To date, the biological explanations for many types of anxiety disorders remain inadequate.
Studies have implicated a dysregulation of specific neurotransmitters such as serotonin, dopamine and gamma-aminobutyric acid (GABA) as potential causes for both depression and anxiety disorders. These hypotheses are based on the results of pharmacological treatments, but there are no definitive clinical trials that demonstrate the dysregulation of these neurotransmitters as causative factors of anxiety, potentially explaining why the treatment of anxiety with antidepressants is often ineffective.
- Most research indicates that anxiety disorders are complex and arise from intricate neurochemical, neuroanatomic, neuroinflammatory, genetic, neuroendocrinologic and psychoimmunologic factors.
- Cognitive-behavioral factors also play a role in anxiety disorders.
- Genetic predisposition contributes to anxiety disorders. Family aggregated and twin studies support the role of genetic influence and heritability of various anxiety disorders, such as OCD.
- Environmental factors and stress issues also contribute to anxiety disorders, particularly acute stress or PTSD which are associated with an overwhelming traumatic or life-threatening situation or exposure.