Cytisine for Smoking Cessation

Inclusion Criteria:

• Aged 18-65 years;

• Have TUD assessed by structured clinical interview for DSM-5;

• Have past year AUD (active) assessed by structured clinical interview for DSM-5;

• Report daily cigarette consumption in past month and expired carbon monoxide (CO)measurement ≥10ppm at screening;

• Have Fagerstrom Test of Nicotine Dependence (FTND55) score ≥4;

• Have motivation to quit within 30 days i.e. Contemplation Ladder56 score ≥7;

• Be willing and able to comply with all study procedural and assessment demands;

• Be able to provide voluntary written informed consent.

Exclusion Criteria:

• Report prolonged smoking abstinence in the past month preceding screening;

• Be using other smoking cessation aids

• Enrolled in another smoking cessation program

• Be pregnant, breastfeeding, or intending to become pregnant or breastfeed;

• Exhibit suicidal thoughts or behavior in the past month;

• Enrolled in another study which would interfere with study procedures or represent apotential risk to the participant

• Have a serious unstable psychiatric or medical condition preventing participation inthe trial. This includes some forms of schizophrenia, ischemic heart disease, heartfailure, arterial hypertension (systolic BP above 150; diastolic BP above 100),cerebrovascular diseases, occlusion of blood vessels, kidney and/or liver disease,hyperthyroidism, ulcer, diabetes, Chromaffin tumours of the adrenal medulla, andgastroesophageal reflux disease (GERD)