Anxiety disorders affect around 18 percent of American adults in a given year, according to the National Institute of Mental Health. The neurotransmitters gamma-aminobutyric acid, serotonin and norepinephrine are all thought to be involved in the development of anxiety disorders. Manipulation of these interrelated neurotransmitter systems with medications is frequently used to treat anxiety disorders.
Medical researchers believe problems with the GABA neurotransmitter system in the brain are related to anxiety disorders. Brain receptors for GABA are the targets for medications used to relieve short-term anxiety symptoms, the benzodiazepines. Some commonly prescribed benzodiazepines include diazepam (Valium), alprazolam (Xanax), clonazepam (Klonopin) and lorazepam (Ativan). These drugs enhance the calming effect that GABA has in the brain. With the anxiety condition known as panic disorder, the panic attacks may be caused by interference with GABA receptor function.
Serotonin is also thought to be important in anxiety, especially the panic disorder type. Some evidence for this is that the drug buspirone -- which works to help reduce anxiety by enhancing serotonin activity in the brain -- binds to certain serotonin receptors. Normal serotonin activity appears to be important in maintaining feelings of well-being, and deficiencies in serotonin may be related to the development of anxiety disorders.
The serotonin-specific reuptake inhibitor drugs are often recommended as first-line treatment of anxiety disorders and SSRIs have been found to be effective for many people. These medications increase the serotonin available to brain cells. Specific SSRIs commonly used to treat anxiety disorders include fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft) and escitalopram (Lexapro).
Norepinephrine is a close cousin to epinephrine, also known as adrenalin. The "fight or flight" reaction to stress is associated with elevated adrenalin levels, and the stress-related sense of being in a state of fear is similar to anxiety, and especially to panic. Norepinephine function is thought to be involved in the symptoms of anxiety that are similar to those in stress, fear and panic.
Serotonin-norepinephrine reuptake inhibitor drugs work on both the serotonin and the norepinephrine neurotransmitter systems, and are also commonly used as first-line treatment for anxiety disorders. Examples of SNRIs medications include duloxetine (Cymbalta) and venlafaxine (Effexor).
Dopamine, epinephrine, acetylcholine and histamine are other neurotransmitters may also be involved in anxiety disorders. More research is needed to learn exactly how these and potentially other neurotransmitters are related to the causes and effective treatment of the symptoms of anxiety disorders.