作者：Caroline Cassels
出處：WebMD醫學新聞
August 22, 2008 — 新研究發現，補充維他命B群比起安慰劑並不能減少憂鬱或憂鬱症狀發生率。
一項隨機分派、雙盲、安慰組控制的臨床試驗，共收納299位年紀較大的男性，服用維他命B12、B6及葉酸長達2年的時間，在情緒上沒有明顯的變化。
作者寫到，我們採取3種方法調查維他命與憂鬱之間的關係，貝克憂鬱量表[BDI]分數的改變、臨床上憂鬱症狀的發生率及憂鬱的緩解，不論何種方式，在24個月當中都未看出維他命B群比安慰劑好。
本篇文章的第一作者是澳洲柏斯南大城市衛生機構的內外科醫學士Andrew H. Ford，研究發表在8月號的臨床精神學期刊。
先前的研究指出，體內較低濃度的維他命B與葉酸會導致憂鬱，然而，許多研究是觀察性報告或是受試者有服用抗憂鬱劑等干擾因素。
【前瞻性設計】
目前這項研究的目的在於前瞻性地決定長時間給予維他命B群是否能減緩75歲以上老年人發生憂鬱症狀的時間。
為了進行研究，研究者們隨機收納一個大型研究中做腹主動脈瘤篩檢的299名病患。
所有的受試者都有高血壓、或其他病史而接受治療，BDI分數高於18分以上，以及迷你精神狀態測驗分數低於24分有明顯認知障礙者都被排除；除此之外，已經接受維他命B群治療的病患也被排除，試驗期間由2001年6月至2004年6月。
受試者隨機服用一顆含400-μg維他命B12、2-mg葉酸及25-mg維他命B6的膠囊或一顆安慰劑，研究員告知受試者這兩年間每天早上要服用一顆膠囊。
受試者與研究員都不知道是吃藥或吃安慰劑直至試驗完成。
研究的主要試驗終點是在這期間BDI分數的改變，研究員同時檢驗原本沒有憂鬱臨床症狀，但後來卻有憂鬱的比例。
此試驗有149人在安慰組，150人在治療組，退出試驗的比例為19.4%，因此最後的分析是241個有完成兩年試驗的受試者。
【輔助治療的角色？】
此試驗顯示，接受治療組有24%的病患仍然沒有憂鬱症狀，但與安慰劑組沒有明顯差異。
有23名受試者，其中12人在治療組，11人在安慰劑組發生中至重度憂鬱症，在經過24個月的試驗期間無明顯差異。
研究員還發現，治療組受試者體內維他命B12及葉酸濃度增加，且半胱胺酸濃度降低。他們也發現不論發生憂鬱或未發生憂鬱，受試者體內維他命濃度是相似的，這個發現證明低維他命B濃度、高半胱胺酸濃度與憂鬱的關聯性並不強。
他們寫道，維他命的補充，對於嚴重憂鬱症是否為有效的輔助療法，以及女性是否會比男性來得有效仍待保留態度。
作者表示沒有利益衝突。
B Vitamins, Folic Acid Do Not Reduce Depression Incidence, Severity
By Caroline Cassels
Medscape Medical News
August 22, 2008 — Supplementation with B vitamins appears to be no better than placebo in reducing the incidence of depression or depressive symptoms, new research suggests.
A randomized, double-blind, placebo-controlled trial of 299 older men showed treatment with vitamins B12, B6, and folic acid produced no significant change in mood over 2 years.
"We investigated the association between vitamin use and depression in 3 different ways, none of which showed an advantage of B vitamins compared with placebo over 24 months: change in Beck Depression Index [BDI] scores, incidence of clinically significant depressive symptoms, and remission of depression," the authors write.
With first author Andrew H. Ford, MBBS, from South Metropolitan Health Service, in Perth, Australia, the study is published in the August issue of the Journal of Clinical Psychiatry.
Previous research has linked lower concentrations of B vitamins and folate to depression. However, many of these reports have been observational and or confounded by the fact that participants were on antidepressants.
Prospective Design
The purpose of the current study was to prospectively determine whether treatment with B vitamins over an extended period of time reduced the onset of clinically depressive symptoms in a cohort of men aged 75 years and older.
For the study, investigators recruited a random sample of 299 subjects who were participants in a large population-based study of abdominal aortic aneurysm screening.
All subjects were being treated for or had a history of hypertension. Individuals were excluded from the study if they had a BDI score of 18 or higher and significant cognitive impairment, as determined by a Mini-Mental State Examination score of less than 24. In addition, individuals who were already taking B vitamins were excluded from the study, which was conducted from June 2001 to June 2004.
Participants were randomized to receive a single oral capsule containing 400-μg B12, 2-mg folic acid, and 25-mg B6 or an identical-looking placebo capsule. Study subjects were told to consume 1 capsule every morning for 2 years.
Study subjects and investigators were blinded to group membership until the last follow-up assessment was completed.
The study's primary outcome was changes in BDI scores over the study period. The researchers also examined the proportion of individuals who were free of clinically significant depressive symptoms at baseline but became depressed during the trial.
A total of 149 and 150 subjects were in the placebo and active-treatment groups, respectively. With a 19.4% dropout rate, the final analysis was based on the 241 who completed the 2-year trial.
Role as Adjunctive Therapy?
The study revealed that participants in the active-treatment group were 24% more likely to remain free of depression during the trial, but the difference between the groups was not significant.
Among 23 men — 12 in the vitamin group and 11 in the placebo cohort — who had mild to moderate depression, there was no difference between the 2 groups after 24 months of treatment.
Investigators also found that participants in the active-treatment group had increased blood levels of B12 and folate and reduced levels of plasma homocysteine. They also found that these blood levels were similar in men with and without depression, a finding that suggests the potential link between low vitamin B levels, high homocysteine, and depression is not strong.
"It remains to be determined whether vitamin supplementation would be an effective adjunctive antidepressant treatment for people with severe depression, and if women would benefit more than men from this therapeutic approach," they write.
The authors report no conflicts of interest.
J Clin Psychiatry. 2008;69:203-1209.
[ 本帖最後由 goodcat1111 於 2008-9-2 22:58 編輯 ] |
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