Ketamine is increasingly known as a party drug which is linked to serious health problems, even fatalities.
But there is growing interest in Scotland in its potential to treat severe depression.
One NHS Lothian psychiatrist hopes to set up a clinic by the end of the year offering the Category B drug as an alternative to electroconvulsive therapy (ECT), a treatment that involves sending an electric current through the brain.
Prof Andrew McIntosh thinks it could offer another alternative to patients with the most hard-to-treat depression.
The move comes after a private clinic in Lanarkshire began offering ketamine assisted therapy to clients with treatment-resistant depression last summer.
