A paper published in the New England Journal of Medicine found that in patients with treatment-resistant depression, esketamine nasal spray was more effective than quetiapine, an anti-psychotic medication.

Both drugs were taken alongside an SSRI (selective serotonin reuptake inhibitor) or SNRI (serotonin and norepinephrine reuptake inhibitors). Patients on Esketamine had higher rates of remission at both eight weeks and 32 weeks, with fewer negative side effects reported.

The paper follows a decision by the National Institute for Clinical Excellence (NICE) in England to decide against recommending esketamine nasal spray for treatment-resistant depression.

Associate Professor McShane, who leads Oxfordshire ECT and ketamine services and runs the memory clinic, was not an author on the paper but published an editorial in the journal alongside it. He said:

“When antidepressants do not work, esketamine nasal spray would be a useful alternative, particularly for those for whom weight gain or sedation are problematic.  However, esketamine is expensive and we do not have good information on how long you need to keep taking it.  It will not be available on the NHS until NICE have approved it.

“Recent trials also suggest that intravenous (IV) ketamine would be as effective as Electro Convulsive Therapy (ECT), especially in those under 50, and does not have enduring side effects.  So, IV ketamine could also be a way of helping people with more severe depression.”

When used frequently in high doses without medical supervision, ketamine is addictive and can cause severe bladder damage. It has not been found to cause bladder damage and is not addictive when used in low doses and under medical supervision.

“While I do understand concerns about ketamine, NHS mental health trusts are in a good position to manage it. I don’t think it would lead to services being overwhelmed,” said Professor McShane.

Professor McShane works for Oxford Health NHS Foundation Trust and for Oxford University’s Department of Psychiatry.