Animal Models in Anxiety Research

Fear and anxious apprehension are highly evolutionarily conserved responses triggered by a real or perceived imminent threat. These are adaptive responses, classically described as fight or flight responses, which comprise emotional, autonomic, and motor arousal. They are rapidly initiated and diminish as the danger abates. Anxiety states display physiological features that are similar to those evoked by fear, but as defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM) of the American Psychiatric Association, these behavioural disturbances persist beyond the appropriate period. Anxiety disorders are prevalent in all societies, and in 2014 they were the sixth leading cause of disability worldwide in terms of years lived with disability.