Figure 2: This figure shows that substance abuse ultimately leads to neuroinflammation associated with neuronal damage through the production of inflammatory factors by glial cells. Methamphetamine, opioids, and cocaine activate microglia and astrocytes by producing DAQ, ROS, and NO. Activated microglia and astrocytes increase interleukin production, promoting neuroinflammation and neuronal damage. Damaged neurons release DAMPs that act on microglia and exacerbate inflammation and eventual neurotoxicity through a positive feedback mechanism.