- Maya Kummrow, a doctor of veterinary medicine, writes in a paper recently published in the Journal of Zoo and Wildlife Medicine that non-human primates have been used as models of human psychopathology — the study of mental illness — for decades. But, she notes, “the acquired knowledge has only hesitantly been applied to primates themselves.”
- In the paper, Kummrow states that she is seeking to raise awareness among her fellow veterinarians about the wealth of information on NHP psychopathology that is available in human medicine and anthropology literature and calls for “mental health assessments and professionally structured treatment approaches” in NHP medicine, as well.
- In this Q&A, Mongabay spoke with Kummrow about how her review of the literature on NHP psychopathology and treatment might apply to primate conservation efforts.
Though it is a highly controversial practice due to the many ethical concerns it raises, the use of nonhuman primates (NHPs), mostly monkeys, as research subjects has led to advances in human health that have “saved or improved millions of human lives,” according to a 2017 white paper.
Just 0.5 percent of the animals currently used in medical research are NHPs, the paper states, but they’ve led to some important breakthroughs, not just in treating human diseases but also in “our knowledge of how the human brain works and its role in cognitive, motor, and mental illnesses such as Alzheimer’s, Parkinson’s, and depression.”
However, humans have rarely used the findings derived from primate research to benefit the species that have helped us achieve these valuable insights. For instance, Maya Kummrow, a doctor of veterinary medicine and an assistant professor at the Clinic for Zoo Animals, Exotic Pets, and Wildlife at the University of Zurich in Switzerland, writes in a paper recently published in the Journal of Zoo and Wildlife Medicine that NHPs have also been used as models of human psychopathology — the study of mental illness — for decades. But, she notes, “the acquired knowledge has only hesitantly been applied to primates themselves.”
In the paper, Kummrow states that she is seeking to raise awareness among her fellow veterinarians about the wealth of information on NHP psychopathology that is available in human medicine and anthropology literature and calls for “mental health assessments and professionally structured treatment approaches” in NHP medicine, as well.
“Our article is not about new findings but a review of existing knowledge and compilation of already published literature,” Kummrow told Mongabay. “The application of this knowledge to primate medicine has long been dismissed as anthropomorphic.”
Some 62 percent of the more than 700 known primate species are currently facing serious threats to their survival in the wild. Many conservationists view the keeping of primates in zoos as critically important for their preservation. And there are numerous stories of orphaned primates like chimps and orangutans being kept in sanctuaries and rehabilitation facilities — and as human developments like mines and oil palm plantations continue to push ever deeper into their habitat, similar stories are likely to continue to emerge. Primates are also sometimes rescued from wildlife traffickers and in need of rehabilitation before they can be released back into the wild. So it certainly makes sense for us to try and better understand how to treat primates that are under human care.
Mongabay spoke with Kummrow about how her review of the literature on NHP psychopathology and treatment might apply to primate conservation efforts. “I think the important thing is to consider each specimen as an individual with a life history and series of positive and adverse events,” she said. “As this individual’s ‘backpack of life experiences’ cannot be undone, the best approach to psychological stability is certainly to avoid accumulations of adverse events.”
Read the full conversation below.
Note: This interview has been edited for readability and flow.
Mongabay: In your own words, what are your main findings about causes and pathogenesis of abnormal behavior in non-human primates, and why are they significant?
Maya Kummrow: Our article does not provide new findings in primate medicine but is meant to raise awareness that a) psychological health must be considered in animal medicine as much as we do this in human medicine and b) causes and pathogeneses of psychopathologies are similar (but not identical) in primates and humans. Any adverse event may be a cause for psychopathologies, the question is always what qualifies for an adverse effect and this is where species-specific and individual factors come into play and anthropomorphism must be avoided. The biopsychosocial continuity and a high degree of social and emotional cross-species homology between human and non-human primates, however, justifies a certain extrapolation of knowledge from human psychology to non-human primates, therefore any events that would be considered psychologically traumatic to a human being may also be traumatic to a non-human primate.
