Dopamine

Dopamine is both an excitatory and inhibitory neurotransmitter (chemical messenger) that regulates the body’s pleasure/reward systems. Itcommunicates among neurons within the brain and the rest of the body. In a healthy brain, dopamine helps motivate learning, meeting new people, or trying new experiences. It’s involved in mood, control of complex movements, and memory, behavior, cognition, attention, sleep, arousal, and learning. Dopamine is associated with the brain’s mechanisms for pleasurable reward and motivation. Substances like cocaine, heroin, and alcohol can temporarily increase their levels in the blood and can become addictive. Over time, addiction can deplete the brain’s dopamine stores, making it difficult to feel pleasure without drugs. This is why many people with addictions find little relief from activities that were once pleasurable. Dopamine is also a neurohormone (with epinephrine and norepinephrine) released in the bloodstream. It plays a small role in fight-or-flight response (FFR) and other physiological roles (relaxes/constricts blood vessels, increases sodium removal, reduces insulin production). Medications for anxiety and mood disorders work by modifying how dopamine acts in the brain.