"Extremely cruel" monkey experiments aimed at simulating human depression have been blasted by animal rights campaigners.
Macaques were restrained in tiny cages and randomly electro-shocked in solitary isolation for 90 days by Chinese researchers.
The primates were also placed under strobe lights, constant light or darkness, drenched in ice-water, starved and dehydrated, the study by the School of Traditional Chinese Medicine, Southern Medical University, said.
Sarah Kite, spokeswoman for Action for Primates, said: "Monkeys are deliberately being subjected to extremely cruel and barbaric treatment in an attempt to simulate human depression.
"The researchers are trying to induce depressive-like behaviours, such as a huddle posture, self-clasping with head at or below the shoulders and self-scratching and anxiety-like behaviours, such as self-clasping and body quivering.
"There is no doubt the monkeys suffered substantially in this research.
"Not only is this treatment of monkeys extremely cruel, no amount of artificial and cruel stressors inflicted on them can compare with the complex emotional, genetic and environmental stressors that cause mental illness and depression in humans.
"To achieve this, researchers are subjecting monkeys to a disturbing litany of abuse involving social isolation, restraint stress and chronic unpredictable stressors."
Thieving monkeys can spot expensive items and will steal phones instead of empty bags
Citing from the paper, Ms Kite said the monkeys were probably killed after being placed in cages so small they could barely turn; suffering "inescapable electric shocks to their feet"; being sprayed with ice-water and subjected to a deafening buzzer at 100db for 12 hours.
The researchers said they used a total of 15 macaques aged six to seven in the experiments, explaining the species was chosen as it was "vulnerable to depression".
Hungry monkeys break into family homes to steal food as pandemic stops tourist trade
Their study, which is yet to be peer-published, claimed: "Depression is a serious mental illness, which is one of the main causes of disability at present.
"The cause and location of depression are still unclear. The purpose of this study is to establish a stable and reliable model of non-human primate depression, and further confirm the significance of neuritis (painful nerve damage) in the pathogenesis (development of) of depression by combining in vivo and in vitro (live and test tube) experiments. "
Cheeky monkeys caught having sex on car bonnet during family trip to safari park
It added humans and macaques, or cynomolgus monkeys, shared 92.83% of their genes, and continued: "We simulated the environment of human depression and established a cynomolgus monkeys depression model by pro-depressive prodedure (PDP).
"Here we found that a 12-week exposure to PDP can effectively induce the depressive behaviors of cynomolgus monkeys.
"PDP increases the time of depressive-like and anxious-like behaviors and decreases locomotor and exploratory behaviors, which were maintained after a 4-week recovery period."
T he researchers have been approached for comment.
Source: Read Full Article