Evidence-based behaviour change techniques to aid smoking cessation for pregnant women with mental illness: a systematic review

BACKGROUND: Smoking during pregnancy is the leading preventable cause of maternal and infant morbidity and mortality in high income countries, disproportionately affecting women with mental illness. While behavioural smoking cessation interventions are effective for pregnant women and non-pregnant people with mental illness separately, evidence for specific smoking cessation interventions for pregnant women with mental illness is lacking. This review aimed to identify and map BCTs from effective general mental health smoking cessation trials to determine which may be helpful for pregnant women experiencing mental illness. METHODS: A systematic review identified effective smoking cessation RCTs among people with mental illness. MEDLINE, EMBASE, PsycINFO, CINAHL, HMIC and CENTRAL databases were searched through April 2026. BCTs were coded using BCT Taxonomy; those in at least two effective interventions classified as 'promising' and compared against BCTs identified within National Centre for Smoking Cessation Training Standard Treatment Programme for pregnant women. RESULTS: Of 12,403 records, 195 full texts were screened and 16 RCTs met the inclusion criteria. Most interventions combined psychosocial and pharmacological components; motivational interviewing was the most common. Of 39 distinct BCTs identified, 26 were 'promising'. Frequent BCTs included goal setting (1.1), problem solving (1.2), action planning (1.4), social support (unspecified) (3.1), instruction on how to perform the behaviour (4.1) and pharmacological support (11.1). High overlap exists; most promising BCTs for mental health populations are already embedded within the standard UK pregnancy care pathway. CONCLUSIONS: This study shows that behavioural components of effective smoking cessation interventions for people experiencing mental illness align with what is available women accessing NHS smoking in pregnancy cessation services. However, persistently high smoking rates in pregnant women with mental illness suggest that the presence of these techniques alone is insufficient. These findings imply that service improvements should prioritise adapting the delivery of existing BCTs, such as goal setting and problem-solving, to address specific psychological barriers and social contexts of this group to improve engagement and clinical outcomes.