What Is Anxiety?
Anxiety disorders are a group of mental disorders that include generalized anxiety disorder, panic disorder, phobias, and social anxiety disorder. These conditions are estimated to affect 264 million people worldwide.
Humans experiencing anxiety disorders often describe both emotional symptoms—such as feelings of apprehension, dread, tension, restlessness, and irritability—and physical symptoms, such as rapid heartbeat, sweating, tremors, headaches, fatigue, insomnia, and gastrointestinal issues. Many factors determine why people suffer from anxiety, including past experiences, ongoing stressful events, and brain chemistry.
Why Animal Models of Anxiety Don’t Benefit Anxiety Research
Experimenters often use mice and rats in crude attempts to study human anxiety disorders. Examples of tests used on mice and rats include the open field test, the light/dark box test, and the elevated plus maze or elevated zero maze. These tests measure essentially the same thing: whether an animal would rather approach or avoid physical spaces that the experimenter thinks may scare them, such as the center of an open arena (as opposed to the walls or corners), a well-lit enclosure (as opposed to a dark enclosure), or unwalled platforms that are high off the ground.
In reality, all laboratory life is scary. Not only are animals subjected to invasive and stressful procedures, standard laboratory housing also does not meet their basic needs and causes them to be “CRAMPED (cold, rotund, abnormal, male-biased, poorly surviving, enclosed and distressed).” This is horrible for the animals and makes any data collected from experiments on them even more unreliable.
Some anxiety tests are more severe. In the Vogel conflict test, mice or rats are deprived of water or food. Then, they’re punished by electrical shocks when they try to get water or food presented to them. Experimenters think that if an animal makes fewer attempts to get the water or food after being shocked, this shows that they’re more anxious. This interpretation completely ignores the reality that shocks themselves can be anxiety-producing and that many other factors, such as learning and the state of deprivation in which the animals are kept, can affect the results of the test.
Experimenters also purposely attempt to induce anxiety in animals. They expose mice and rats to predators like cats, either through the scent of their urine or by enticing cats to lick food off an enclosure containing terrified mice or rats.
Overall, experiments on animals have been cited as the primary source of drug failure in human neurobehavioral trials. A key reason for this is that even though animals feel many of the same emotions we do, their brains are fundamentally different in ways that are critically important in biomedical and molecular research. For example, the brain cells that communicate with each other—and the brain cells that respond to drugs meant to treat anxiety, depression, and bipolar disorder—are drastically different between mice and humans.
In 2016, a Portuguese company developed a drug intended to help with anxiety, mood, and motor problems related to neurodegenerative disease. The drug was given to volunteers as part of the phase I clinical trial conducted by a French drug evaluation company. Six men, ages 28 to 49, experienced such adverse reactions that they had to be hospitalized. One participant was pronounced brain-dead and later died. A report on this incident reveals that “[n]o ill effects were noted in the animals, despite doses 400 times stronger than those given to the human volunteers.”
Anxiety Research Without Using Animals
Funds should be allocated to more relevant, human-based experimental models, such as advanced neuroimaging, the use of human cells for sophisticated in vitro research, and computer and mathematical modeling. For example, as part of the Human Connectome Project, researchers from a number of esteemed institutions recently used a variety of magnetic resonance imaging (MRI) techniques along with comprehensive psychological assessments of patients to map human brain circuits with symptoms of anxiety and depression, information that can be used to inform future clinical trials.
Critically, funds must also be shifted away from animal experiments and toward providing patients with greater access to mental health care and to detecting and preventing life events that contribute to the development of anxiety disorders.
For accurate diagnosis of anxiety disorders, suicidality, depression, alcohol addiction, or other mental illnesses, it’s necessary to call and/or be seen by qualified healthcare professionals. For those in the U.S., if you’re in crisis or you think you may have an emergency, call your doctor or 911 immediately. If you’re feeling suicidal, thinking about hurting yourself, or concerned that someone you know may be in danger of hurting themselves, call the National Suicide Prevention Lifeline at 1-800-273-TALK (1-800-273-8255). It’s available 24 hours a day, seven days a week and staffed by certified crisis response professionals. If you’re located outside the U.S., call your local emergency line immediately.