Does exposure to body odors increase the effect of mindfulness treatment in patients with depressive and social anxiety symptoms?

INTERVENTION: Patients will be screened using the Liebowitz Social Anxiety Scale, the Patient Health Questionnaire, and the Structured Clinical Interview for DSM‐5, based on which they will be allocated to either the social anxiety (Group 1) or depression group (Group 2). Only female patients will be recruited because gender influences the processing of human body odors. Moreover, depressive and social anxiety symptoms are more common among women than men and women have a greater preference for social emotional stimuli compared to men, which could result in greater effects of the body odors on the patients’ depressive or social anxiety symptoms. On the first day of the study, all patients will be asked to complete a demographic questionnaire, the Trait‐State‐Anxiety Inventory (STAI), the Profile of Mood States (POMS), and the State Mindfulness Scale (SMS). After completing the baseline questionnaires, the patients will be randomly allocated to an odor group (happiness, fear or clean air) and start a treatment intervention consisting of mindfulness meditation (more details below). The odors are previously collected from healthy volunteers (see section below). During the intervention, they will be exposed to the odor corresponding to the group to which they have been randomised, while their electrodermal activity and heart rate is measured. Following the intervention, the STAI and POMS will be assessed once more. At the end of the session patients may watch uplifting and/or calming movie clips to restore their pre‐session state. The next day, all patients will complete the STAI and the POMS again. Next, the patients in Group 1 only will be subjected to stress induction, during which they are told that they will have to give a short pre CONDITION: Depressive symptoms and social anxiety symptoms ; Mental and Behavioural Disorders ; Depressive episode, unspecified PRIMARY OUTCOME: ; Group 1:; Anxiety symptoms measured by the Trait‐State Anxiety Inventory (STAI) at baseline, at the end of day 1, at the beginning of day 2, after stress induction and at the end of day 2.; ; Group 2:; Mood state measured by the Profile of Mood States (POMS) at baseline, at the end of day 1, at the beginning of day 2, and at the end of day 2.; SECONDARY OUTCOME: ; Group 1:; 1. Anxiety symptoms measured using the Trait‐State Anxiety Inventory (STAI) at 1‐week follow‐up; 2. Mood state measured using the Profile of Mood States (POMS) at the end of the session on the second day and at 1‐week follow‐up; 3. Social anxiety using the Liebowitz Social Anxiety Scale at baseline and at 1‐week follow‐up; 4. Number of drop‐outs in each odor group measured at the follow‐up online session 1 week later; ; Group 2:; 1. Mood state measured using the Profile of Mood States (POMS) at 1‐week follow‐up; 2. Anxiety symptoms measured using the Trait‐State Anxiety Inventory (STAI) at the end of the session on the second day and at 1‐week follow‐up; 3. Social anxiety using the Liebowitz Social Anxiety Scale at baseline and at 1‐week follow‐up; 4. Number of drop‐outs in each odor group measured at the follow‐up online session 1 week later; INCLUSION CRITERIA: The inclusion criteria for participants with social anxiety symptoms are: 1. Aged between 18 and 35 years 2. Female gender 3. A score over 50 on the Liebowitz Social Anxiety Scale in its self‐report formulation (LSAS‐SR) 4. A confirmation of the disorder during a face‐to‐face interview 5. Normosmic as screened with Sniffin’ Stick test 6. No previous diagnosis of COVID‐19 7. No pregnancy 8. Non‐smokers The inclusion criteria for participants with depressive symptoms are: 1. Aged between 18 and 35 years 2. Female gender 3. A score over 5 on the Patient Health Questionnaire (PHQ‐9) 4. A confirmation of the disorder during a face‐to‐face interview 5. Normosmic as screened with Sniffin’