RESUMO
Worldwide more than 3 million deaths a year are attributable to smoking, and tobacco use is on the rise in developing countries. Consequently, smoking is one of the few causes of mortality that is increasing, with deaths projected to reach 10 million annually in 30-40 years. Cannabinoids, which are usually used in the form of marijuana, have become the most frequently used illicit drugs, but there is no pharmacological treatment for marijuana dependence. Although the dopaminergic system plays a critical role in reinforcing the effects of drugs of abuse, other neurotransmitter systems are also involved. Here we review recent results obtained with antagonists targeting cannabinoid CB1 receptors, dopamine D3 receptors and opioid receptors, that directly or indirectly modulate dopaminergic transmission. These promising approaches warrant clinical trials in the treatment of tobacco and marijuana dependence.