Abstract
Marihuana is one of the most frequently abused illicit drugs among adolescents and young adults. As such, exposure to psychoactive ingredients, with delta 9-tetrahydrocanabinol (THC) being the most prevalent, collide with critical periods of brain development.
Firstly, in mothers who cease to abuse cannabis at the onset of pregnancy, THC and other lipid-soluble substances might still circulate in their blood at levels that may interfere with the brain development of the fetus. This is due to the chemical nature of THC and related substances; these are lipophilic and accumulate in the body fat.
During pregnancy, the fat redistribution leads to release of cannabinoids into the blood stream. These substances readily cross placental barrier and enter fetal circulation.
The second period of brain maturation that is influenced by THC exposure in many smokers is during puberty and is associated with an increased risk of neuropsychiatric consequences. The third negative aspect of cannabis abuse giving rise to neurodevelopmental disturbances is related to the "quality" of the newly developed species of the cannabis sativa plant with as much as 25 times higher concentration of THC than in the samples obtained a decade ago, not mentioning the availability of new synthetic cannabinoid-like ligands of obscure, usually Chinese origin.
Legalization of cannabis may be beneficial in certain medical indications but, on the other hand, it might bring false anticipation of harmlessness. The purpose of this review article is to discuss potential side effects of marihuana use during periods of nervous system development both in utero and in adolescence.