Introduction
Tobacco smoking remains a significant public health challenge, contributing to substantial morbidity, mortality, and economic burden worldwide [
1]. The long-term use of pharmacological interventions has been associated with adverse outcomes on both physical and psychological health in tobacco users [
2,
3]. Tobacco smoking is linked to multiple diseases, including cardiovascular diseases (particularly stroke and coronary heart disease), cancer, chronic obstructive pulmonary disease [
4], periodontal health conditions [
5], and many other metabolic diseases [
6]. Additionally, tobacco use is a contributory risk factor for various infections, bone-related conditions, reproductive issues such as premature ejaculation [
7], delayed wound healing [
8], and psychological disorders [
8]. It is well-established that tobacco-related complications are associated with increased premature mortality among smokers [
9].
Effective cessation strategies and interventions are urgently required to mitigate the ripple effects of tobacco use. Various interventions and strategies have been tested, yielding variable efficacy and success rates [
10]. Smoking cessation interventions may involve pharmacological, non-pharmacological, or behavioral approaches [
11], applied either as standalone therapies or in combination across different age groups [
12].
Considering concerns regarding side effects, prolonged use [
13], and the high costs associated with long-term pharmacological treatments, there has been an increasing shift toward non-pharmacological treatments [
14]. Non-pharmacological interventions include behavioral skills training using cognitive behavioral therapy (CBT) [
15], incentive-based methods, reinforcement behavior techniques [
15–
17], and motivational and brief interviewing approaches [
18,
19].
CBT is a structured umbrella psychological intervention that has shown promise in addressing tobacco cessation [
20]. This approach focuses on identifying and modifying maladaptive thought patterns and dysfunctional behaviors [
21]. Furthermore, CBT aids individuals in developing alternative thinking and behaviors to reduce psychological stress and prevent relapse episodes [
22].
CBT is typically delivered through multiple sessions of 45 to 60 minutes, emphasizing problem-solving skills, recognition of social or environmental cues that trigger tobacco use, and education about the quitting process. Additionally, CBT teaches adaptive coping strategies to mitigate relapse risk [
20,
23]. Thus, CBT represents a more intensive intervention than brief counseling alone and is associated with higher quit rates among smokers [
24]. CBT delivery formats include individual face-to-face sessions [
25], group therapy [
26], and digital platforms [
27]. Although previous literature has demonstrated CBT’s effectiveness in smoking cessation, uncertainty remains regarding its efficacy in maintaining abstinence among tobacco users, particularly as a standalone treatment over longer follow-up periods. Clarifying this issue could inform the design of more effective strategies for early smoking cessation across diverse age groups. Additionally, the comparative effectiveness of CBT versus standard care or minimal interventions for smoking cessation remains uncertain and requires pooled data analysis from randomized controlled trials (RCTs).
This systematic review and meta-analysis aimed to quantify the impact of CBT interventions on smoking cessation by synthesizing evidence from RCTs. This review focused on abstinence rates at the end of treatment and at 3-month and 6-month follow-ups.
Therefore, considering the substantial individual studies available and recent advancements in intervention methods, our objective is to provide a comprehensive pooled analysis regarding the effectiveness of CBT in achieving abstinence among healthy smokers at the specified follow-up intervals (3 and 6 months).
Materials and Methods
Eligibility Criteria
The review included studies of sufficient quality that assessed abstinence rates at the end of treatment, as well as at 3-month and 6-month follow-up intervals.
This review specifically encompassed publications employing RCT or clinical trial designs, focusing on smoking cessation, treatment outcomes, or smoking quit rates. Included studies utilized CBT, either independently or in combination with other interventions, for smoking cessation or quitting among healthy adolescent or adult participants aged 12 years and older. The inclusion criteria were restricted to research published in English between January 2001 and September 2024 and available electronically in full text.
We excluded studies that implemented internet-based, web-based, or mobile app interventions, as well as those that employed treatment conditions other than placebo or standard care in the control group. Additionally, reviews, meta-analyses, qualitative studies, non-RCTs, editorials, observational studies, studies focusing exclusively on pharmacotherapy, and studies in which smoking cessation was not a primary or secondary outcome were excluded. Rayyan software was used to assist in database screening according to the inclusion criteria [
28]. All authors reviewed the articles, and those not meeting the inclusion criteria were excluded. Cross-referencing of both excluded and selected studies was performed with co-authors’ consensus.
