Students at Britain’s prestigious Cambridge University were paid $387 to take part in a psychiatric study in which they were injected with the horse tranquillizer ketamine.

The research, carried out by the university’s department of psychiatry, was designed to investigate treatment methods for schizophrenia, the Cambridge News reported Monday.

People suffering from the mental illness sometimes believe that external objects have become part of their body — a sensation also experienced by ketamine users.

Researchers injected 15 participants with ketamine before testing to see whether it made them more or less likely to identify a false rubber hand as their own.

One student who took part in the study said that the experience was disturbing and scary.

"After they increased the dose I began to hallucinate," she said. "It made me feel scared. It felt like the bed was floating up and I felt very disorientated. I couldn’t find my way to the bathroom. It was quite disturbing. I needed the money at the time and I wouldn’t do it again."

John Mitchell, a spokesman for Rehab Guide, said the experiment is immoral.

“This is encouraging people to use ketamine for monetary reward," he said. "It’s a very dangerous game."

The study by Professor Paul Fletcher and Hannah Morgan, a Ph.D student, is titled “Exploring the Impact of Ketamine on the Experience of Illusory Body Ownership.”

The research was submitted in March to Biological Psychiatry, the official journal of the Society of Biological Psychiatry, and will be printed in the January 2011 edition. 

Click here to read more from the Cambridge News.