This video states that drug addiction is a chronic disease that changes the brain´s chemistry because it triggers a surge of dopamine in the brainś reward system. Dopamine tells your brain that the substance feels good. ItProof of being a cocaine user if they don’t show a picture of the cocaine user and it shows no change in the brain but when they show the user a picture of cocaine the brain receptors rise and the dopamine too. As they were studying how cocaine can damage your brain, they found out that it can trigger small strokes and identified a common trait in most addicts’ share receptors the molecules. another thing is the way drugs affect learning memory.