Information Sources
The search for this review was conducted between September 2024 and November 2024. A comprehensive and systematic literature search was carried out across major electronic databases, including PubMed, Cochrane Library, PsycINFO, Embase, and ClinicalTrials.gov.
Search Strategy
The search was performed using major online databases, refined by filters for the date range (January 2001 to September 2024) and limited to RCTs and controlled clinical trials published in English. The primary keywords and phrases used to identify relevant studies included: “cognitive behavioral therapy,” OR “cognitive behavioral treatment,” OR “CBT,” AND “smoking cessation,” OR “tobacco cessation,” OR “quit smoking,” AND “randomized controlled trials,” OR “clinical controlled trial,” AND “smoker,” OR “tobacco user(s),” along with other related MeSH terms. The most recent included study was published on February 27, 2024 [
29]. Additionally, 2 reviewers (P.M., R.K.) thoroughly screened references from selected studies to locate studies potentially missed during the primary search. Complete details of the search strategy are provided in
Supplementary Material 1.
Extracted studies underwent a screening process based on titles, followed by an evaluation of independent and outcome variables. This meta-analysis adhered to the PICOTS framework, defined as follows: population/patient (P)—healthy smokers aged 12 years and above; intervention/indicator (I)—CBT; comparator/control (C)—standard care, consultation, health education, or brief advice; outcome (O)—smoking cessation measured at 3-month and 6-month follow-up intervals; time (T)—studies published from January 2001 to September 2024; and study design (S)—RCTs assessing the effectiveness of CBT compared with control or standard treatment conditions (
Table 1).
Intervention
The interventions analyzed included various forms of CBT aimed at assessing their effects on the point-prevalence of smoking cessation among healthy individuals. Out of 7 studies employing cognitive behavioral approaches, 5 administered standard CBT [
29–
33], while 1 adopted a self-help CBT approach [
34], and 1 used a smokeless smoking reduction program consisting of 4 weekly sessions of 2.5 hours each [
35].
The interventions were delivered by researchers through group sessions with varying participant sizes: groups of 3 to 12 participants [
34], 8 to 9 participants [
29], 10 participants [
31], and 7 (5–9) participants [
35]. Sessions ranged in duration from 15 to 30 minutes [
33,
35] to 60 to 90 minutes [
29–
31], up to 2.5 hours [
35], with sessions occurring weekly or twice weekly over periods ranging from 1 week to 52 weeks. Some studies provided telephone consultations to individual participants during weeks 2 and 5 of the program [
35], and 1 study delivered individual counseling to the participants at baseline [
33].
Study Selection Process
The outcomes assessed were smoking abstinence events at the end of treatment, as well as at 3 and 6 months among healthy smokers. Two authors (R.K. and P.M.) thoroughly reviewed all studies to gather information on the assessment measures employed. A consensus was reached to include only the outcomes assessed by the most frequently used instruments in this systematic review and meta-analysis. Additionally, studies reporting smoking abstinence data in frequencies or events were included. Studies reporting outcome measures in means or other formats were excluded. All outcome assessments utilized standardized tools (
Table 1). Most studies conducted follow-up assessments at 1, 3, and 6 months [
27,
29,
30], 2 studies had follow-ups at 3 and 6 months [
31,
34], and 3 studies had follow-ups at 1, 3, 6, and 12 months [
32,
33].
After exporting records from databases into Microsoft Excel, duplicate entries were removed. Subsequently, guided by eligibility criteria, 2 reviewers independently evaluated titles and abstracts of each record to identify potentially eligible studies. Following this screening, full texts were retrieved and thoroughly examined for final inclusion in the analyses. Two researchers (R.K. and K.B.) analyzed and extracted data from relevant articles. One researcher (P.M.) conducted data extraction, while another (R.K.) verified selected studies to ensure alignment with objectives and inclusion criteria. In case of discrepancies, 2 additional reviewers (V.A.S. and K.B.) were consulted to resolve disagreements. Ultimately, a senior reviewer (G.S.C.) provided a final opinion before the inclusion of records in the final analyses.
Data Collection and Processing
A Google Sheet was used to extract information, ensuring the consistency and accuracy of the collected data. Information from the studies was organized into tabular format and categorized according to the author’s surname, study design, country, target participants, presence of sample size estimation (yes/no), actual sample size, age (in years), gender distribution, types of intervention and control groups, duration of the intervention, group size, follow-up intervals (days per weeks), and outcome assessment measures (
Table 2) [
29–
35].