Some of the more common events we encounter with primates in captivity are maternal separation (handraising), social isolation, social entrapment (incompatibility with social environment and inability to escape), and boredom. That’s not to say that the free-ranging situation doesn’t provide any traumatic situations (poaching, dislocation, predator pressure, etc.) but those are more difficult to capture and document and therefore their impact on the behavior of the individual remain even more obscure.
As for the pathogenesis, I think it is most important to understand that traumatic events don’t immediately translate in a certain abnormal behavior but they render an individual susceptible to psychopathologies which will become more or less apparent through abnormal behaviors in response to trigger situations. Trigger situations may be, but don’t have to be, identical with the previously experienced traumatic incidents and abnormal behaviors (the “symptoms”) are not uniformly representing psychopathologies. Therefore, symptomatically treating the behavior downstream, e.g. stereotypical behavior, will not solve the problem as it is merely an expression of an underlying inability to cope with the situation. Avoiding the triggering situation for the stereotypic behavior may also only temporarily or partially help since there may be various situations triggering the behavior. Only the comprehensive understanding of the individual’s life history and potentially traumatic events will elucidate the etiologic background of observed inadequate responses to challenging situations and help to approach the problem at the roots.
Mongabay: What implications do your research have for the conservation of these species? What should conservationists and/or policymakers take away from your study?
MK: We don’t know a lot about psychopathologies and their impact on survival or fitness in free-ranging primate species. But rehabilitation in captivity is an integral part of conservation projects and presumably many of those primates have gone through traumatizing situations.
I think the important thing is to consider each specimen as an individual with a life history and series of positive and adverse events. As this individual’s “backpack of life experiences” cannot be undone, the best approach to psychological stability is certainly to avoid accumulations of adverse events. And although the perception of adversity is individual, certain events, such as maternal separation or social deprivation, have been scientifically proven to render non-human primates susceptible to psychological disorders and should be avoided. However, adverse events are never completely avoidable in life and the ability to cope with situations is part of mental stability and can be trained, which eventually is part of the psychological treatment.
For reintroduction processes, for example, it is important to understand the impact of an individual’s life experiences, to assess its susceptibility to psychopathologies in response to trigger situations, individually introduce them to potential trigger situations, and support the learning process to cope. Insofar, standard operating protocols are certainly helpful and important but they have to be tailored to an individual’s need and what has worked for a previous case may not be adequate for the next, even if the symptomatic behavior (such as stereotypies, automutilation) is the same.
Also, expectation for treatment goals have to be individually adjusted: treatment can lead to the ability to live and cope with the burden of a high susceptibility to develop psychopathologies, but some individuals may always be prone to fall back or develop different abnormal behaviors and may remain lifelong patients. Rather than expecting a return to full recovery, less detrimental alternative coping behaviors may have to be accepted to replace the initial abnormal behavior.
Mongabay: You write that your review of the literature “aims to raise awareness among the veterinary community of the wealth of literature on NHP psychopathologies…” Why is it necessary to build awareness of these things in the veterinary community?
MK: I myself had to learn the hard way: I was treating a silverback gorilla with chronic diarrhea and wasting and once he had lost almost half of his body weight despite literally every diagnostic measure and medical therapy approach I could think of, I eventually sat down and observed the patient in the group. Very quickly I discovered significant abnormalities in the social structure and consulted with a psychiatrist (the co-author on the manuscript) and we evaluated the problem interdisciplinarily, combining veterinary medicine, primatology, and psychiatry. A two-year story cut short: after several thousand dollars spent on diagnostics and medicine, we removed a single animal from the group and the silverback started gaining weight within a few weeks. There are pathogenetic explanations for stress-induced enteritis but I would have never thought it could have such an impact.
It is only in the last few years that behavioral studies and therapies have become established in veterinary medicine but that was primarily for domestic animals, such as dogs, cats and horses. For zoo animals and free-ranging wildlife, however, I see two main reasons for the hesitation to include psychological health and [why] many colleagues would rather go with the straight classical veterinary medicine approach.
