Treatment resistant depression remains a significant problem for psychiatry. Where all other treatments have failed; ECT can be highly effective. However, this is associated with a negative impact on episodic and autobiographical memory. The NMDA antagonist ketamine has been demonstrated to have a rapid although short lived antidepressant effect following a single administration. However, memory performance is known to be impaired in volunteers when ketamine is given acutely and in those who regularly abuse high doses recreationally. In a recent study, researchers from NDCN, Psychiatry, the Centre for Statistics in Medicine and the Oxford NHS Trusts have investigated the safety and efficacy of repeated ketamine infusions in patients who continued other psychotropic medication, with particular emphasis on memory functioning. Writing in the Journal of Psychopharmacology Diamond et al., reported that up to six low dose ketamine infusions can safely be given within an existing NHS clinical structure to patients who continue their antidepressants. Ketamine was not associated with memory impairment. The response rate was comparable to that seen with single doses of ketamine in antidepressant-free patients but took slightly longer to develop. Lead researcher Dr Rupert McShane said: "It really is dramatic for some people, it's the sort of thing really that makes it worth doing psychiatry, it's a really wonderful thing to see”
However, much more research is needed into its safety and effectiveness before it is known whether ketamine could one day be licensed for treatment of depression.