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Study: Illegal drug could be 'dramatic' depression therapy

Ketamine, an illegal party drug, could be used as a "dramatic" new treatment for depression. 

By giving patients low doses of the drug, researchers found that patients who  had depression for decades had symptoms disappear within hours. 

The study, published in the Journal of Psychopharmacology, showed that ketamine is a fast-acting antidepressant which worked in patients with depression that had not responded to other treatments. 

Many patients symptoms of depression returned within a few days, but a third went without depression for at least three weeks, and 15% were without any symptoms of depression for more than two months. 

In the Oxford University study, 28 patients were treated over three weeks. were given either three or six ketamine infusions lasting 40 minutes over three weeks.

Patients reported their mood symptoms daily via text or email. The antidepressant response sometimes took a second ketamine infusion to become apparent. 

However, three days after the last infusion, the depression scores had halved in 29% of the patients. In those that responded to the treatment, the duration of benefit varied widely, lasting between 25 days and eight months.

Lead author Dr Rupert McShane said: "We wanted to see whether it would be safe if given repeatedly, and whether it would be practical in an NHS setting. We especially wanted to check that repeated infusions didn't cause cognitive problems

"We've seen remarkable changes in people who've had severe depression for many years that no other treatment has touched. It's very moving to witness. Patients often comment that that the flow of their thinking seems suddenly freer. For some, even a brief experience of response helps them to realise that they can get better and this gives hope."

The small study was funded by National Institute for Health Research (NIHR) Research for Patient Benefit Programme.

Ketamine in the process of being reclassified as a class B drug, although it is already used in medicine for the treatment of back pain and as an anaesthetic.