In the first part of this series, we discussed anxiety and specifically generalized anxiety disorder (GAD) as a diagnosis. Now we are going to look at the research associated with the treatment of GAD and let the research inform our decision making about what works when a person presents with GAD. Some of these findings may surprise you.
SSRIs
Although the effect size of SSRIs in GAD is small, 0.33 they remain the recommended first line option for treatment. It’s also important to confirm that someone has had an adequate trial of SSRI treatment before assuming it’s not effective. The choice of which SSRI will depend on the side effect profile and other patient factors such as presence of insomnia, substance use, or pregnancy. Escitalopram is a good place to start, fluoxetine, or sertraline can be alternative options. Although paroxetine has the FDA approval for GAD it has more side effects like weight gain and sedation, along with several other factors that make this medication a poor first-line option. If the first medication trial is ineffective it’s reasonable to try a second SSRI or switch to the SNRI duloxetine.
When SSRIs Don’t Work
The next step in many cases is to try a medication from a different class. Two SNRIs have been well studied in GAD, venlafaxine, and duloxetine. Venlafaxine is not considered a first line choice due to the side effect profile and the small increase in efficacy. From the meta-analysis on anxiety treatments the effect size is 0.36 slightly better than the SSRIs but it would likely be undetectable clinically. Duloxetine is slightly better with respect to side effects and can be a good choice if you chose to use an SNRI for anxiety treatment. It has the added benefit of lower risk for sexual side effects compared to venlafaxine and possibly improved cognition.
Bupropion in Anxiety Disorders
There is some evidence for the use of bupropion in GAD. In one study small study of 25 participants bupropion beat the SSRI escitalopram head-to-head. Other lines of evidence include more improvement in GAD when bupropion was added as a combination treatment with SSRIs compared to adding buspirone. For clarification the effect size of buspirone in GAD is 0.17 which would be unlikely to produce any observable clinical improvement in anxiety symptoms. I largely stay away from buspirone unless it’s used to treat sexual side effects of SSRIs. Bupropion may be good option for patients who do not want the side effect profile of an SSRI. Although we lack the large RCTs for bupropion in GAD there is some evidence to support its use. The negative studies indicating bupropion worsened symptoms of anxiety come from studies in panic disorder where bupropion was found to worsen panic symptoms.
What About New Antidepressants?
Vortioxetine had a lot of hype when it first came out, and many believed it would work for GAD. Unfortunately, like many medications when we believe something should theoretically work based on the mechanism of action, we are sadly disappointed. This is one of those cases. The effect size was found to be 0.12 and it did not even cross into the small range. This medication performed worse than buspirone for GAD.
Vilazodone also had one positive study published for GAD. Again, based on the MOA it should work just fine, it has typical SSRI like effects in addition to 5-HT1A effects like buspirone, you should get the best of both worlds theoretically. This one positive study was followed by two distinctly negative studies and a calculated effect size of 0.26 which is considered small.
Both were not submitted for FDA approval for GAD based on the negative results.
The Hydroxyzine Argument
Hydroxyzine is an antihistamine that’s been out for a long time. As I stated earlier it has approval for tension associated with psychoneurosis which is the old psychanalytic way of describing anxiety. It’s often seen as ineffective, but the effect size was higher than SSRIs and SNRIs for the treatment of GAD. Hydroxyzine had an effect size of 0.45, and we may want to reconsider the use of this medication. Some limitations are the size of the studies and duration of the studies, but this still provides a fair amount of evidence that hydroxyzine may perform better than we think.
Quetiapine Surprised Me
Quetiapine is an antipsychotic medication usually not considered as a treatment option for anxiety disorders. However, the effect size was large with a range from 1.0 to 2.2. To put this in perspective this medication outperformed SSRIs, SNRIs, and benzodiazepines. Why did it not gain FDA approval? If you watched my other videos, you should know that the side effect profile is difficult to tolerate. Metabolic side effects and sedation are common, and the FDA does not view anxiety disorders as significant enough to warrant this degree of risk. One place where this medication may be very useful is in bipolar disorder with severe anxiety. We avoid antidepressants in this population at all costs, quetiapine offers a good option with strong evidence and strong antidepressant effects in bipolar depression.
Where this fits in clinical practice for me is as a 3rd or 4th line option after all other avenues have been explored except for bipolar disorder as stated above. The antipsychotic medications have been known to have a positive effect on anxiety, but the limitation remains side effects.
Anxiety as a less Severe Form of Psychiatric Illness
According to the FDA medications like aripiprazole and quetiapine are reasonable adjunctive therapies for patients with major depression that does not respond to first line treatment options. This is not their view for anxiety disorders that respond poorly to first line options. When we look at disability caused by depression and anxiety there isn’t much difference in the odds of being disabled for depression vs anxiety (3.5 Vs 3.1). For whatever reason we continue to view anxiety as less significant although DSM does not identify a clear diagnostic hierarchy.
Things like psychotherapy are often recommended as first line options. In the 1980’s when GAD was first conceived, it was thought to be a mild disorder where psychotherapy is the most effective treatment. In fact, psychotherapy did well it had an effect size of 0.5 which is nearly the same as benzodiazepines. Psychotherapy is a good place to start for anyone presenting with an anxiety disorder. I’m also a big believer of combining psychotherapy and medication for anxiety disorders.
What about Benzos?
Benzodiazepines can have all sorts of effects on the body. Largely we think of the benefits of benzodiazepines in anxiety disorders as having a major effect on the physical symptoms of anxiety and not so much on the chronic worry that characterizes the disorder. Many of the effects of benzodiazepines would not be measured by traditional anxiety rating scales based on the updated conception of GAD. Nevertheless, Benzodiazepines had an effect size of 0.4-0.5 which falls into the moderate range for GAD.
A final Option to Consider
Silexan the proprietary extract of Lavender oil has good evidence and a large effect size when used to treat GAD. In Germany there is a respect for the power of natural products, and they are regulated and prescribed in the same manner as pharmaceutical drugs. When silexan was studied in GAD the effect size can range from 0.5 to 0.9. This is a large effect size and I have another video that covers Silexan in detail if you are interested. This can be added to most medication regimens without significant drug interactions and has even been shown to decrease the use of benzodiazepines in those who are using them for GAD. It can be purchased under the brand Name Calm Aid for around $30 per month, and if you are wondering I get no financial compensation for saying this I’m just presenting the evidence.
Conclusion
We covered a lot here today and I think one of the most important points to stress is the importance of finding the underlying cause of anxiety symptoms. I believe anxiety is driven by other underlying factors as discussed at the beginning of the video. There are many reasons to be anxious and all require a different approach. Without this clarification the patient is likely to continue struggling. Another important point is theoretical mechanism of action that should work, do not always work as seen in the case of vilazodone. We also had some surprises, hydroxyzine, and silexan performed very well but traditional first line options such as SSRI and SNRIs were not so great. I hope this discussion was helpful and if you want more content on anxiety disorders, let me know below in the comments section.