Assessment of Study Risk of Bias
The risk of bias in the included studies was evaluated using the Cochrane review criteria [
36]. Each study was assessed across 6 evidence-based domains: allocation concealment and random sequence generation (both addressing selection bias), blinding of participants and personnel (performance bias), blinding of outcome assessment (detection bias), incomplete outcome data (attrition bias), and selective reporting (reporting bias). The risk of bias for each domain was categorized as low, high, or unclear. In some instances, corresponding authors were contacted to provide missing information or clarify findings. If uncertainties remained after receiving responses, decisions were made through consensus among authors. Detailed methodological findings related to the Cochrane risk assessment domains are presented in
Table 3 [
29–
35].
Data Analysis
Pooled data were statistically analyzed using Cochrane Review Manager software (RevMan ver. 5.3; Cochrane) [
37]. In all analyses, heterogeneity was evaluated using the
I2 statistical approach, which quantifies the degree of inconsistency among study results. A fixed-effect model was employed to analyze findings in this meta-analysis when heterogeneity was less than 50%, minimizing heterogeneity risk. This model was selected based on the criterion of a
p-value less than 0.05 and an
I2 value lower than 50%. The odds ratio (OR), with a 95% confidence interval (CI), was calculated for the abstinence rate outcomes. The authors included abstinence rates at 2 follow-up intervals—3 months and 6 months—in this meta-analysis, considering inconsistencies and variations across studies to mitigate potential bias in the meta-analytic outcomes.
Results
Study Selection
The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines [
38] (
Figure 1) guided the research process for study identification, selection, eligibility assessment, and final inclusion. Initially, 1,514 articles were identified, of which 1,013 were excluded due to duplication. Application of predefined inclusion and exclusion criteria to titles and abstracts reduced the number of eligible studies to 455. After comprehensive full-text evaluations, 7 articles met the criteria and were included in the final meta-analysis (
Supplementary Material 2).
Study Characteristics
The study characteristics are summarized in
Table 1. Seven studies involving a total of 1,438 participants were analyzed, comprising 769 participants in intervention groups and 671 in control groups, with follow-up durations ranging from 1 to 12 months at various intervals. Six studies delivered interventions through a face-to-face approach, while 1 study [
35] used a digital follow-up. Comparators included a health promotion intervention [
34], a brief consultation along with waitlist control [
35], very brief advice [
27], health education [
30–
32], hypnotherapy [
29], and minimal interventions [
33].
Two studies had an additional intervention arm [
33] and control arm [
35], respectively, increasing the total number of participants in the intervention group compared to the control group. Three studies were conducted in Germany [
29,
33,
35], 1 in the United States [
27,
30], and 1 each in India [
32], and Egypt [
31].
Risk of Bias and Study Quality
The risk of bias for the included studies is presented in
Figure 2 and
Table 3 [
29–
35]. Random sequence allocation and allocation concealment were described in all 7 studies [
27,
29–
35]. Five studies were at high risk of blinding participants and personnel [
29–
32,
34], and 2 studies were unclear regarding this domain [
33,
35]. Three studies documented the blinding of outcomes assessment [
29,
30,
33], and the remaining 4 were unclear in this regard [
31,
32,
34,
35]. Additionally, all 7 studies reported a low risk of incomplete outcome data and selective reporting bias [
29–
35]. Further, 5 studies [
30–
34] reported a low risk of other biases, and 2 were unclear [
29,
35] (
Figures 2,
3).
Result of Syntheses
The point prevalence at the end of treatment served as the primary outcome for this review and meta-analysis. Four studies reported the point prevalence at the end of treatment following cognitive behavior therapy [
30–
32,
35]. The pooled analysis indicated that participants in the experimental group (
n=252), who received cognitive behavioral treatment, had a fourfold greater likelihood of tobacco use abstinence compared to the control group (
n=242) (OR, 4.04; 95% CI, 2.73–5.99;
I2=19%;
p<0.00001) (
Figure 4).
Further analyses were conducted at 3-month and 6-month follow-ups to determine the long-term impact and sustained effect of CBT on abstinence rates among tobacco users. The pooled analysis demonstrated a significant effect of CBT in maintaining higher abstinence rates at 3-month follow-up in the experimental group (
n=346) compared to controls (
n=283) (OR, 1.62; 95% CI, 1.11–2.38;
I2=0%;
p=0.01) (
Figure 5). Additionally, data from 6-month follow-ups revealed that CBT significantly improved abstinence rates in the experimental group (
n=523) relative to control conditions (
n=500) (OR, 2.19; 95% CI, 1.59–3.00;
I2=0%;
p<0.00001) (
Figure 6). Unexpectedly, the effectiveness of CBT at maintaining abstinence at 6 months was slightly higher than at the 3-month follow-up but remained lower than at the end of treatment.
