Effects of a mental health oriented information campaign on smoking behaviours in young smokers: a randomized trial

Smoking is the most widespread preventable risk factor for poor health worldwide (1). Not only does it increase mortality, it also induces serious morbidity and high healthcare costs for the people who smoke and those around them (2). The effects of smoking on cancer development, respiratory and cardiovascular disease have been known for years. Recently, causal effects of smoking on serious mental illness are becoming more evident (3-5). Substantial converging evidence points to smoking increasing the risk or severity of depression, anxiety, and schizophrenia among others (6-9) Although cigarette smoking has devastating effects, cessation can lead to immediate and longer term relief from both physical (10) and mental health problems (11). Multiple strategies have been developed throughout the years to increase cessation rates and to improve prevention. From alternative nicotine delivery methods like vapes, pouches, or nicotine patches, to counselling, medication, and psychotherapy, several procedures have shown promising results (12, 13). In parallel, public health campaigns and changes in policy have taken place to inform the public about the adverse physical health effects of smoking (14) and to change people’s behaviour respectively. Common strategies include removing all branding from packaging, banning smoking from public places, price increases, and displaying text and pictorial warnings in packaging (15). These efforts, which have largely focused on the detrimental effects of smoking on cancer risk as well as pulmonary and cardiovascular health, are estimated to have contributed to a 5–10% reduction in global smoking rates across age groups (16-21). Nonetheless, many users do not quit, and some even increase their use as a response to health warnings (22). One of the causes of the reduced effectiveness of health warnings is that the effects on physical health happen gradually over time, making smokers perceive them as a long-term threat rather than an immediate concern (23). Thus, reduced threat perception and the promise that smoking cessation can reverse physical ill health in a relatively short time may undermine the urgency of the message. However, the discovery of causal effects of cigarette smoking on short-term mental health offers a new avenue for prevention and cessation strategies (24-26). Recent studies have tested the effectiveness of smoking cessation strategies that incorporate mental health warnings. Evidence suggests that smokers with mental health problems are more susceptible to quit smoking when exposed to mental health warnings (27) compared to physical health warnings. Specifically, motivation to quit smoking is stronger among smokers with a lifetime history of depression and anxiety when exposed to mental health messages compared to physical health messages or no message at all (28). In contrast, among adult smokers without mental health problems, mental health warnings elicit similar motivation to stop smoking as physical health warnings, both being more effective than blank labels (29). These studies further indicate that pre-existing beliefs that smoking is a mood enhancer are more prevalent in those with current psychiatric symptoms and in those with a lifetime history of anxiety or depression than in healthy individuals (28). At the same time, mental health warning labels have been reported to be less effective, less believable, less arousing, less unpleasant, yet more novel than physical health warning labels (30). One proposed strategy to improve the believability and effectiveness of mental health warnings is to provide explanations of the underlying mechanisms through which smoking may adversely affect mental health, such as neuroinflammation or the direct effects of nicotine on brain function (31-33). This approach could be particularly effective among younger smokers, who may be aware of the physical consequences of smoking but less aware of its potential mental health risks. Increasing awareness of these risks may be especially impactful, as younger smokers may be more concerned about and responsive to short-term mental health consequences than to long-term physical outcomes. Moreover, younger smokers have a longer potential lifespan free from smoking-related harm, and might be more likely to smoke due to peer influences and impulsivity. Delivering such information via video allows for more detailed and nuanced explanations of biological mechanisms than are feasible with traditional packaging-based health warnings. Finally, positively framed health messages emphasizing the benefits of quitting rather than the harms of continued smoking, have previously been shown to be an effective communication strategy in the context of smoking-related health outcomes (28, 29, 34). Building upon the available literature, this study aims to examine the effects of mental and physical health warnings, with and without explanations of their underlying mechanisms, on a range of behavioural and psychological outcomes in young adult smokers. This study primarily focusses on the effect that informative, positively-framed, mental health-related videos have on young smokers’ motivation to stop smoking, the effectiveness, and believability of the message. In addition, we assess emotional and cognitive message responses—valence, arousal, novelty, reactance, and perceived understanding—outcomes previously shown to differentiate health warning messages from physical warnings and controls in experimental studies (30). These outcomes inform the development of effective communication strategies for target populations. Understanding which message characteristics most strongly influence young adult smokers’ motivation to change behaviour can guide the design of future public health campaigns and evidence-based policy initiatives.