We have studied the effect of chronic treatment with imipramine, citalopram and electroconvulsive shock (ECS) on serum and brain zinc levels in rats. Chronic treatment with citalopram (but not with imipramine or ECS) significantly (approx 20%) increased the serum zinc level. Chronic treatment with both drugs slightly (by approx 10%) increase the zinc level in the hippocampus and slightly decreased it in the cortex, cerebellum and basal forebrain. Calculation of the ratio hippocampus/brain region within each group demonstrated a significantly (approx 20%) higher value after treatment with either imipramine or citalopram. Moreover, chronic ECS induced a significant increase (by 30%) in the zinc level in the hippocampus and also a slight increase (by 11-15%) in the other brain regions. Thus, these different antidepressant therapies induced an elevation of the hippocampal zinc concentration, which indicates a significant role of zinc in the mechanism of antidepressant therapy.