"Still, I think when you look into their eyes, there is something coming back. I had the impression that they have a personality, and there was something behind their look." -Martin Brüne Image: Flickr/AfrikaForce
As our closest relatives, chimpanzees have played a role in science for nearly 80 years. Because they can contract infections such as HIV and hepatitis, they have proved valuable for biomedical research. This research has revealed another trait, however, that chimpanzees share with humans: vulnerability to psychological damage. Concerned by mounting evidence of lasting trauma in great apes, the European Union banned their use in research in 2010. And in January 2013, a National Institutes of Health report recommended that all but 50 of the nearly 700 chimps in NIH-supported labs be retired to sanctuaries. In 2010 the Scientific American Board of Editors published an editorial calling for a ban on the use of apes in invasive biomedical research.
Martin Brüne has seen this damage firsthand. A psychiatrist at the University Hospital in Bochum, Germany, Brüne specializes in detecting early signs of psychosis in humans. His interest also extends to psychological similarities among chimps and humans. His research took an unusual turn seven years ago when a primatologist in Austria asked him to observe a group of veteran laboratory chimps. Brüne noticed behaviors among them akin to depression, anxiety disorders and post-traumatic stress disorder, although he and his colleagues still wrestle with whether to apply these clinical terms to nonhumans. Three years later, he decided to begin working with a group of 10 former research chimpanzees in a sanctuary called AAP in the Netherlands, led by biologist Godelieve Kranendonk. The chimps received antidepressants as part of their treatment regimen.
Brüne shared early results of this treatment at the annual meeting of the American Association for the Advancement of Science, held in Boston in February. Afterward, Scientific American caught up with him to hear about his work with his extraordinary patients.
What was your impression when you first saw the chimps in the sanctuary?
Even as a non-primatologist, I immediately could recognize that their behaviors were really grossly abnormal. Some of the animals engaged in self-mutilating behaviors such as scratching wounds and keeping them open, and others showed stereotypic movements like constant body rocking. Others smeared their feces everywhere and engaged in coprophagy [eating their feces]. Such behaviors have never been observed in wild populations, so we can be quite sure to assume that these are abnormal behaviors.
Where had those chimps been before?
Most of the chimps were at a facility for biomedical research in the Netherlands, and many of them are infected with HIV and hepatitis virus. You can retire them in the sanctuary, but you cannot integrate them in other groups, because of the infections.
Did you approach the apes as a psychiatrist in the same way you would humans?
Well…no, I wouldn’t say that. They are behind a fence, and it’s dangerous to come too close. You can’t predict their behavior. Still, I think when you look into their eyes, there is something coming back. I had the impression that they have a personality, and there was something behind their look.
Can you trace certain behaviors to certain conditions in the lab?
There are a couple of more common causes of the behavioral abnormalities, such as social deprivation, stressful experiences like regular darting to anesthetize the animals, and so forth. For some of them, there is probably early separation from mothers and peers. But it’s very hard to tell, because the individual history of many animals is not known in its entirety.