Psychiatric Disorders in Lab Chimpanzees Mirror Those in Human Trauma Survivors, New Study Finds

The Physicians Committee
NEWS RELEASE June 22, 2011
Psychiatric Disorders in Lab Chimpanzees Mirror Those in Human Trauma Survivors, New Study Finds
Findings Draw Attention to Ethical Imperative to End Chimpanzee Experiments; Study's Author Urges Passage of Great Ape Protection and Cost Savings Act
Hope Ferdowsian, M.D., M.P.H.

WASHINGTON—Chimpanzees used in invasive experiments show symptoms of depression, anxiety, and compulsive behaviors similar to mood and anxiety disorders seen in traumatized humans, a new study shows. The findings, published June 16 in PLoS ONE, the Public Library of Science’s peer-reviewed journal, raise new ethical concerns about harmful experiments on chimpanzees. Study lead author Hope Ferdowsian, M.D., M.P.H., with the Physicians Committee for Responsible Medicine (PCRM) is urging Congress to consider these findings as it weighs the Great Ape Protection and Cost Savings Act. Watch Dr. Ferdowsian present Mood and Anxiety Disorders in Chimpanzees >

“Chimpanzees clearly have the capacity to suffer mental and physical anguish, much as humans do,” says Dr. Ferdowsian, a practicing physician and director of research policy at PCRM. “We now know that a chimpanzee's mind and emotional well-being are affected by experimentation in ways that parallel the psychological trauma experienced by victims of torture and other forms of abuse. This makes it critically important for the United States to join the long list of countries that have ended invasive experiments on chimpanzees.”

In the paper “Signs of Mood and Anxiety Disorders in Chimpanzees,” which Dr. Ferdowsian co-authored with PCRM senior research scientist Debra Durham, Ph.D., among other colleagues, researchers collected data in two phases. In phase 1, the authors reviewed case reports of traumatized chimpanzees and developed alternative criteria to evaluate chimpanzee behavior, which correspond to criteria used to diagnose humans with psychiatric disorders. In phase 2, researchers used the same measures to evaluate behaviors of both wild chimpanzees and chimpanzees previously used in laboratory experiments and currently living in sanctuaries.

The findings indicate that chimpanzees used in experiments display symptoms comparable to post-traumatic stress disorder and major depression. These patterns of behavior are extremely rare in wild populations of great apes and signal the presence of disordered rather than adaptive behaviors.

Dr. Ferdowsian has evaluated and treated human survivors of trauma, including torture, who can suffer from a range of psychiatric disorders. She is also an assistant clinical professor in the Department of Medicine at the George Washington University Medical Center. Dr. Durham is a primate behavior expert.

Funding for this study was received from the Arcus Foundation.

For an advanced copy of the paper or an interview with Dr. Ferdowsian or Dr. Durham, please contact Tara Failey at 202-527-7319 or

Founded in 1985, the Physicians Committee for Responsible Medicine is a nonprofit health organization that promotes preventive medicine, conducts clinical research, and encourages higher standards for ethics and effectiveness in research.