Mererid Velios

Both stimulants activate the sympathetic and central nervous systems to heighten arousal, increase behavioural activation and the so‐called rush followed by a long‐lasting state of euphoria. They increase the level of norepinephrine (noradrenalin) and dopamine in the synapse. As part of the brain's reward circuit, dopamine neurons play a critical role in drug craving. Repeated drug use changes the way that neurons in the reward circuit process information. The end result is a fundamental change in brain circuitry that increases the likelihood of addiction.