Health for life

A world-first completed clinical study by an Australian team has found Kava, a medicinal South Pacific plant, significantly reduced the symptoms of people suffering anxiety.

The study, led by the University of Melbourne and published in the Journal of Clinical Psychopharmacology, revealed Kava could be an alternative treatment to pharmaceutical products for the hundreds of thousands of Australians who suffer from Generalised Anxiety Disorders (GAD)

Lead researcher, Dr Jerome Sarris from Department of Psychiatry at the University of Melbourne, said GAD is a complex condition that significantly affected people’s day-today lives. Existing medications have a modest clinical effect and new effective options were needed for patients with anxiety.

“Based on previous work we have recognised that plant based medicines may be a viable treatment for patients with chronic anxiety. In this study weve been able to show that Kava offers a potential natural alternative for the treatment of chronic clinical anxiety. Unlike some other options it has less risk of dependency and less potential for side effects,” he said.

The study also found that people’s genetic differences (polymorphisms) of certain neurobiological mechanisms called GABA transporters, may modify their response to Kava.
“If this finding is replicated, it may pave the way for simple genetic tests to determine which people may be likely to have a beneficial anxiety-reducing effect from taking Kava,” Dr Sarris said.

During the eight-week study, 75 patients with clinically diagnosed Generalised Anxiety Disorder were given Kava or placebo, and anxiety levels were regularly assessed.
Results showed a significant reduction in anxiety for the Kava group compared to the placebo group at the end of the study.

In participants diagnosed with moderate to severe GAD, Kava had an even greater effect in reducing anxiety. Following the completion of the controlled phase, 26 per cent of the Kava group were classified as in remission from their symptoms compared to six per cent of the placebo group.

Participants in the Kava group were given tablets twice per day consisting of water-soluble extracted Kava (peeled rootstock) for a total dose of 120mg of kavalactones for the first three-week controlled phase. In cases of non-response this was increased to a double-dose twice per day for the second three-week controlled phase. Participants in the placebo group took matching dummy tablets in the same manner.

Kava was also well tolerated. Results showed no significant differences across the two groups for liver function which had previously been a concern for Kava’s medicinal use. In addition there were no considerable adverse reactions that could be attributed to Kava and no difference in withdrawal or addiction between the groups.

An additional novel finding of the study, recently published in Phytotherapy Research was that Kava increased women’s sex drive compared to those in the placebo group, believed to be due to the reduction of anxiety, rather than any aphrodisiac effect.

Future studies confirming the genetic relationship to therapeutic response, and any libido-improving effects from Kava is now required. Dr Sarris said these significant findings are of importance to sufferers of anxiety and to the South Pacific region which relies on Kava as a major export.

The study was funded by the NHMRC and Integria Healthcare who manufacture MediHerb and Thompson’s Kava products.

Exercise may benefit people suffering from depression, according to an updated systematic review published in The Cochrane Library. The authors of the review found evidence to suggest that exercise reduces symptoms of depression, although they say more high quality trials are needed.

Worldwide, more than 120 million people suffer from depression. Antidepressants and psychological therapies are recommended as effective treatments for depression. However, antidepressants have side-effects and some people per not to receive, or may not have access to, psychological therapies. Physical exercise is also used as a treatment for depression. There are a number of reasons why it might work such as changing hormone levels that affect mood or providing a distraction from negative thoughts.

The previous version of the Cochrane review found only limited evidence of benefit for exercise in depression. However, more trials have now been completed, leading researchers to carry out a further update. Altogether, they reviewed the results of 39 trials involving 2,326 people diagnosed with depression. The severity of patients symptoms was assessed using standard scales of depression.

In 35 trials comparing exercise with control treatments or no treatment, the researchers saw moderate benefits of exercise for treating depression. Exercise was as effective as psychological therapy or taking antidepressants, although these findings were based on only a few, small, low quality trials.

"Our review suggested that exercise might have a moderate effect on depression," said one of the authors of the review, Gillian Mead of the Centre for Clinical Brain Sciences at the University of Edinburgh in Edinburgh, UK. "We cant tell from currently available evidence which kinds of exercise regimes are most effective or whether the benefits continue after a patient stops their exercise programme."

Conducting high quality trials involving exercise can be problematic. For example, it is difficult to conceal which patients have been allocated to treatment groups, and which have been allocated to control or no treatment groups. Theore, the researchers carried out a separate analysis focussing on the high quality trials. In these six trials, the effect of exercise was weaker.

"When we looked only at those trials that we considered to be high quality, the effect of exercise on depression was small and not statistically significant," said Mead. "The evidence base would be strengthened by further large-scale, high quality studies."