Anti-Anxiety Medications Explained

What you need to know about the medications used to treat anxiety.

Posted Nov 25, 2011

Americans' use of anti-anxiety medications has increased dramatically, and while medications can play an important role in the treatment of anxiety disorders, they are not risk-free and in some cases may exacerbate a problem. Nonetheless, because anti-anxiety medications work quickly and involve less effort than psychotherapy, they are a popular choice of treatment among both doctors and patients. This may be particularly true in the primary-care setting, where anxiety disorders are frequently treated.

First, a word about therapy. Cognitive Behavioral Therapy has been shown to be as effective as medications for anxiety disorders and is considered to be first-line treatment for these conditions. The advantage of psychotherapy over medications is that the benefits tend to persist beyond the end of treatment. The reason for this is easy to see: Recovery achieved in therapy occurs via learning, and when you have learned that something isn't dangerous you don't fear it anymore. Conversely, when anxiety is treated by using a medication, the recovery often depends on the continued use of that medication. Often, the best results are achieved when therapy and medications are combined.

Types of Anti-Anxiety Medications

Not all anti-anxiety medications are the same, and it is important to make a distinction between the different classes used to treat anxiety. The risks and benefits associated with each medication class can vary dramatically. Further, certain medications often used for anxiety may actually decrease the efficacy of psychotherapy being administered at the same time.

The following are the main classes of medications typically used to treat anxiety and their associated risks and benefits, along with some examples of specific medications in each class.

Selective Serotonin Reuptake Inhibitors (SSRIs). SSRIs are one of the most commonly used types of medication for anxiety and are often a psychiatrist's first choice for this purpose. SSRIs have been proven to be very effective for anxiety, are non-addictive, don't cause memory impairment or interfere with psychotherapy, and have minimal side effects. When SSRIs do cause side effects, they usually subside within the first week.  A notable exception, however, is decreased sexual sensation, which occurs in a significant minority of patients.

Some additional disadvantages of SSRIs are that that they take 4-to-6 weeks to reach maximum efficacy and certain SSRIs can cause uncomfortable withdrawal symptoms if stopped abruptly. For individuals with bipolar disorder, SSRIs may trigger a manic episode; for this reason, they are given to these patients with a mood stabilizer. There is also some evidence that SSRIs may increase the risk of suicide among younger patients.

SSRIs work by increasing the amount of signaling between neurons that use a chemical called serotonin to communicate with each other. They are also used to treat depression. Currently available SSRIs include Prozac (fluoxetine), Celexa (citalopram), Lexapro (escitalopram), Zoloft (sertraline), Paxil (paroxetine), and Luvox (fluvoxamine).

Serotonin Norepinephrine Reuptake Inhibitors (SNRIs). SNRIs do the same thing that SSRIs do but they also increase the amount of signaling between neurons that use a chemical called norepinephrine to communicate with one another. When used to treat anxiety, the benefits and side effects of SNRIs are essentially the same as those for SSRIs. Like the SSRI, the SNRIs take 4-to-6 weeks to reach maximum effect. The three currently available SNRIs are Effexor (venlafaxine), Cymbalta (duloxetine), and Pristiq (desvenlafaxine).

Benzodiazepines. This class of medication includes the well-known drugs Valium (diazepam), Xanax (alprazolam), Klonopin (clonazepam), and Ativan (lorazepam). Although benzodiazepines are prescribed frequently for anxiety, particularly by non-psychiatrists, they are no longer considered to be a first-line treatment for these conditions. They reduce anxiety quickly; however, they can cause problems when taken long-term and should be used with caution.

Benzodiazepines cause tolerance, which means that over time more of the drug needs to be taken to achieve the same effect. There is also a withdrawal syndrome associated with these medications which in the extreme can cause seizures and even death. Further, certain individuals may develop an addiction to these medications. Benzodiazepines also inhibit the formation of new memories which can have a negative impact on psychotherapy. And these medications can be lethal when combined with alcohol or opioids and are involved in a significant percentage of fatal overdoses.

Nonetheless, when used appropriately, benzodiazepines can play an important role in the treatment of an anxiety disorder. For example, they are sometimes used in combination with an SSRI for the first few weeks of treatment before the SSRI reaches maximum efficacy. Long-term treatment with a benzodiazepine may be appropriate for some individuals with anxiety but is not considered to be first-line treatment and should only be used in this way under the care of a psychiatrist.

Buspirone. Buspar (buspirone) is a medication sometimes used to treat anxiety. Like SSRIs, buspirone works by influencing the neurons which use serotonin to communicate, but unlike SSRIs, which increase the amount of serotonin available to all serotonin receptors, buspirone affects only one specific subtype of serotonin receptor. An advantage of this selectivity is that buspirone does not cause the sexual side effects sometimes associated with SSRIs. Like SSRIs and SNRIs, buspirone may take 4-to-6 weeks to reach maximum efficacy.

Hydroxyzine. Vistaril (hydroxyzine) is sometimes used to treat anxiety. Like benzodiazepines, hydroxyzine's effects occur quickly. Unlike benzodiazepines, hydroxyzine is non-habit forming and does not cause tolerance, withdrawal, or memory impairment. The most significant side effect of hydroxyzine is sedation, but this tends to decrease over time. The anti-anxiety effects of hydroxyzine are thought to be due to its blocking of the histamine receptor; however, hydroxyzine appears to be more effective for anxiety than other antihistamines (such as Benadryl); this may be due to its interaction with a subset of serotonin receptors.

Gabapentin. Neurontin (gabapentin) is primarily used to treat seizures and nerve pain but is also used with some frequency by psychiatrists to treat anxiety. Like hydroxyzine, gabapentin works quickly and without many of the problems associated with benzodiazepines. However, there may be a withdrawal syndrome associated with gabapentin and some patients experience significant drowsiness. Like SSRIs, gabapentin may also be associated with an increased risk of suicide.

Because gabapentin has "gaba" in its name, it is often mistakenly believed to directly affect neurons that use a chemical called GABA to communicate with one another (which is how benzodiazepines work). The exact mechanism by which gabapentin achieves its effects is unknown but may involve binding to a cellular structure that moves calcium across the cell membrane.

This is not a complete list of the medications used to treat anxiety, and a psychiatrist may opt to use something else depending on the specific circumstances. Further, some medications listed above do not have an FDA indication for anxiety disorder but are included here because they are frequently used off-label for this purpose. Given the large number of medications that are used for anxiety and their sometimes serious side effects, it is important that these medications be used only under the care of a physician. Further, the long-term efficacy and minimal side effects of cognitive behavioral therapy make it an excellent treatment for anxiety disorders and it should always be a consideration regardless of whether medications are used.