The adverse effects of marijuana use: The present state and future directions

Abstract Marijuana is recently a subject of a global debate due to potential medical application of cannabis products and the progressive legalization of its recreational use. This situation leads to the need for access to comprehensive and reliable information about the effects of marijuana intake. Our review presents the actual state of knowledge regarding acute and chronic health effects generated by recreational marijuana use. Marijuana smoking can lead to structural and functional alterations in the central nervous system. These effects are especially significant and dangerous at the prenatal, child, and adolescence periods. In contrary to a common myth, cannabis does exhibit an addictive potency, albeit not a strong one. We discuss the “cannabis gateway hypothesis,” which suggests that marijuana use can be the first step before trying more dangerous drugs. However, drawing significant conclusions is difficult due to the strong impact of confounders and often unclear relationships among studied factors, especially in the socioeconomic context. Moreover, we point to the need for the unbiased assessment of the harm generated by marijuana in comparison with other drugs.