MDA may intensify stress in PTSD and progress dysthymic disorders into major depression through several mechanisms: inhibition of neurogenesis via BDNF-related signaling in the hippocampus, promotion of inflammation by microglial activation and increased pro-inflammatory cytokine production, mitochondrial dysfunction through respiratory chain damage, decreased ATP production, and enhanced ROS generation. The gene discussed is BDNF; the disease is dysthymic disorder.