Prior trials suggest that intravenous racemic ketamine is a highly effective for treatment-resistant depression (TRD), but phase 3 trials of racemic ketamine are needed.

To assess the acute efficacy and safety of a 4-week course of subcutaneous racemic ketamine in participants with TRD. Trial registration: ACTRN12616001096448 at www.anzctr.org.au.

This phase 3, double-blind, randomised, active-controlled multicentre trial was conducted at seven mood disorders centres in Australia and New Zealand. Participants received twice-weekly subcutaneous racemic ketamine or midazolam for 4 weeks. Initially, the trial tested fixed-dose ketamine 0.5 mg/kg versus midazolam 0.025 mg/kg (cohort 1). Dosing was revised, after a Data Safety Monitoring Board recommendation, to flexible-dose ketamine 0.5–0.9 mg/kg or midazolam 0.025–0.045 mg/kg, with response-guided dosing increments (cohort 2). The primary outcome was remission (Montgomery-Åsberg Rating Scale for Depression score ≤10) at the end of week 4.

The final analysis (those who received at least one treatment) comprised 68 in cohort 1 (fixed-dose), 106 in cohort 2 (flexible-dose). Ketamine was more efficacious than midazolam in cohort 2 (remission rate 19.6% v. 2.0%; OR = 12.1, 95% CI 2.1–69.2, P = 0.005), but not different in cohort 1 (remission rate 6.3% v. 8.8%; OR = 1.3, 95% CI 0.2–8.2, P = 0.76). Ketamine was well tolerated. Acute adverse effects (psychotomimetic, blood pressure increases) resolved within 2 h.

Adequately dosed subcutaneous racemic ketamine was efficacious and safe in treating TRD over a 4-week treatment period. The subcutaneous route is practical and feasible.

Public and patient expectations of treatment influence health behaviours and decision-making.

We aimed to understand how the media has portrayed the therapeutic use of ketamine in psychiatry.

We systematically searched electronic databases for print and online news articles about ketamine for psychiatric disorders. The top ten UK, USA, Canadian and Australian newspapers by circulation and any trade and consumer magazines indexed in the databases were searched from 2015 to 2020. Article content was quantitatively coded with a framework encompassing treatment indication, descriptions of prior use, references to research, benefits and harms, treatment access and process, patient and professional testimony, tone and factual basis.

We found 119 articles, peaking in March 2019 when the United States Food and Drug Administration approved esketamine. Ketamine treatment was portrayed in an extremely positive light (n = 82, 68.9%), with significant contributions of positive testimony from key opinion leaders (e.g. clinicians). Positive research results and ketamine's rapid antidepressant effect (n = 87, 73.1%) were frequently emphasised, with little reference to longer-term safety and efficacy. Side-effects were frequently reported (n = 96, 80.7%), predominantly ketamine's acute psychotomimetic effects and the potential for addiction and misuse, and rarely cardiovascular and bladder effects. Not infrequently, key opinion leaders were quoted as being overly optimistic compared with the existing evidence base.

Information pertinent to patient help-seeking and treatment expectations is being communicated through the media and supported by key opinion leaders, although some quotes go well beyond the evidence base. Clinicians should be aware of this and may need to address their patients’ beliefs directly.