News Author: Karla Gale, MS
CME Author: Laurie Barclay, MD
Release Date: June 1, 2007; Valid for credit through June 1, 2008 Credits Available
Physicians - maximum of 0.25 AMA PRA Category 1 Credit ™ for physicians;
Family Physicians - up to 0.25 AAFP Prescribed credit for physicians
June 1, 2007 — Persistent smoking appears to be a predictor of depression symptoms, the results of a longitudinal study of Finnish twins suggest. On the other hand, investigators report in the May issue of Psychological Medicine, this association was not seen in individuals who stopped smoking many years ago.
"Although nicotine in cigarettes has some mood-elevating properties, in the long-run chronic exposure to cigarette smoke may have a more important role in the etiology of depressive symptoms," lead author Dr. Tellervo Korhonen told Reuters Health.
According to Dr. Korhonen, from the University of Helsinki, and her team, the underlying mechanism linking smoking and depression has not been identified. To investigate, the researchers used information from the Finnish Twin Cohort, a population-based database consisting of same-sex twin pairs born before 1958.
The current study was based on records from 10,977 men and women. Smoking status was determined by questionnaires conducted in 1975 and 1981. Twins who responded to at least one of the two earlier surveys were evaluated with the Beck Depression Inventory in 1990.
"The Beck Depression Inventory is a valid measure of screening depressive symptoms in a population-based study," Dr. Korhonen noted; it does not represent a clinical diagnosis. Her team defined a score > 9 as an indication of depressive symptoms.
The authors used multiple logistic regression analyses, in which never-smokers were used as the reference category. They found that men were significantly more prone to depressive symptoms if they had reported smoking at the time of both earlier surveys (OR 1.42), or were smokers in 1971 who had quit by 1981 (OR 1.68).
作者们采用多元回归分析的统计学方法，其中从不吸烟的人被作为参照类。他们发现男人中如果较前两次调查中均已报到吸烟者明显有抑郁症状（OR 1.42），1971年的吸烟于1981年时已戒烟者也是如此（OR 1.68）。
Among women, the only significant predictive factor after adjustment was smoking as of 1975 followed by smoking cessation by 1981 (OR 1.38).
Only the men and women who smoked previously but had quit by the first survey in 1975 were not at increased risk of depressive symptoms, and may have even reduced the likelihood of depression by 1990.
Persistent smoking appears to be the strongest predictor of depressive symptoms, the investigator added. In terms of the underlying mechanism, "it is very important to distinguish between the effects of acute nicotine ingestion and the consequences of chronic exposure to the multitude of noxious compounds contained in cigarette smoke (over 4000 compounds, many of them bioactive, cytotoxic, carcinogenic, or mutagenic)."
作者:admin@医学,生命科学 2011-02-14 18:24