ABSTRACT
The biological mechanisms, including genetics, related to stress, fear and anxiety are identified. The hypothalamic and sympathetic nervous system responses, and cortisol as the stress hormone, are all discussed. General adaptation syndrome is explained. The pathophysiology of anxiety-related disorders, including general anxiety disorder, panic attacks, post-traumatic stress disorder, obsessive-compulsive disorder and social anxiety disorder are all discussed. Stress and child abuse are highlighted. The biology of fear is discussed. Anxiety personality disorders (avoidant personality disorder, dependent personality, histrionic personality, narcissistic personality and borderline personality) and the pharmacology of the anxiolytic drugs are highlighted.