Publication bias
Funnel plots were utilized to assess publication bias for the selected outcomes, displaying an approximately symmetrical distribution (
Figure 7). This symmetry suggests that publication bias is unlikely to have significantly influenced the meta-analysis findings.
Discussion
Smoking is widely recognized for its harmful effects and is closely associated with increased morbidity and mortality. In response to these risks, numerous novel non-pharmacological interventions—including telephone counseling [
39], acupuncture [
40], individual [
41] and group behavior therapy [
42], self-help intervention [
39], hypnotherapy [
43], healthcare provider-delivered interventions [
44], exercise interventions [
45], motivational interviewing [
19], and CBT [
20,
30,
46]—have been developed to facilitate smoking cessation, demonstrating promising efficacy. Among these, CBT has emerged as a pivotal psychological intervention specifically targeting smoking cessation [
47]. CBT aims to identify and modify maladaptive thought patterns, promote healthier cognitive processes to manage stress, and subsequently reduce relapse rates among individuals with substance use disorders [
21,
22]. While cognitive therapy focuses primarily on helping individuals develop alternative thought processes and behaviors to alleviate psychological distress [
48], CBT specifically emphasizes increasing awareness of negative interpretations and behavioral patterns that reinforce distorted thinking, empowering individuals to modify these patterns and improve mental well-being [
49].
Notably, global evidence underscores the potential of CBT to facilitate cessation and improve abstinence rates among tobacco users [
25], alcohol, and other illicit substances [
50]. However, these studies exhibit significant methodological heterogeneity, resulting in a lack of consensus regarding CBT’s effectiveness in promoting treatment adherence and sustaining abstinence, particularly among healthy smokers.
This systematic review and meta-analysis aimed to evaluate adherence to CBT and abstinence rates among tobacco users at the end of treatment and at 3-month and 6-month follow-up intervals.
Previous literature has frequently reported significant benefits of CBT in reducing smoking rates and promoting abstinence among smokers, irrespective of intervention format, whether face-to-face [
25,
29,
51–
53], online [
54], or through application-based interventions [
55]. To the best of our knowledge, no prior meta-analysis has systematically pooled the effects of CBT specifically in terms of treatment completion and adherence at 3-month and 6-month follow-up intervals among healthy smokers. Nonetheless, substantial individual studies have supported the effectiveness of CBT on overall smoking cessation, point prevalence, and outcomes at both short-term and long-term follow-ups [
25,
27,
30–
35,
53,
55,
56]. Furthermore, studies indicate that CBT combined with pharmacotherapies has greater efficacy compared to usual care or pharmacotherapy alone for users of tobacco [
57], alcohol, and other illicit drugs [
58]. However, standalone CBT has been noted to be approximately 5 times less effective than when integrated with pharmacotherapy in smoking cessation programs [
58,
59]. The results of our meta-analysis explicitly confirmed CBT’s effectiveness in improving abstinence among tobacco users. Additionally, analyses at 3- and 6-month follow-ups indicated sustained but variable adherence effects of CBT on smoking cessation. The inconsistency in adherence intensity over different time intervals should be explored through multiple determinants, including personalized support mechanisms, accessible complementary resources such as medication or financial assistance [
60], and individual behavioral attributes, notably self-efficacy levels [
61]. Similarly, numerous socio-demographic factors, such as male gender, older age, and higher educational attainment, have been identified as correlates of increased adherence rates [
62].
