The number of people who smoke, have concurrent depression and that seek treatment for smoking cessation has increased in recent years. This implies the need to design intensive and specific interventions that target this issue. In depression treatment, behavioural activation is one of the psychological interventions whose characteristics of brevity, flexibility and efficiency make it an ideal candidate to be included as part of smoking cessation treatment, especially when smokers have depressive symptoms. The aims of the present trial are: 1) to assess the efficacy (abstinence rates) of a psychological smoking cessation treatment with elements from behavioural activation for managing depressed mood (a randomized control trial with three groups: standard cognitive-behavioural smoking cessation treatment, standard cognitive-behavioural smoking cessation treatment plus behavioural activation, and a control group of delayed treatment) at the end of treatment, and at 3-, 6-, and 12-months follow-ups; and 2) to assess whether the applied cognitive-behavioural smoking cessation treatment plus behavioural activation improves depressed mood at the end of treatment and 3-, 6, 12-months follow-ups.

In recent years there has been a great interest in analyzing the relationship between smoking and depression due to the high smoking rates in this population. Smokers with depression are more likely to smoke heavily, show greater tobacco dependence, suffer more severe withdrawal, experience lower quit rates and have more relapse than smokers without depression. Some studies propose the inclusion of behavioural activation techniques to standard cognitive-behavioural therapy for quitting smoking, arguing that the loss of the ability to experience pleasure in response to daily activities after quitting smoking is a significant barrier to achieving and maintaining abstinence. With this type of intervention, the exposure to positive reinforcers alternative to cigarettes increases and the resulting distress of withdrawal syndrome it is also reduced. Therefore, behavioural activation may improve smoking abstinence rates and depressive symptomatology. This project aims to assess the effectiveness of a psychological intervention for smoking cessation with components of behavioural activation for managing depressed mood. We will use a single blind controlled randomized design. Two hundred and fifty daily (≥ 10 cigarettes/day) smokers will be randomized to one of three conditions: 1) standard cognitive-behavioural smoking cessation treatment (n=100); 2) standard cognitive-behavioural smoking cessation treatment plus behavioural activation (n=100); or 3) a control group of three months delayed treatment (n=50). Both active treatments will be administered in eight weekly 60 minute sessions. The primary outcomes will be carbon monoxide (CO) verified at 24-hours point prevalence abstinence at the end of the treatment, a 7-day point prevalence abstinence at 3 months follow-up, a 30-days point prevalence abstinence at 6-, and 12-months follow-ups; and depressive symptomatology through BDI-II and Hamilton Depression Rating Scale scores at the end of treatment, and at 3-, 6-, and 12-months follow-ups. Additional aims include assessing others activation-related variables, craving, self-efficacy and withdrawal syndrome. This randomized controlled trial will be the first trial of Behavioural Activation and Smoking Cessation psychological treatment in a Spanish sample of seeking treatment smokers.

Inclusion Criteria:

• 18 years of age or older who smoke at least 10 cigarettes per day
• Desire to participate voluntarily in the treatment offered to quit smoking
• Correctly fill out all the pretreatment assessment questionnaires
• Be able to provide written informed consent

Exclusion Criteria:

• To have a diagnosis of a severe mental disorder (bipolar disorder and / or psychotic disorder)
• To have a substance use disorder (alcohol, cannabis, cocaine, heroin), different from a tobacco use disorder
• To smoke rolling snuff, cigars, little cigars or other tobacco products
• To have participated in an effective psychological treatment to quit smoking during the previous 12 months
• To have received other effective pharmacological treatment to quit smoking in the previous 12 months (nicotine gum or patches, bupropion, varenicline)
• To have a physical pathology involving life threatening risks for the person who would require immediate intervention in individual format (eg. Recent myocardial infarction, pneumothorax, etc.)