Ketamine, a psychoactive ‘party drug’ better known as Special K, has pharma­ceutical companies riding high. Used clinically as an anaesthetic in animals and humans, it has proved an extremely effective treatment for depression, bipolar disorder and suicidal behaviour.

Zarate has found that ketamine seems specifically to affect the desire to attempt suicide, whether a person is clinically depressed or not (E. D. Ballard et al. J. Psychiatr. Res. 58, 161–166; 2014).