Cocaine is a potent cathecholamine agonist that is highly addictive. It increases the activity of both dopamine and nirepinephrine by blocking their reuptake from the synapse into the presynaptic button. Accordingly, when there are high levels of cocaine in the brain, molecules of dopamine and norepineprine, once released into the synapse, continue to activate postsynaptic receptors because their primary method of deactivation has been blocked. This produces a variety of psychological effects, including euphoria, loss of appetite, and insomnia. It is also responsible for the addictive potential of cocaine.