Abstract
Illicit substance use disorder is a chronic brain disease. This disease can lead to many negative health outcomes or even death. Recently, Saudi Arabia's rank was among the top of the world in amphetamine seizures. Drug smuggling as well as conflicts and wars in the surrounding countries might play a role in that. The current paper aimed to review the over time prevalence of illicit substance use in Saudi Arabia. To achieve that, we searched through different databases. We also looked over the United Nations Office on Drugs and Crime (UN-ODC) reports. The current review found a few articles talking about illicit substance use prevalence in Saudi Arabia; much of that work was about Khat substance. In the end, we concluded that there is a considerable need for further research in this field.