Stress and Anxiety Disorders

Much of the research relating to animal models of anxiety has been devoted to developing more effective drugs for the treatment of the various anxiety disorders. Using selective breeding of laboratory mice and rats, investigators have developed high-anxiety and low-anxiety lines that have been especially valuable for basic research purposes. Other approaches to enhance the expression of an anxiety-like phenotype have included prenatal or early postnatal exposure to stressors, maternal immune activation, or selecting offspring based upon differences in the maternal behaviors of their mothers. In addition, risk genes for anxiety disorders have been studied in animal models, including genes related to serotonin, neuropeptide Y, neuropeptide S, and corticotropin-releasing factor signaling in the brain. Finally, some infant rhesus monkeys display an anxious temperament and extreme behavioral inhibition when separated from their mothers. This nonhuman primate model affords many opportunities to explore brain mechanisms and interventions that may be effective in preventing the further development of an anxious phenotype as these monkeys mature.