Chamomile (Matricaria recutita) May Provide Antidepressant Activity in Anxious, Depressed Humans: An Exploratory Study

Context: Anxiety and depression are the most commonly reported psychiatric conditions and frequently occur as comorbid disorders. While the advent of conventional drug therapies has simplified treatment, a large segment of the population goes untreated or declines conventional therapy for financial, cultural, or personal reasons. Therefore, the identification of inexpensive and effective alternative therapies for anxiety and depression is of relevance to public health.

Objective: The current study explores data from a 2009 clinical chamomile trial in humans to determine if chamomile provides clinically meaningful antidepressant activity versus a placebo.

Design: In the 2009 randomized, double-blind, placebo-controlled study, the research team examined the antianxiety and antidepressant action of oral chamomile (Matricaria recutita) extract in participants with symptoms of comorbid anxiety and depression.

Setting: In the 2009 study, all of participants' evaluations took place at the Depression Research Unit at the University of Pennsylvania. The study drew participants from patients at the Department of Family Medicine and Community Health's primary care clinic at the University of Pennsylvania, Philadelphia.

Participants: Of the 57 participants in the 2009 trial, 19 had anxiety with comorbid depression; 16 had anxiety with a past history of depression; and 22 had anxiety with no current or past depression.

Intervention: The intervention and placebo groups in the 2009 trial received identically appearing 220-mg capsules containing either pharmaceutical-grade chamomile
extract standardized to a content of 1.2% apigenin or a placebo (ie, lactose monohydrate NF), respectively.

Outcome Measures: In the current study, the research team used generalized estimating equations analysis to identify clinically meaningful changes over time in scores from the Hamilton Depression Rating (HAM-D) questionnaire among treatment groups.

Results: In the current study, the research team observed a significantly greater reduction over time in total HAM-D scores for chamomile vs placebo in all participants (P< .05). The team also observed a clinically meaningful but nonsignificant trend for a greater reduction in total HAM-D scores for chamomile vs placebo in participants with current comorbid depression (P = .O62). When the team examined the HAM-D core mood item scores, it observed a significantly greater reduction over time for chamomile vs placebo in all participants (P < .05) and a clinically meaningful but nonsignificant trend for a greater reduction over time for chamomile vs placebo in participants without current or past depression (P= .06).

Conclusion: Chamomile may provide clinically meaningful antidepressant activity that occurs in addition to its previously observed anxiolytic activity.

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