In this article, we discuss the “Putative Antidepressant Effect of Chamomile (Matricaria chamomilla L.) Oral Extract in Subjects with Comorbid Generalized Anxiety Disorder and Depression”
Plant name and species
Chamomile (Matricaria chamomilla L.)
Aim of study
The aim of this study was to investigate the antidepressant effects of chamomile extract in people with generalized anxiety disorder (GAD), with or without comorbid depression too.
Study method
It was a randomised double-blind placebo-controlled trial, in which 179 subjects received a capsule of chamomile extract daily for up to 8 weeks. Various models were used to assess people’s moods before and after treatment. The questionnaires included generalized anxiety disorder (GAD) rating (subjects were then categorised into those with and without comorbid depression), Hamilton rating scale for anxiety (HRSA), Beck anxiety inventory (BAI), Hamilton rating scale for depression (HRSD) and Beck depression inventory (BDI). Results were then collated and statistically analysed.
Herbal preparation
Each capsule contained 500mg of pharmaceutical-grade chamomile flower extract, which had been extracted using 70% ethanol and water. This was the equivalent of 2g of chamomile flowers, and corresponded to 6mg of flavonoids.
Sample size
179 subjects were given chamomile extract.
Results of study
Interestingly, there was no statistically significant difference in anxiety symptoms in groups during the 8 weeks of chamomile therapy. However, subjects with generalised anxiety disorder and comorbid depression demonstrated significant reductions over time for the HRSD depression scale and BDI scores versus people without comorbid depression.
Discussion
Chamomile’s mode of antidepressant action in humans is unknown, and there are various hypotheses on the mechanism of action. For example, a variety of molecules in chamomile have neurokinin-1 receptor (NK1r) antagonist activity which has anxiolytic and antidepressant effects.
Other molecules may also affect hypothalamic-pituitary-adrenocortical (HPA) axis activity that regulates mood and consequently symptoms of depression and anxiety.
Conclusion
In addition to its traditional use for anxiety, the oral extract of chamomile demonstrated a reduction in depression symptoms in patients with generalised anxiety disorder and comorbid depression.
