Anxiety disorders are the most common psychological disorder in America, according to the U.S. Surgeon General. There are various types of anxiety disorders, including panic disorder, obsessive-compulsive disorder (OCD), generalized anxiety disorder (GAD), specific phobia and post-traumatic stress disorder (PTSD). Many factors interact to cause the emergence of an anxiety disorder. One of those factors is abnormal levels of chemical messengers of the brain, called neurotransmitters.
Serotonin
Anxiety disorders are associated with decreased activity of the neurotransmitter serotonin (5-HT). Serotonin works to inhibit stress responses, the U.S. Surgeon General says. In cases of anxiety, doctors often prescribe drugs that increase the effectiveness or amount of serotonin. In particular, selective serotonin reuptake inhibitors (SSRIs), such as fluxotine (Prozac), paroxetine (Paxil) and citalopram (Celexa), are often used. SSRIs seem to work better than benzodiazepines for OCD and PTSD in particular, says the Surgeon General.
Gamma-Aminobutyric Acid (GABA)
Like serotonin, gamma-aminobutyric acid (GABA) is an inhibitory, calming neurotransmitter. Also like serotonin, GABA tends to be deficient in cases of anxiety disorders. To remedy the situation, benzodiazepines, such as lorazepam (Ativan) and alprazolam (Xanax), are frequently prescribed. According to the Surgeon General, benzodiazepines work by binding to GABA receptors and increasing the inhibitory response that GABA typically provides. The result is quick and safe relief from anxiety, although drug dependence can occur.
Norepinephrine
Abnormal activity of noreprinephrine, also known as noradrenaline, may also play a role in anxiety disorders. Norepinephrine is an excitatory neurotransmitter and also a stress hormone. It helps to keep us alert and to prepare for threats, says Consumer Reports. One class of drugs that works on norepinephrine is serotonin and norepinephrine reuptake inhibitors (SNRIs), such as duloxetine (Cymbalta) and venlafaxine (Effexor). Although SNRIs are FDA-approved to treat depression, they may be used for anxiety or other disorders, reports the Mayo Clinic. Side effects of SNRIs include dry mouth, insomnia, nausea and tremor.
Corticotropin-Releasing Hormone (CRH)
Abnormal functioning of corticotropin-releasing hormone (CRH) may also play a part in anxiety disorders, reports the Surgeon General. Like norepinephrine, CRH acts as both a stress hormone and a neurotransmitter. In an article published in the "European Journal of Pharmacology" in 2008, Florian Holsboer and Marcus Ising reported that CRH seems to be secreted at an increased level in cases of anxiety disorders. They state that drugs that target CRH receptors may be a promising future treatment for anxiety disorders and depression.
