Written by Tatjana Djakovic, Staff Writer. Passion flower extract reduced symptoms of anxiety by 68% (equal to treatment by oxazepam a leading pharmaceutical) but with less side effects.

Generalized anxiety disorder is the most common anxiety disorder that is twice as prevalent in women than in men and has no known cause. (1) Generalized anxiety disorder is defined by the presence generalized, persistent anxiety in addition to the following symptoms: worry, fear, restlessness, concentration difficulties and irritability, muscle aches, sweating, dizziness, accelerated heart rate. (2) Only, one-third of the individuals affected with anxiety seek treatment. (3)

The treatment for anxiety disorders includes a class of drugs known as benzodiazepines. There are several problems associated with the use of benzodiazepines, because about 25-30% of all patients fail to respond and develop tolerance, dependence and impaired alertness. In addition, discontinuing medication results in withdrawal syndrome which is associated with anxiety including: tremors, palpitation, and perceptual disturbances to light, sounds, touch or motion. (4)

Passionflower is an herbal supplement which has been used to treat sleep disorders, restlessness, nervous stress and anxiety. (5) In order to evaluate the efficacy of passionflower, a double-blind, randomized placebo parallel group study has compared the use of passionflower and a drug known as oxazepam.  The study consisted of 36 patients (20 women and 16 men) aged between 19 and 47 years that have been diagnosed with generalized anxiety disorder for a period of 6 months and longer.  The participants in group one were given 45 drops of passionflower extract plus placebo tablet, whereas those in group 2 received 30 mg of oxazepam plus placebo drop. Patients were assessed by a psychiatrist at beginning of study and at day 4, 7, 14, 21 and 28 days after the medication started.

The principal measure of the outcome was the HAM-A score (known as Hamilton Anxiety Rating Scale), which is a psychological questionnaire that is used to rate the severity of anxiety. It consists of 14 questions; each one is scored 0-4 points. If the total score of 0-17 is considered mild, 18-25 mild to moderate, 26-30 moderate to severe, and over 30 would indicate severe anxiety. (6)

There were no significant differences between the two groups at the beginning of the study. The difference in the two treatments was apparent in the time it took to initially decrease the symptoms. In the oxazepam group, the stress level decreased by approximately 31% (from 19 to 13 points as approximated using Hamilton anxiety score chart) in a period of 4 days, where as in the passionflower group it took 7 days for the stress to decrease by the same amount. After 4 days, there were no significant differences between the two groups (p<0.008) and in both groups, the anxiety decreased by approximately 68% (from 19 to 6 points) after 30 days in both groups.

A variety of side effects was also analyzed, and it was found that impairment of job performance was observed more often in the oxazepam group. (p=0.049)  The main finding of the study was that passionflower and oxazepam are effective in the treatment of generalized anxiety disorder. The oxazepam has a faster onset of action than passionflower, while the passionflower has a lower incidence of impairment of job performance. (7)

Source: Akhondzadeh, Shahin, et al. “Passionflower in the treatment of generalized anxiety: A pilot double‐blind randomized controlled trial with oxazepam.” Journal of clinical pharmacy and therapeutics 26.5 (2001): 363-367.

© 2001 Blackwell Science Ltd, Journal of Clinical Pharmacy and Therapeutics, 26, 363±367

Posted January 28,2013.

References:

  1. Rowa K, et al., and Martin A.,. “Generalized anxiety disorder.” Psychopathology: History, Diagnosis, and Empirical Foundations (2008): 78.
  2. Blazer DG, Hughes DC, George LK, et al. (1991) Generalized anxiety disorder. In: Bobus LN, Regier DA, eds. Psychiatric Disorders in America: the Epidemiological Catchments Area Study. New York: Fress Press, 180±203.
  3. Andrews, G., et al. “Why does the burden of disease persist? Relating the burden of anxiety and depression to effectiveness of treatment.” Bulletin of the world Health Organization 78.4 (2000): 446-454.
  4. Rickels K, Case WG, Downing RW. (1983) Long-term diazepam therapy and clinical outcome. JAMA, 250, 767±771.
  5. Krenn, Liselotte. “[Passion Flower (Passiflora incarnata L.)–a reliable herbal sedative].” (1946) 152.15-16 (2002): 404.
  6. Maier W, Buller R, Philipp M, Heuser I. The Hamilton Anxiety Scale: reliability, validity and sensitivity to change in anxiety and depressive disorders. J Affect Disord 1988;14(1):61–8.
  7. Akhondzadeh, Shahin, et al. “Passionflower in the treatment of generalized anxiety: A pilot double‐blind randomized controlled trial with oxazepam.” Journal of Clinical Pharmacy and Therapeutics 26.5 (2002): 363-367.