quitting, depression and suicide risk
By Dr. W.A. Arrindell, psychologist
Everyone probably knows that smoking is the number one cause of lung cancer. Smokers are also at a higher risk of developing cognitive problems like Alzheimer's disease or other forms of dementia (severe memory loss), heart disease, and respiratory diseases. Stopping smoking substantially reduces these health risks. Startling new research demonstrates that smokers may actually also be more likely than non-smokers to become depressed and to take their own lives and that interventions or public health policies aimed at smoking cessation or smoke-free air policies may reduce these risks.
Depression
There is a strong association between smoking and depression. People with current or past depression are about twice as likely to be current smokers and smoke more cigarettes per day than people without depression. Three broad explanations have been advanced to explain this association. First, smoking and poor mental health might have common causes. Studies conducted with twins have demonstrated that there is some evidence to assume that shared genes predispose people to both smoking and depression. Second, people with poor mental health smoke to self-medicate, that is, they do so to relieve anxiety or regulate feelings of distress and suboptimal mood (depression). Third, smoking might cause or worsen mental health problems.
Motivation to quit
Contrary to what many people believe, scientific evidence suggests that smokers with depression are highly motivated to quit smoking. Quitting is difficult, especially in the first two weeks or so following smoking cessation. Quitting implies withdrawal from the addictive substance which is found in tobacco, namely nicotine. Nicotine creates a chemical dependency leading the body to develop a need for a certain level of it at all times. Withdrawal from nicotine leads to withdrawal symptoms. These include both physical (bodily) and mental symptoms. Physical symptoms may include tingling in hands and feet, headache, sweating, sore throat, coughing, breathing problems. Mental symptoms may include anger and irritability, mood swings, boredom, anxiety, depression, frustration, restlessness. A major withdrawal symptom is craving for cigarettes.
What is already known on this topic:
-Many smokers want to quit but continue smoking as they believe smoking has mental health benefits.
-Health professionals are reluctant to deal with smoking in people with mental disorders in case stopping smoking might worsen mental health.
-Public health interventions for smoking reduce bodily health risks.
What these studies add
-Smoking cessation is associated with an improvement in mental health in comparison with continuing to smoke.
-Public health interventions for smoking could also reduce risk for suicide and mental disorders in general.
Misattribution
Smokers with or without a depression or other mental disorder might think that smoking provides mental health benefits. By smoking to reduce distress, smokers might be erroneously attributing the ability of cigarettes to set aside nicotine withdrawal symptoms as a beneficial effect on mental health. Smokers experience anxiety, depression, irritability, boredom, etcetera (withdrawal symptoms) when they have not smoked for a while, and these feelings are reliably experienced as relieved by smoking, thus creating the perception that smoking has beneficial psychological effects, when, in fact, it is smoking that caused these psychological disturbances in the first place.
Relevance
Gemma Taylor (doctoral researcher), Professor Ann McNeill, Professor Paul Aveyard and co-workers of the University of Birmingham, University of Nottingham, King's College London, and University of Oxford (all located in the United Kingdom) pointed out that whatever the cause, the association between smoking and poor mental health warrants attention from a preventative point of view. Taylor and her co-workers argued that smokers might be less likely to stop smoking if they believe that their mental health will suffer, and health professionals might be reluctant to intervene with some smokers because they believe that this might be detrimental to their mental health. As a result, Taylor and her associates pointed out, people with mental health disorders have a life expectancy eight years less than the general population, and much of this difference could be because of smoking.
In a similar vein, Dr. Richard A. Grucza, Dr. Frank J. Chaloupka and co-workers from Washington University School of Medicine (St. Louis, MO, USA) and University of Illinois at Chicago (Chicago, IL, USA) argued that if smoking were a direct risk factor for depression and, by extension, suicide, this would have significant implications, not only for clinical practice but also for public health campaigns because it would establish smoking as a common and easily modifiable risk factor for suicide. In this case, more effective tobacco control policies and other smoking interventions could be promising means for suicide risk reduction.
