, that is.
Smoking kills. Everyone knows that. The message is reinforced by health warnings on packets, government campaigns and common sense. Smoking messes with your body in so many ways. However, when it comes to a smoker's mental health, numerous studies have shown tobacco smoke to actually have positive effects.1
Smoking makes me feel good!
"Smoking helps me relax", "It helps me concentrate", "smoking feels good"... Statements like these by smokers are common, but are usually dismissed as tricks of nicotine addiction. It's not actually making you feel better, they say, it's the nicotine withdrawal symptoms that makes you feel worse. While there is some truth in this assertion, the evidence points overwhelmingly to the fact that in many cases, nicotine can improve mental state. These cases are usually where the smoker also suffers from mental health problems.
While anti-smoking campaigns have generally proven effective, with rates of smoking in developed countries dramatically lower than they were a generation ago, the exception to this trend is among sufferers of mental illness. Rates of smoking among these groups are significantly higher than in the population as a whole. Among patients with schizophrenia, studies have shown smoking rates between 742 and 88%3, compared to a figure in the population as a whole of around 20%. Among patients with depression, a 56% rate has been shown in one UK study4. There is also evidence that depressive smokers find it much harder to quit5. Of course, a correlation like this in no way shows the reasons behind these figures. Some have postulated that smoking causes depression, though little evidence has been found to support this. Some evidence has been found to show that a tendency towards nicotine addiction and to depression may have shared genetic factors. However, the bulk of the evidence seems towards the use of nicotine as a form of self-medication6, and a suprisingly effective one at that.
Why does smoking help?
When you smoke, nicotine is absorbed by the lungs, enters the bloodstream and makes its way towards the brain. There it binds to receptors for dopamine 7, the brain's reward chemical. This accounts for the feeling of well-being experienced when smoking and is the basis of most addictive substances' appeal8. Among people with depression, dopamine levels are often unusually low, so this is counteracted by the spike.
However, this short-lived effect is only part of smoking's appeal for the depressed or otherwise mentally ill person. Several studies have also shown that tobacco smoke acts as a monoamine oxidase inhibitor (MAOI). 9,10,11 Monoamine oxidase is another brain chemical that is involved in the breakdown of dopamine. The studies found that levels of MAO were significantly lower in smokers than among non-smokers. This is interesting for several reasons. MAOIs are often used as anti-depressants, but have also been shown to help in the treatment of Parkinson's disease12. This may explain findings showing increased depression among people trying to give up smoking13, but also, controversially, the lower rates of Parkinson's found among smokers. When someone stops smoking, MAO levels gradually return to normal. This is likely to cause a reduction in the anti-depressant effects felt, and so the depression returns. Some studies have even shown that starting smoking can have beneficial effects for depressed non-smokers14.
Furthermore, dopamine is known to play a significant but unclear role in schizophrenia8. This is an area where more study is needed, but it may eventually offer some explanation for the dramatically high levels of smoking among schizophrenic people.
So should I start smoking?
Of course not, and if you already smoke, you should quit. Smoking kills. However, mental illness also kills. In fact it is one of the developed world's biggest killers. So if smoking really does help sufferers, as these studies appear to show, maybe there can be a case made. This is a controversial subject and it is most likely that smoking's many negative effects outweigh these benefits, but it is interesting to note that smoking does have some health benefits. More research is needed, as many of the causes and effects are still barely understood, but in the meantime it is helpful to know some of the reasons why people smoke and why it is so hard to give up. I also plan to use it as an excuse for not quitting, because I am weak.
This writeup was inspired by an article1 I read today, along with my own failure to give up smoking. Much of the material was found with the help of material15 on the website of ASH, a UK anti-smoking research group. Ironic.
- James "Why I'm still dying for a cigarette" The Observer 29/12/2002 http://www.observer.co.uk/focus/story/0,6903,866130,00.html
- Meltzer H, Gill B, Petticrew M et al. "Economic activity and social functioning of residents with psychiatric disorders" (OPCS Surveys of Psychiatric Morbidity in Great Britain Report 6). 1996 http://www.doh.gov.uk/pub/docs/doh/newsurvey4.pdf
- Lohr & Flynn, "Smoking and Schizophrenia" Schizophrenia Res; 8:93-102; 1992
- Meltzer H, Gill B. Petticrew M et al. "Economic activity and social functioning of adults with psychiatric disorders" (OPCS Surveys of Psychiatric Morbidity in Great Britain Report 3). 1995 http://www.doh.gov.uk/pub/docs/doh/newsurvey4.pdf
- Glassman AH, Stetner F, Walsh BT et al. "Heavy smokers, smoking cessation, and clonidine. Results of a double-blind randomized trial." JAMA; 1988; 259: 2363-6 http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3367452&dopt=Abstract
- Lerman C, Caporaso N, Main D, Audrain J, Boyd NR "Depression and Self-Medication with Nicotine: The Modifying Influence of the Dopamine D4 Receptor Gene" Health Psychology; 17: 56-62.
- Voryxnyx "Nicotine" everything2 writeup; 2002
- enth "dopamine" everything2 writeup; 2002
- Fowler JS, Volkow ND, Wang GJ, Pappas N,
Logan J, MacGregor R, Alexoff D, Shea C, Schlyer D,
Wolf AP, Warner D, Zezulkova I, Cilento R "Inhibition of monoamine oxidase B
in the brains of smokers" Brookhaven National Laboratory,
Upton, New York 11973, USA.
Nature 1996 Feb 22; 379(6567):733-6 http://www.biopsychiatry.com/smokemao.htm
- Berlin I, Spreux-Varoquaux O, Said S, Launay JM "Effects of past history of major depression on smoking characteristics, monoamine oxidase-A and -B activities and withdrawal symptoms in dependent smoker" Department of Clinical Pharmacology,
Hopital Pitie-Salpetriere, Paris, France.
Drug Alcohol Depend 1997 Apr 14; 45(1-2):31-7 http://www.biopsychiatry.com/smoking.htm
- Fowler JS, Volkow ND, Wang GJ, Pappas N,
Logan J, MacGregor R, Alexoff D, Wolf AP,
Warner D, Cilento R, Zezulkova I "Neuropharmacological actions of cigarette smoke: brain monoamine oxidase B (MAO B) inhibition" Department of Chemistry and Medicine,
Brookhaven National Laboratory, Upton, NY 11973, USA.
J Addict Dis 1998; 17(1):23-34 http://www.biopsychiatry.com/smokmaob.htm
- Gorell JM, Rybicki BA, Johnson CC, et al., "Smoking and Parkinson's disease.
A dose-response relationship." Neurology, 38, pp. 1558-1561, 1988
- Niaura R, Britt DM, Shadel WG et al. "Symptoms of depression and survival experience among three samples of smokers trying to quit." Psychology of Addictive Behaviours; 2001; 15: 13-17. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11255933&dopt=Abstract
- Malpass D. "Smoking and mental health seminar." November, 2001. Presentation.
- McNeill "Smoking and mental health - a review
of the literature" St George’s Hospital Medical School
London, Action on Smoking and Health. http://www.ash.org.uk/html/policy/menlitrev.html