- Smoking is the leading cause of preventable diseases and deaths worldwide.
- Quitting smoking renders health benefits regardless of age, how much, or how long a person has smoked.
- A new major review highlights three top-performing smoking cessation strategies.
- Researchers found that these strategies may be more effective in combination with behavioral therapies.
- Behavioral therapies and financial incentives also show strong potential for successful smoking cessation without added medications.
Findings from papers published between 2021 and 2023 indicate that varenicline, cytisine, and nicotine e-cigarettes have increased success rates with smoking cessation.
CTAG published 14 reviews of tobacco addiction treatments between 2021 and 2023.
The group outlined key findings, such as new results and updated conclusions to previous works. They also summarized key abstinence results and adverse side effects from treatments.
The researchers rated evidence quality using the GRADE parameters of study limitations, consistency of effect, imprecision, indirectness, and publication bias.
Certainty ratings ranged from “high certainty” to “very low certainty”.
Evidence revealed that common medicines varenicline, cytisine, and nicotine e-cigarettes were the most effective treatments.
Varenicline is a prescription oral tablet designed to help with smoking cessation.
Cytisine, also called cytisinicline, is a plant-based prescription or over-the-counter oral tablet currently available in Canada and Europe. Multiple U.S. studies have been conducted in hopes of securing Food and Drug Administration approval.
Both compounds bind to receptors that respond to nicotine. The medicines can help nicotine withdrawal symptoms and block nicotine-generated reinforcement when smoking.
According to Dasgupta, “most pulmonologists encourage adults who smoke to use established and traditional pharmacotherapies such as varenicline, bupropion, and nicotine replacement therapies rather than e-cigarettes.”
This review emphasized high-certainty evidence that varenicline is more effective than bupropion or a single form of NRT at helping with smoking cessation. However, evidence that it can be as or more effective than dual-form NRT was low-certainty.
People using varenicline may be more likely to experience serious side effects than those not using it. However, cytisine consumption was associated with fewer reports of serious adverse events than varenicline use.
The review also found high-certainty evidence that bupropion, an antidepressant, helped more with smoking cessation than a placebo or no medications.
However, people receiving this drug experience more serious adverse events — including some of a psychiatric nature — than those receiving placebo.
The CTAG team observed high-certainty evidence that fast-acting NRT gums, lozenges, and sprays combined with transdermal patches were more effective than single-form NRT alone. Evidence was mixed regarding effectiveness of higher NRT doses.
According to a 2021 CTAG overview, behavioral therapy for smoking cessation may increase quit rates at 6 months or longer. This benefit was evident with or without smoking cessation medications, but slightly lower with medications.
The CTAG researchers say that further evidence is needed to confirm benefits of specific therapy services, such as text messages, email, lay health advisors, and intervention content with motivational components. They did find that combining multiple components may increase chances of successful quitting.
Research on mindfulness-based therapy yielded no clear evidence of benefit or harm. The studies reviewed on this treatment varied greatly, though, and future research may reach different conclusions.
The Cochrane Review of e-cigarettes (ECs) is a living systematic review, updated monthly. To date, it has found high-certainty evidence that ECs with nicotine lead to higher quit rates than NRT.
Only moderate-certainty evidence suggests that ECs with nicotine may be more effective than ECs without nicotine for smoking cessation.
The CTAG researchers reported that: “Overall, findings suggested switching from exclusive smoking to exclusive vaping led to reduced levels of biomarkers of potential harm. The same was also found for moving from exclusive smoking to dual use of combustible and ECs, although the magnitude of reduction in biomarkers of harm was smaller.”
Thus, the scientists believe that giving ECs to smokers may not lead to higher levels of exposure to harmful chemicals.
MNT spoke with the current study’s lead author, Jonathan Livingstone-Banks, PhD, a lecturer and senior researcher in evidence-based healthcare at the University of Oxford, about his and his colleagues’ review.
Livingstone-Banks emphasized that:
“The most important thing is helping people to quit combustible tobacco use. While nicotine isn’t harm-free, most of the harm from smoking comes from other components of burnt tobacco, not from the nicotine.”
“E-cigarettes also have features that may make them easier to quit, such as the ability to control their nicotine content or switch between flavors. However, more research is needed to fully understand the process of quitting vaping and what help is effective in supporting it,” he added.
The CTAG team noted “very low-certainty evidence” that behavioral support from dental professionals leads to higher quit rates.
However, the researchers found moderate-certainty evidence of greater success when dental professionals combine behavioral support with pharmacotherapy.
The cohort reported moderate-certainty evidence that counselling, cost-free cessation medicines, and tailored reading materials correlate with increased smoking cessation. Offering biomedical risk feedback did not appear to affect quit rates.
The authors examined a recent review that highlighted associations between smoking cessation and reduced risk of major cardiovascular events and death from cardiovascular disease.
The CTAG team argued that these associations could be causal, as quitting is linked to the restoration of endothelial and platelet function.
Results from another extensive review suggest that quitting smoking is associated with improvement in symptoms of anxiety and depression. These improvements were evident in subpopulations including people diagnosed with mental illnesses.
“Smoking is much more common among adults with mental health conditions, like depression and anxiety, than in the general population. We don’t fully understand why this is, and more research is needed to understand this link.”
MNT also discussed this review with Thomas Banta, a clinical mental health counselor specializing in addiction. He was not involved in the review.
Banta, who told us he himself is a former smoker, explained how smoking cessation could foster improvement in anxiety symptoms.
“Nicotine has a short half-life, so a person starts to experience discontinuation symptoms after about an hour of no smoking—anxiety/stress increases, as well as craving and mental preoccupations,“ he told us.
“People become irritable and restless. Ingesting nicotine relieves these sensations, giving people the illusion of anxiety reduction, but it is actually one of the culprits causing the anxious symptoms,“ Banta noted.
Dasgupta praised the study for providing “a thorough review of various smoking cessation methods, including medications, ECs, and behavioral strategies, offering multiple options for people trying to quit.”
Yet, the review’s authors acknowledge the need for more research, although their review group no longer receives funding. They mentioned that more trials are necessary to compare smoking cessation medicines and report safety data.
They hope that future studies will explore individual tailoring for behavioral support.
ECs “remain a priority area of research” regarding their long-term safety and effectiveness as a smoking cessation aid. The CTAG researchers also mentioned the need for more evidence on heated tobacco products, which are understudied.
