Cannabis, from the Indian hemp plant, is the most commonly used psychoactive substance in the world and has a long history of medicinal, recreational and industrial use. Globally, cannabis is by far the most widely cultivated, trafficked and abused illicit drug. Cannabis has two powerful active ingredients – THC and CBD (cannabidiol) and both substances are classed as cannabinoids. The substances produce psychoactive effects by binding with special receptors which are extraordinarily abundant all over the brain and body. Synthetic cannabinoids are psychoactive (mind-altering) substances design to mimic or produce similar effects to cannabis. Synthetic cannabinoids are included in a group of drugs called “new psychoactive substances” (NPS). Research evidence has shown that the ingredients in cannabis have therapeutic value for a number of conditions including anti-seizure, antioxidant, neuroprotective, anti-inflammatory, analgesic, anti-tumor, anti-psychotic and anti-anxiety properties. The considerable debate has been whether cannabis use causes psychotic symptoms and whether cannabis use may precipitate psychosis in individuals predisposed to acquiring a psychotic disorder. On the basis of current research, cannabis cannot be said to provide as clear a withdrawal pattern as other drugs of misuse, such as opiates.