Schwartz
authors.forename: Krista L
authors.initials: KL
authors.lastname: Lanctôt
mesh_terms: D000818:Animals; D003865:Major Depressive Disorder / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D009474:Neurons / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D009435:Synaptic Transmission; D015032:Zinc / Q000378:metabolism* / Q000627:therapeutic use*
chemical_list: D016194:Receptors, N-Methyl-D-Aspartate; D015032:Zinc