Pilot study results guide changes to anxiety research

March 12, 2015

Over the last year, University of Wisconsin–Madison research into the biological underpinnings of anxiety has drawn a great deal of interest — largely due to the researcher’s plan to incorporate infant monkeys raised apart from their mothers.

Results from a pilot study have led Ned Kalin, psychiatry professor and lead investigator, to a change that plan. This important study, which hopes to point out new directions for developing better treatments for mental health disorders that cause serious suffering for millions of people, will move forward at UW–Madison without separating young monkeys from their mothers.

In the pilot study, outlined last year in a report to the National Institutes of Health (NIH), researchers observed the behavior of 25 monkeys that were rejected by their mothers and raised out of necessity by human caregivers alongside other young monkeys. The researchers expected monkeys that were reared without their mothers to be more prone to anxious behavior, but the pilot study found the monkeys that were reared with their peers at UW–Madison to be less anxious than monkeys raised by their mothers.

Based on this data, the study design has been changed. Researchers will now examine the wide range of individual differences in the development of anxiety in monkeys raised by their mothers. While this study will not examine the effects of early adversity, it will characterize the developmental trajectories of alterations in brain systems underlying anxiety disorders in young monkeys. This approach will allow researchers to identify the brain mechanisms occurring early in life that lead to the vulnerability to develop anxiety and depression.

Basic science is an exploration of the unknown, but researchers are guided by new knowledge revealed by careful study. The complexity of natural systems and organs like the brain still far outstrip our knowledge. Therefore, animal studies remain important in cases in which new discoveries have the potential to help people in dire circumstances.

Mental illness, which affects one in four people — including children — is particularly troubling. In addition to creating immeasurable disability and suffering, the worst outcome, suicide, is increasing and already among the leading causes of death in adolescents. In order to develop treatments that will be more effective and allow millions of people to live without disabling psychiatric problems, it is necessary to understand the root cause of psychiatric illnesses. The decision to use animal models to understand human psychiatric disorders is not made lightly, and is weighed against the potential for reducing human suffering.

NIH has approved the study design change supported by the preliminary data, and the approvals granted in UW–Madison’s review process allow the study to proceed in accordance with federal laws and regulations.

“We continue to stand with Dr. Kalin as he conducts this important work,” says Marsha Mailick, UW–Madison vice chancellor for research and graduate education. “It is scientifically significant, ethically conducted, and is a promising avenue for developing new treatment strategies for the millions of people with painful mental disorders related to anxiety. Without research like this, we won’t develop the knowledge we need to help anyone suffering from these kinds of debilitating conditions.”