"Legal highs" - new players in the old drama.

Recently, a new class of "designer drugs" has emerged on the drug use market, known as "legal highs" or "herbal highs". They include a wide range of products, from natural plant-originated substances to synthetic compounds, that can be purchased both online and from high street retailers. "Legal highs" mimic psychoactive effects of illicit drugs of abuse. However, they are claimed to consist of compounds that are legal to sell, possess and use. Based on the spectrum of their actions on the cognitive processes, mood, and behavior "legal highs" can be classified into three basic categories: amphetamine- and ecstasy-like psychostimulants, hallucinogens, and synthetic cannabinoids ("spice"). This review surveys the current state of knowledge regarding the pharmacological properties of "legal highs". It also addresses the negative consequences of using these products.