Etiology of Anxiety Disorders
The etiology of anxiety disorders is not exactly known.
Genetic factors were found to play a role.
Nongenetic factors, such as various stressful life events during early or later stages of ontogenesis were thought to be even more important.
Several different neurotransmitter systems have been implicated in these disorders, including the noradrenergic, GABA, and serotoninergic systems in some parts of the brain.
The role of CO2 in the etiology of panic disorder is seriously discussed.