DER SPIEGEL article - English translation

06/06/2005

Monkeys in the sights

Apes can also suffer from depression, phobias or anxiety. Therefore, doctors demand to treat zoo animals psychiatrically if necessary.

When Harry Prosen met him, Brian was a bundle of nerves. Without ceasing, he ran in circles and clapped his hands. After almost after every meal, the bonobo vomited. Upon approach by other bonobos, Brian screamed in panic, biting himself or the other animal bloody.

The Milwaukee County Zoo in Wisconsin, USA, had taken over the eight-year-old chimpanzee from a research lab where he had lived in a tiny cage with his dominant father. In vain, nurses and veterinarians tried to reassure Brian. Then they finally sought advice from Prosen, the head of local psychiatric department.

He was very reminiscent of his human patients. Therefore, he prescribed the monkey not only sedatives and antidepressants, but also behavioral therapy. This was the beginning of a new life for Brian: The animal slowly gained confidence by becoming accustomed to toys and other bonobos in small steps. In addition, the doctor - based on the model of human psychiatry - prescribed a strictly structured daily routine. The keepers always fed Brian at the same time and in the same place; they always praised him with exactly the same words.

Brian was Prosen's first non-human patient. Meanwhile, the 74-year-old psychiatrist has treated more than 50 great apes. Especially when it comes to chimpanzees or bonobos, his advice is in demand worldwide. He himself also hopes to gain insights into mentally ill people: "If we know when our closest relatives have mental problems, then we will also better understand why we become mentally ill."

Not only in Wisconsin, also in Germany, psychiatrists are targeting monkeys. In the magazine "Science", Bochum's physicians call for psychiatric treatment. "In research laboratories, circuses and some zoos, apes often have symptoms similar to those of mentally ill people, so they have the same right to therapy," says Martin Brüne from the Westphalian Center for Psychiatry in Bochum. Typical mental disorders are depression, phobias or so-called stereotypes.

For example, some animals bob their bodies for hours, a behavior that can even lead to self-mutilation: The monkeys then tear hair out or scratch and bite themselves. Other isolated animals eat their dung or smear it against the glass. Some people also suffer from a kind of bulimia: They choke up their food and then swallow it down again. "A dangerous disorder," says primate researcher Signe Preuschoft. "Chemical burns in the esophagus and periodontal disease may arise."

For three years now, the German has been managing a rehabilitation project for more than 40 former laboratory chimpanzees at the Tierpark Gänserndorf in Austria. Gradually, the primatologist prepares the traumatized monkeys for life in the group. The therapist is satisfied with her results so far: "Most monkeys have now learned what it means to be a chimpanzee."

Together with the Bochum psychiatrist Brüne, the primatologist now wants to develop guidelines for the treatment of behavior-obsessed apes. "We have known the consequences of social isolation for years, but we still do not know exactly when and how to treat the animals," says Preuschoft. Also missing is any classification for the mental illnesses of apes: "The classification based on symptoms, such as suicidal thoughts, means the diagnostic key for people can not be easily transferred."

But not all primatologists share their view that monkeys experience human-like sensations. Eberhard Fuchs, head of the Division of Clinical Neurobiology at the German Primate Center Göttingen, warns against anthropomorphism - all too easily people tend to attribute human characteristics to animals. "If a monkey looks sad to us, that does not have to mean that he is sad."

In fact, it is uncertain if the behavioral problems so common in captivity exist in the wild. "Normally, apes, despite their high sensitivity, seldom suffer from emotional problems," says Jane Goodall, who has been observing wild chimpanzees in Tanzania for more than 40 years.

At least once, after all, she has also experienced that one of her charges fell into a depression-like state: After his mother died, the eight-year-old chimpanzee Flint became increasingly lethargic and refused food. The monkey mourned for three weeks before he died - at the exact spot where his mother's body had lain.

By Diane Renz