Dopamine is one of the most important neurotransmitters in the human body. It plays a critical role in the central nervous system, and it is responsible for regulating a wide variety of body processes. It is a member of the catecholamine and phenethylamine families. It is made from its precursor, L-DOPA, which is made in the kidneys and brain. Dopamine is released by neurons in the central nervous system and is used to transmit signals to other cells throughout the body. Dopamine is involved in the reward processes of the brain, meaning that it can play a role in addictive behavior. Many mental health treatments target dopamine receptors and production as well. Dopamine has also been closely linked to internal motivation. When dopamine is outside of the central nervous system, it functions as a local messenger, playing a role in the cardiovascular and gastrointestinal systems. Treatments involving dopamine are used to treat Parkinson's disease, nausea, restless leg syndrome, ADHD, and acute cardiovascular issues, including shock and heart failure.