Acute mental disturbance caused by synthetic cannabinoid: a potential emerging substance of abuse in Hong Kong.

Synthetic cannabinoids are hybrid herbal/chemical products which mimic the effects of cannabis. They are usually marketed as incense or 'herbal smoking blend', and best known by the brand names 'K2' and 'Spice'. Their popularity among recreational drug abusers has grown rapidly due to their easy availability, relatively low cost, non-detection by conventional drug tests, and ease of concealing their use from family and authorities. They took Europe and later North America by storm in the late 2000s, yet limited medical literature exists detailing their adverse effects. They began to emerge in the Hong Kong drug scene in 2009. We report on a man who developed acute mental disturbance after 4 weeks of daily K2 abuse. This is the first case report of mental disorder caused by synthetic cannabinoid abuse in a Chinese.