Study 1
Taylor and colleagues conducted a systematic review of studies to examine the difference in change in mental health between people who stop smoking and people who continue to smoke. Their hypothesis was that smokers who give up smoking would experience an improvement in mental health as a result because they would no longer experience multiple episodes of psychological distress induced by withdrawal. The authors published their findings in the British Medical Journal 2014; 348:g1151 doi: 10.1136/bmj.g1151.
Results 1
Taylor and her colleagues searched through data bases for relevant studies from inception to April 2012 and selected those that assessed in adults mental health before smoking cessation and at least six weeks after cessation or first-measurement. Studies included both healthy and patient populations. Taylor and her associates found 26 studies that assessed mental health with questionnaires designed to measure anxiety, depression, mixed anxiety and depression, psychological quality of life, positive affect (for example, happiness) and stress. Follow-up mental health scores were measured between seven weeks and nine years after first-measurement (baseline). The authors found that anxiety, depression, mixed anxiety and depression, and stress significantly decreased between first-measurement and follow-up in quitters compared with continuing smokers. In addition, both psychological quality of life and positive affect significantly increased between first-measurement and follow-up in quitters compared with continuing smokers. Importantly, the magnitudes of the changes were equal for people with and people without psychiatric disorders. Moreover, the changes were at least as large as the magnitudes in change that are observed when patients are treated with antidepressants for mood or anxiety disorders.
Study 2
Severe depression is a risk factor for entertaining thoughts of death and dying, and therefore also for attempted and successful suicide. Not surprisingly then, because smoking is associated with depression, smokers also exhibit elevated risk of suicide. This fact inspired Dr. Richard A. Grucza and co-workers to investigate whether smoking policy interventions could reduce suicide risk. In doing so, these researchers studied whether state-level policy interventions – increases in cigarette excise taxes and strengthening of smoke-free air laws (for example, indoor smoking bans) – corresponded to reductions in suicide risk during the 1990s and early 2000s. In addition, the authors examined whether states with restrictive smoking policies experienced any changes in suicide rates, relative to those that did not implement policies as aggressively (Nicotine & Tobacco Research 2014 doi:10.1093/ntr/ntu106).
The researchers combined data on suicide deaths from the U.S. Multiple Cause of Death files, years 1990-2004, in all 50 U.S. states with living population data from the same period. It was also ascertained whether the deceased may have been a smoker. Next, Dr. Grucza and his associates pinpointed the state where the suicide took place and how aggressive that state's tobacco policies were.
Results 2
Grucza's research team demonstrated that during the period 1990 to 2004, states which had adopted aggressive tobacco-control policies saw their suicide rates decrease relative to the national average. The team found the opposite to be true in states with lower cigarette taxes and softer policies towards smoking in public. In those states, during the same time period, suicide rates went up relative to the national average. Grucza and his associates estimated that a one dollar increase in cigarette excise taxes across the United States could result in a 10.5% relative reduction in risk of suicide. They point out that "given an adult suicide rate of 16.1 per 100,000 in 2010 ..., this would correspond to nearly 4,000 fewer suicides per year" (2014, p. 6).
Overall conclusions
Smoking may contribute to depression, other mental disorders, and suicide risk. People erroneously believe to be smoking in order to relieve mental distress (misattribution). Facts, however, clearly suggest that mental distress may well result from smoking behaviour. The data presented in this contribution are consistent with mounting evidence showing that tobacco control policies may reduce the frequency of occurrence of psychiatric disorders and substance abuse – two key risk factors for suicide. Other studies have shown that increases in cigarette excise taxes and stricter smoke-free air policies (to reduce second-hand smoking) are associated with decreased alcohol consumption and alcoholism remission; that regular smoking is associated with new onset mood and anxiety disorders; that increases in cigarette excise taxes are associated with a reduction in the number of people reporting subjective feelings of unhappiness and that this observation is limited to people with high probability of smoking.
Smoking cessation is associated with reduced mental distress and improved positive mood and quality of life compared with continuing to smoke. Both individual and national interventions for smoking could reduce risk for mental distress and suicide.
