Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Persistent smokers may have higher risk to become depressed than never smokers

22.05.2007
Based on a Finnish study, persistent smokers may have higher risk to become depressed in comparison to never smokers. Also those smokers who quit have an elevated risk of depressive symptoms in short run. However, in long run this risk declines to the level of never smokers. In other words, both completely smoke-free life style and successful smoking cessation in long run seem to protect from depressive symptoms.

It is known that depression is associated with cigarette smoking, but the nature of this association is discussed under various hypotheses. First, according to the so called self-medication hypothesis, those who suffer from depressive symptoms smoke cigarettes in order to alleviate their symptoms. According to the second assumption, chronic persistent smoking may have a role in the etiology of depression. The third hypothesis suggests that there is a reciprocal mechanism between smoking and depression. The fourth hypothesis says that there are shared underlying genetic factors explaining this co-morbidity.

This study conducted in the Department of Public Health at the University of Helsinki explored, which of those assumptions would be supported by the data, when smoking behavior and changes in it is considered as a predictor of depressive symptoms. The researchers had access to the data collected within the Finnish Adult Twin Cohort Project. There were about four thousand male and five thousand female twins, whose health and health behavior were followed-up through 15 years.

Data on smoking behavior and changes in it between 1975 and 1981 were analyzed as a predictor of depressive symptoms measured in 1990. The analyses were adjusted for other factors known to predict depression. Because the data consisted of twins it was possible to test the causality between smoking and depression by using twin pairs discordant for depression, where the twin without depression served as a matched control for his/her co-twin with depression. Additionally, it was possible to explore potential shared genetic influences underlying the association.

The results suggest that first, persistent chronic cigarette smoking predicts depressive symptoms. However, when adjusted for other factors associated with depression, the elevated risk of persistent smoking remained significant among men only. ”The result that chronic smoking may actually have a role in the etiology of depression, may be surprising, as nicotine as such – in short term – is assumed to have some positive effects on mood”, says Dr. Tellervo Korhonen from the Department of Public Health at the University of Helsinki, and continues: ”We should look for explanation to our result from long term effects of cigarette smoking, from addiction mechanisms and from other substances than nicotine within tobacco smoke.”

Secondly, there was evidence suggesting that those smokers who had quit had elevated depression risk in relatively short term. The association of quitting smoking and depressive symptoms gives us indirect evidence on the self-medication hypothesis. Dr. Korhonen emphasizes, however, the further evidence within the same study showing that those smokers who had quit successfully and remained abstinent through the follow-up did not have elevated depression risk compared to the never smokers. This may reflect a relatively long recovery process from the adverse effects of cigaret1te smoking.

”The mechanisms underlying the association between smoking and depression are very complicated. Although nicotine as such may have short term positive effects on concentration and possibly on mood, long term exposure to tobacco smoke may be one risk factor in development of depression. However, this mechanism is still relatively unknown. Thus, there is need for further research and evidence in order to make an unambiguous statement that ‘smoking cigarettes cause depression’. Examination of potential shared genetic vulnerability for both tobacco dependence and depression is among the further challenges”, Dr. Korhonen is discussing the evidence so far. According to Korhonen, one can already say that – as in prevention of many other diseases – also in prevention of depression smoke-free life and successful smoking cessation seem to have a positive impact.

This report is based on a research article published in the Psychological Medicine –scientific journal. The authors include researchers from the University of Helsinki, the National Public Health Institute, the Finnish Institute of Occupational Health and the Harvard University, Boston, USA.

Paivi Lehtinen | alfa
Further information:
http://www.helsinki.fi

More articles from Studies and Analyses:

nachricht Antarctic Ice Sheet mass loss has increased
14.06.2018 | Technische Universität Dresden

nachricht WAKE-UP provides new treatment option for stroke patients | International study led by UKE
17.05.2018 | Universitätsklinikum Hamburg-Eppendorf

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Carbon nanotube optics provide optical-based quantum cryptography and quantum computing

19.06.2018 | Physics and Astronomy

How to track and trace a protein: Nanosensors monitor intracellular deliveries

19.06.2018 | Life Sciences

New material for splitting water

19.06.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>