Smoking is clearly tied to negative physical health effects, but what about mental health? Researchers behind a new review set out to explore this topic.
These researchers looked at a number of long-term studies measuring the mental health effects of quitting smoking.
This review found that quitting smoking was associated with improvements in a number of measures for mental health, including reduced anxiety and depression.
According to the authors of this review, who were led by Gemma Taylor, a doctoral researcher at the School of Health and Population Sciences at the University of Birmingham in the United Kingdom, even though smoking's effect on physical health has been clearly understood for some time, its relationship to mental health is less clear.
Taylor and team explained that many smokers report that the habit helps ease feelings like anxiety, depression and stress.
To explore the relationship between quitting smoking and mental health, the researchers reviewed 26 long-term studies measuring adults' mental health before they quit and at least six weeks after they quit.
The studies all used questionnaires to measure factors like participants' levels of anxiety, depression, stress, quality of life and positive mood. The studies' follow-up times ranged from seven weeks to nine years, with an average follow-up period of six months.
Some studies involved the general population, while some focused on pregnant women, those with a chronic physical condition or those with a chronic mental condition. The average age of participants was 44 years old, and on average, the participants smoked 20 cigarettes a day.
Taylor and team found that when comparing quitting smoking and continuing to smoke, quitting smoking was associated with an improvement in a variety of mental health measures. Quitting smoking was associated with reduced anxiety, depression and stress and an increase in quality of life and positive mood at the follow-up.
The researchers noted that this association was seen in all types of participants, including people with mental health issues.
"The effect sizes are equal or larger than those of antidepressant treatment for mood and anxiety disorders," Taylor and team wrote.
"Their finding, that smoking cessation was associated with general improvements in mood and anxiety symptoms and stress, is important because it suggests that individuals, both with and without diagnosed mental illness, may improve not only their physical health but also their mental health when they stop smoking," said Eric Collins, MD, Physician-in-Chief at Silver Hill Hospital and Associate Clinical Professor of Psychiatry at Columbia University College of Physicians & Surgeons. "It is also important because it suggests that most smokers are mistaken in their belief that smoking helps their long-term mood and anxiety, because smoking acutely relieves nicotine withdrawal symptoms, which often include depressed mood, anxiety symptoms, and irritability."
It is important to remember that this study showed a relationship between quitting smoking and improved mental health, but not necessarily that one caused the other. Further research is needed to explore this topic.
As Dr. Collins explained, "The observed association between smoking cessation and improved mental health does not prove that smoking cessation produced better mental health. It is possible, for example, that only people whose mental health improved significantly were able to stop smoking. But the authors make a strong case that such alternative explanations for the observed correlation are not at all likely."
The researchers noted that the findings could help convince smokers that smoking does not carry mental health benefits.
According to Dr. Collins, "If these findings hold up, they should encourage more and more psychiatrists to focus aggressively on helping their patients stop smoking, because the observed correlation was seen in individuals both with and without mental illness. This is especially important for psychiatrists, because patients with mental illnesses smoke at considerably higher rates than the general population. Efforts to help them stop smoking would not only lengthen the average life span but also improve quality of life."
This study was published online February 13 in BMJ. Several of the researchers reported receiving payment or grants from a variety of organizations, including the UK Centre for Tobacco and Alcohol Studies, manufacturers of smoking cessation aids and pharmaceutical companies, including Pfizer.