St. John's Wort Extract and Seasonal Affective Disorders

St. John's Wort Extract and Seasonal Affective Disorders

Reference: Martinez B, Kasper S, Ruhrmann S, Moller HJ: Hypericum in the Treatment of Seasonal Affective Disorders. J Geriatr Psychiatry Neurol 7 (suppl 1): S29-S33, 1994.

Summary: In this randomized single-blind trial, twenty Seasonal Affective Disorder (SAD) patients, ranging in age from twenty-nine to sixty-three years of age, were divided into two groups after a one week washout period. Both groups received 3 x 300 mg of St. John's Wort extract LI 160 daily plus either phototherapy at 3,000 lux or less than 300 lux, two hours a day for four weeks. At the end of this experimental design, the authors note that there was a statistically significant reduction in the Hamilton Depression Scale (p < 0.001) score in both groups.

Comments/Opinions: Seasonal affective disorder (SAD) is a mood disorder which typically begins in the winter months and disappears in the spring. In contrast to endogenous depression, it is characterized by hypersomnia, fatigue, increased appetite, and carbohydrate craving. Eighty percent of the individuals afflicted with SAD are women.

The current treatment of choice for SAD patients is phototherapy at an intensity of 2,500 to 3,000 lux for two hours daily. Phototherapy works quite rapidly, with reversal of some SAD symptomatology occurring within two to five days of the start of treatment.

Despite phototherapy's success, its physiological mechanism of action remains unclear. For example, studies have concluded that in contrast to controls, norepinephrine, serotonin, and dopamine levels do not differ in SAD patients receiving phototherapy.(1) However daytime melatonin levels are elevated in SAD patients and will decline, along with symptoms of carbohydrate craving and hyperphagia, when given phototherapy.(2) This suggests that melatonin may play a key role in SAD rather than the biogenic amines as previously noted. Whether or not St. John's Wort extract influences melatonin is an interesting question that seems to be quite worthwhile investigating in the light of the conclusions of the current study.

Research by Drs. Martinez, Kasper, Ruhrmann, and Moller from the Psychiatric University Clinic in Bonn, Germany, concludes that St. John's Wort extract LI 160 is effective for those suffering from SAD and may represent an alternative form of treatment to phototherapy. They boldly point out "...that the antidepressant effect of St. John's Wort extract may be potentiated by the additional application of phototherapy." However, despite this optimism, the authors note that their conclusions require more substantiation due to their small sample size and lack of a control group. It is hoped that future studies will address these shortcomings, and expand upon the therapeutic relationship between SAD and St. John's Wort extract.

(1) Rudorfer MW et al: Biogenic amines in seasonal affective disorder: effect of light therapy. Psychiatric Res 46(1): 19-28, 1993.

(2) Danilenko KV, Putilov AA et al: Diurnal and seasonal variation of melatonin and serotonin in women with seasonal affective disorder. Arctic Med Res 53(3): 137-45, 1994.

Natural Product Research Consultants, Inc.


By R. Reichert

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