Firstly, the husbandry and management of wild animals is burdened with the claim to keep animals “wild” despite captivity. Whether we like it or not, though, we need to acknowledge the impact of our presence and behavior on the animals and realize that despite naturalistic enclosure, the animals will never be “wild”. Purposeful human influence on the behavior of the animals is the subject of controversial discussions, oftentimes not only evolving around the animal’s welfare and health but relating to broader ethical, philosophical, and political topics, which often complicates or even hinders a veterinarian’s work.
The second reason is the hesitation to acknowledge that psychopathologies are nothing else but an “organ-failure,” a malfunction of the brain, and have little to do with “nutcases.” It can, however, not be measured with simple blood tests, as a liver-failure can, and the diagnostic techniques are not standard teaching material in veterinary medicine but require a comprehensive evaluation of biology and physiology, research into life-history, and observational studies of the individual. The interpretations are subjective and not as clear cut as blood tests with reference values, which veterinarians are trained to work with. “Sit, observe, and interpret” may not be considered as “hard fact science” and is prone to political and professional controversies when it comes to the interpretations and therapy decisions. However, in some cases, medical therapy just doesn’t do the entire trick, as I learned in the silverback gorilla case: plainly treating the diarrhea (which eventually turned out to be more of a symptom than the primary disease) without addressing his social stress situation plainly didn’t help the patient.
Mongabay: Are your findings specifically meant to inform the vets who work in wildlife rehabilitation programs, or are they aimed at vets in general?
It was important for us to place this manuscript in the Journal of Zoo and Wildlife medicine, the prime publishing organ for zoo practitioners worldwide. We wanted to reach primarily veterinarians working with non-human primates, however, the principles of causes, pathogeneses, and treatment approaches for abnormal behaviors holds true for any species, regardless of taxonomy. A reptile species is likely to react differently to maternal neglect than a primate or elephant but that does not mean that reptiles are not also prone to develop psychopathologies (e.g. stereotypies) upon certain adverse conditions.
Mongabay: In your paper, you call “for the necessity to include mental health assessments and professionally structured treatment approaches in NHP medicine.” Can you elaborate on why that’s important?
I often see the tendency of veterinarians to treat the symptoms and ask for a drug or treatment against e.g. automutilation or stereotypic behavior in a specimen. This is treatment without diagnosis and is a shot in the dark, prone to failure. A thorough diagnosis consists of a comprehensive evaluation of the life history and ideally 24-hour remote observations (e.g. video taping). In particular with primates, which oftentimes bond with their care staff and closely interact if not manipulate, biased and subjective misinterpretations of behavioral abnormalities are oftentimes quickly misunderstood as solid diagnoses and result in ineffective therapy measures. To avoid subjective and anthropomorphic interpretations, a structured assessment is important. Most veterinarians are not trained to plan, perform, and evaluate such a psychological assessment and this is where interdisciplinary approaches show great potential. Animal trainers or behavioral specialists, human psychiatrists, animal care staff, biologists and veterinarians should work together to create a diagnostic procedure as unbiased and objective as possible, plan for further interventions and reevaluate the outcome (and possibly start all over again in case of failure).
• Friedman, H., Ator, N., Haigwood, N., Newsome, W., Allan, J. S., Golos, T. G., … & Bianchi, P. (2017). THE CRITICAL ROLE OF NONHUMAN PRIMATES IN MEDICAL RESEARCH. Pathogens & immunity, 2(3), 352. doi:10.20411/pai.v2i3.186
• Kummrow, M. S. & Brüne, M. (2018). PSYCHOPATHOLOGIES IN CAPTIVE NONHUMAN PRIMATES AND APPROACHES TO DIAGNOSIS AND TREATMENT. Journal of Zoo and Wildlife Medicine, 49(2), 259-271. doi:10.1638/2017-0137.1
Follow Mike Gaworecki on Twitter: @mikeg2001
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