Lab Chimps: Antidepressants Change Their Outlook

Former lab chimps on antidepressants can regain their spirits and learn to play again even after more than 20 years as test animals, according to a study presented at the American Association for the Advancement of Science meeting recently in Boston. Dr. Godelieve Kranendonk, one of the lead researchers, spoke extensively to Pallab Ghosh of BBC News about the findings.

Working with the AAP, a rescue center in the Netherlands for retired lab animals, Dr. Kranendonk discovered that many of the older chimpanzees were at first unable to overcome their history of trauma. After consulting with Martin Bruene, a German professor of human psychiatric disorders, she gave the chimps prescribed doses of SSRIs: Selective Serotonin Reuptake Inhibitors. Two popular examples of drugs in that category include Paxil and Zoloft.

The chimps in Kranendonk’s study suffered from severe trauma as a result of their work as lab animals, acting out by screaming, vomiting, or even worse. As the BBC reports, two of the experimental chimps “would spend a third of their waking hours eating their own vomit.” Ghosh visited the AAP sanctuary and was impressed to report that the animals are now calm and even friendly, with a former screamer coming forward to show the reporter his carrots. But it wasn’t just a lucky guess when it came to prescribing the lab chimps the antidepressant treatment.

In 2011, Dr. Kranendonk participated in an earlier study with several other researchers which detailed symptoms of depression and post-traumatic stress disorder in former lab chimps. In one case, the patient was a 36-year-old chimp who was taken from the wild as an infant, suffering multiple traumas since her own infants were also taken from her. In several cases, the chimps displayed severe symptoms that would, if seen in a human, be diagnosed as evidence of a mental illness that could respond to treatment with SSRIs.

As Tara Dodrill reported earlier this year, the federal government is retiring most of the research chimps in the United States. The retired chimps will have a home at the Chimp Haven, the de facto National Chimpanzee Sanctuary.

A safe home may be only part of the solution for severely traumatized lab chimps. Antidepressants may help give them a boost toward recovery when nothing else has worked.