Herbs for anxiety – the possibilities are endless!

This is a short research summary on passionflower and chamomile that I originally wrote for my University’s newsletter.

(TLDR? Chamomile and passionflower have both been studied with positive results for acute and generalized anxiety.)

Herbs for anxiety – the possibilities are endless! 

Anxiety is one of the most common mental disorders in the United States. An estimated 31% of U.S. adults experience an anxiety disorder at some point in their lives (Harvard Medical School, 2007), and that does not take into account anxiety not categorized as a “disorder,” such as temporary or situational anxiety or PMS-related anxiety. Antidepressants are a common class of pharmaceutical drugs used to treat anxiety (ADAA, 2016), and their use has increased 65% from 1999 to 2014 (Pratt et al., 2017). Unfortunately, antidepressants can have side effects as severe as suicide, but more common effects include sexual dysfunction, weight gain, and sleep interference (Ferguson, 2001). Due to the range of side effects, the discontinuation rate is as high as 70% for some antidepressant medications (Ferguson, 2001). Benzodiazepines, another common class of drugs used to treat anxiety, are often sedating and can have dependence issues over the long term (ADAA, 2016). Fortunately, herbs can offer a safer alternative to pharmaceuticals with similar, if not greater effectiveness (Sarris, 2018; Savage et al., 2017).  Recent studies on chamomile (Matricaria recutita) and passionflower (Passiflora incarnata) offer compelling evidence for use of herbs in two different anxiety-related contexts.  

Mao et al. (2016) conducted a Randomized Controlled Trial (RCT) to assess the impact of a chamomile extract on people who were diagnosed with moderate to severe Generalized Anxiety Disorder (GAD). Ninety-three study participants took 1500 mg (500 mg three times/day) of chamomile extract for 12 weeks. Participants who had a reduction in their anxiety measurements over the initial 12 weeks were then were randomly assigned to continue taking the chamomile or a placebo for an additional 26 weeks (continuation therapy), for a total study duration of 38 weeks. The researcher’s primary outcome measure was the time to relapse during continuation therapy, which was evaluated by measuring anxiety scores at regular intervals. While the chamomile group had less relapses than the placebo group, the difference was not statistically significant.  However, secondary outcomes measures related to symptoms of GAD demonstrated that people taking chamomile had a statistically significant reduction in anxiety symptoms and overall better psychological wellbeing compared to placebo.  

The chamomile group also had an added bonus of significant reductions in body weight and blood pressure. In addition to these positive findings, this research is also notable because the 38-week duration of the study is much longer than most herb/anxiety studies, which usually range from 4 to 12 weeks (Sarris, 2018). Longer studies are more clinically useful to confirm safety and evaluate ongoing impact on health. Finally, this study is unique because human studies on chamomile are rare. This same group of researchers completed the only other RCT in 2009 (Amsterdam et al., 2009, as cited in Mao et al., 2016). Taken as a whole, this research offers support for herbalism’s traditional use of chamomile as a calming agent.

Like chamomile, passionflower is another herb with a long history of use by traditional herbalists to calm and ease tension. Several studies have demonstrated its usefulness in GAD compared to placebo and pharmaceuticals (Sarris, 2018), and a recent study by Dantas et al. (2017) has demonstrated benefit on par with the pharmaceutical midazolam when used in the dentist’s office – a common site of situational anxiety. The RCT conducted by Dantas et al. assessed 40 dental surgery patients who took either 260 mg passionflower extract or 15 mg midazolam 30 minutes before the surgery. Anxiety was measured through subjective questionnaires and physical measurements of heart rate, blood pressure, and oxygen saturation. Results showed that there were no significant differences in measures of anxiety for the herb group vs. the pharmaceutical group, except that 20% of people taking midazolam reported amnesia, whereas the passionflower did not have this effect.

These two studies represent recent research, but they are just the tip of the iceberg. Herbs with positive research showing anti-anxiety effects include bacopa (Bacopa monniera), gotu kola (Centella asiatica), lemon balm (Melissa officinalis), kava (Piper methysticum), skullcap (Scutellaria laterifolia), ginko (Ginkgo biloba), rhodiola (Rhodiola rosea) and ashwagandha (Withania somnifera) (Sarris, 2018). 

Needless to say, these herbs provide the herbalist with a lot of “tools in the toolbox,” and the herbalist-client consultation also offers benefit. Herbalists typically spend more time with their clients than a typical medical doctor visit, allowing the person to tell their health story while the herbalist gets a more complete picture of the client’s health. This allows the herbalist to create an herbal formula and dosing regimen that is customized to the individual – something that is not typical in conventional medicine. When an herbalist’s knowledge and skills are combined with recent scientific research, herbal medicine emerges as a powerful tool for support. 

References¹

1. References:

Anxiety and Depression Association of America. (2016). Medication. Retrieved from https://adaa.org/finding-help/treatment/medication.

Dantas, L.-P., de Oliveira-Ribeiro, A., de Almeida-Souza, L.-M., & Groppo, F.-C. (2017). Effects of passiflora incarnata and midazolam for control of anxiety in patients undergoing dental extraction. Medicina Oral, Patologia Oral Y Cirugia Bucal, 22(1), e95–e101.

Harvard Medical School. (2007). National Comorbidity Survey (NCS). (Retrieved from https://www.hcp.med.harvard.edu/ncs/index.php.

Ferguson, J. M. (2001). SSRI Antidepressant Medications: Adverse Effects and Tolerability. Primary Care Companion to The Journal of Clinical Psychiatry, 3(1), 22–27.

Mao, J. J., Xie, S. X., Keefe, J. R., Soeller, I., Li, Q. S., & Amsterdam, J. D. (2016). Long-term chamomile (Matricaria chamomilla L.) treatment for generalized anxiety disorder: A randomized clinical trial. Phytomedicine: International Journal of Phytotherapy and Phytopharmacology, 23(14), 1735–1742. https://doi.org/10.1016/j.phymed.2016.10.012

Pratt, L.A., Brody, D.J., & Gu, Q. (2017). Antidepressant Use Among Persons Aged 12 and Over: United States, 2011–2014. NCHS Data Brief, 283. Retrieved from https://www.cdc.gov/nchs/data/databriefs/db283.pdf

Sarris, J. (2018). Herbal medicines in the treatment of psychiatric disorders: 10-year updated review. Phytotherapy Research: PTR. https://doi.org/10.1002/ptr.6055

Savage, K., Firth, J., Stough, C., & Sarris, J. (2018). GABA-modulating phytomedicines for anxiety: A systematic review of preclinical and clinical evidence. Phytotherapy Research: PTR, 32(1), 3–18. https://doi.org/10.1002/ptr.5940