A ketamine pill may help hard-to-treat depression with fewer side effects, early research suggests CNNExtended-release ketamine tablets for treatment-resistant depression: a randomized placebo-controlled phase 2 trial Nature.comSlow-release ketamine tablets help prevent depression relapses, UK trial finds The GuardianElon Musk-backed ketamine therapy offers hope to patients with severe depression where other medication fails Daily MailKetamine tablets help reduce side-effects in depression sufferers Financial Times