These findings in post-mortem analysis of patients with depression and also those treated with antidepressants provide an optimistic outlook for the future treatment of patients afflicted with depression. These studies have enabled us to have a better understanding of how depression affects key structures in the limbic system of the brain, and they have also revealed that treatment with antidepressants does reverse those effects. Antidepressants enable BDNF and its signaling pathways to enhance synaptic plasticity. This evidence concerns the gene BDNF and depressive symptom measurement.