Previous meta-analyses have supported using various non-pharmacological interventions—including hypnotherapy [
43], competition and incentive-based approaches [
16,
18,
39,
40,
42], telephone-based counseling [
39], motivational counseling [
18], group behavior therapy [
42], and acupuncture and related interventions [
40]—for smoking cessation. CBT approaches aimed at promoting smoking cessation outcomes incorporate cognitive strategies (e.g., learning to manage negative behaviors or urges to smoke), behavioral strategies (e.g., changing habits to avoid temptation), and motivational strategies (e.g., directly confronting adverse health consequences). The U.S. Department of Health and Human Services Guidelines Panel on tobacco treatment identified a strong positive relationship between counseling intensity and successful abstinence [
47]. These findings align with our meta-analysis results, demonstrating CBT’s effectiveness in smoking cessation interventions. However, the meta-analysis indicated that CBT sessions must be frequent and sustained to achieve lasting improvements in abstinence rates. Our analysis showed that the effectiveness of CBT decreased from baseline to follow-up intervals, supporting previous findings that emphasize the necessity for frequent and sustained CBT sessions [
47]. Studies exploring the extended use of CBT have highlighted the importance of booster sessions to maintain CBT’s positive effects on smoking cessation, noting that failure to conduct these additional sessions may diminish long-term abstinence outcomes [
27,
63]. Although the reviewed studies were sufficient in number, their relatively small sample sizes highlighted a high dropout rate and limited long-term adherence to CBT among tobacco users. A substantial dropout rate may lower the observed effect sizes, potentially obscuring CBT’s true impact on abstinence rates over time.
Moreover, previous evidence indicates that adherence to tobacco cessation treatment is crucial for achieving successful long-term abstinence [
64]. Nevertheless, maintaining consistent participation in therapy remains a significant challenge. Strategies such as financial incentives [
65], the use of telehealth services [
66], shared decision-making [
67], and improved treatment availability and affordability [
68] should be implemented to improve adherence to smoking cessation treatment.
Conversely, research emphasizes the necessity of adopting multimodal approaches—combinations of non-pharmacological and pharmacological interventions—to optimize cessation rates and sustain abstinence [
69,
70]. The greatest improvements in abstinence rates occur when multiple smoking cessation interventions are combined with behavioral treatment over an extended period. However, the present meta-analysis specifically addressed the long-term effects of CBT alone on abstinence rates. Further research should investigate the comparative effectiveness of pharmacological versus non-pharmacological therapies.
Strengths and Limitations
This meta-analysis provides robust primary evidence supporting the efficacy of CBT in promoting long-term smoking cessation among healthy smokers. Firstly, given the low heterogeneity observed, a fixed-effects model was employed for data analysis, enhancing the validity and reliability of the presented evidence. Secondly, the inclusion criteria were meticulously defined, encompassing only studies involving healthy smokers who received CBT through face-to-face delivery methods. This rigorous selection approach significantly strengthens the robustness of the findings.
However, several limitations must be considered when interpreting the results. Primarily, the number of RCTs meeting the eligibility criteria was limited, and these studies typically involved relatively small sample sizes, potentially impacting the generalizability of the results. Notably, 3 out of the 7 included studies [
32–
34] did not report sample size calculations, introducing a possible source of bias. Moreover, the inability to assess adherence to smoking cessation facilitated by CBT beyond 12 months, due to the scarcity of eligible studies, highlights a critical gap in the existing evidence and underscores the necessity for further investigation into CBT’s long-term effectiveness. Furthermore, the studies included were conducted in selected regions, potentially limiting the representativeness of findings in broader geographical contexts. To overcome this limitation and ensure generalizability, we recommend conducting larger-scale, multicentric RCTs involving diverse populations, particularly from low-socioeconomic and non-Western settings, with rigorous methodologies to offer more definitive conclusions.
Despite these limitations, this meta-analysis provides compelling initial evidence regarding the effectiveness of CBT in improving adherence and abstinence rates among tobacco users.
Implications for Clinical Practice
Cognitive behavioral interventions have been extensively and effectively utilized to support tobacco cessation efforts. Evidence indicates that behavioral improvements achieved through CBT programs can be sustained at follow-up intervals in intervention groups compared to control groups, underscoring the enduring impact of CBT on smoking cessation. Furthermore, incorporating CBT as an adjunctive therapy alongside other established interventions could help decrease smoking prevalence and reduce the global burden of tobacco-related diseases. Additionally, group CBT as a standalone treatment approach represents a potentially cost-effective strategy that clinicians may adopt in clinical practice [
58].
Recommendations
Future research should prioritize designing and conducting studies with larger sample sizes to evaluate the cost-effectiveness, feasibility, and safety of CBT. Moreover, future investigations should explore the long-term applicability of CBT relative to other pharmacological and non-pharmacological therapies, thereby strengthening its evidence base and facilitating broader clinical adoption. The findings of this review emphasize the necessity of conducting large-scale, multicentric studies involving diverse populations and standardized follow-up periods to rigorously evaluate long-term adherence to CBT and its sustained efficacy as a smoking cessation intervention.
