Italian YOLO: A Web-Based ACT Mental Health Promotion Intervention for University Students (YOLO)

实验性的：Intervention Group

4-weeks web-based interventions

行为的：Italian YOLO

Participants allocated to the experimental group will receive immediate access to the web-based YOLO program during the initial intervention period. They will be asked to complete one module per week, with each module based on the core principles of ACT. The intervention consists of four online modules designed to promote psychological flexibility.

The content of the modules will cover the following topics:

1. Values and committed action
2. Cognitive defusion
3. Acceptance and willingness
4. Mindfulness and observer self.

无干预：Waitlist control

Participants allocated to the waitlist control group will complete the baseline assessment and the initial post-waitlist assessment before receiving access to the YOLO program. During the waiting period, they will not have access to the intervention content. After completing the post-waitlist assessment, they will be granted full access to the same web-based YOLO ACT program as the experimental group.

Depression

The Patient Health Questionnaire-9 (PHQ-9) is used to assess depressive symptoms. The scale includes 9 items, each corresponding to a symptom domain of depression. Each item is rated on a scale from 0 ("Not at all") to 3 ("Nearly every day"), where participants indicate how often they have experienced each symptom during the previous two weeks.

The total PHQ-9 score is calculated by summing all 9 items. Total scores range from 0 to 27. Higher scores indicate greater severity of depressive symptoms. The Italian version of the PHQ-9 has shown adequate psychometric properties in an Italian sample, with a reliability index of .80 and evidence of measurement invariance across age at the scalar level and across sex at the metric level.

Anxiety

The Generalized Anxiety Disorder-7 scale (GAD-7) is used to assess anxiety symptoms. The scale includes 7 items assessing symptoms such as nervousness, uncontrollable worry, difficulty relaxing, restlessness, irritability, and fear that something awful might happen. Each item is rated on a scale from 0 ("Not at all") to 3 ("Nearly every day"), where participants indicate how often they have experienced each symptom during the previous two weeks.

The total GAD-7 score is calculated by summing all 7 items. Total scores range from 0 to 21. Higher scores indicate greater severity of anxiety symptoms. The Italian GAD-7 has shown good psychometric properties in an Italian coronary heart disease sample. Cronbach's alpha was .89 and the composite reliability index was .90. Measurement invariance across gender and age was supported at the scalar level.

Psychological well-being

The Generalized Anxiety Disorder-7 scale (GAD-7) is used to assess anxiety symptoms. The scale includes 7 items assessing symptoms such as nervousness, uncontrollable worry, difficulty relaxing, restlessness, irritability, and fear that something awful might happen. Each item is rated on a scale from 0 ("Not at all") to 3 ("Nearly every day"), where participants indicate how often they have experienced each symptom during the previous two weeks.

The total GAD-7 score is calculated by summing all 7 items. Total scores range from 0 to 21. Higher scores indicate greater severity of anxiety symptoms. The Italian GAD-7 has shown good psychometric properties in an Italian coronary heart disease sample. Cronbach's alpha was .89 and the composite reliability index was .90. Measurement invariance across gender and age was supported at the scalar level.

Psychological flexibility

The Multidimensional Psychological Flexibility Inventory Short Form (MPFI-24) is used to assess psychological flexibility and psychological inflexibility. It includes 12 subscales, with two items assessing each ACT-related process, and yields two higher-order domains: psychological flexibility and psychological inflexibility. Subscale scores are calculated by averaging the two corresponding items. Scores range from 1 to 6, with higher psychological flexibility scores indicating greater flexible responding and higher psychological inflexibility scores indicating greater psychological inflexibility. The Italian MPFI-24 also showed good internal consistency, with reliability coefficients ranging from .71 to .92 across global and subscale scores.

Resilience

The Brief Resilience Scale (BRS) is used to assess participants' perceived ability to recover from stress and adversity. The scale includes 6 items rated on a 5-point scale from 1 ("Strongly disagree") to 5 ("Strongly agree").

The BRS includes both positively and negatively worded items. Negatively worded items are reverse scored before calculating the total score. The total score is calculated by summing the 6 items, with scores ranging from 6 to 30. Higher scores indicate greater perceived resilience.

Purpose in life

The Brief Purpose in Life Measure is used to assess participants' perceived sense of purpose in life. The scale includes 4 items assessing the extent to which participants experience their lives as meaningful and guided by personally significant aims.

Items are rated on a scale from 1 ("Strongly disagree") to 5 ("Strongly agree"). Total scores are calculated by summing the 4 items, with scores ranging from 4 to 20. Higher scores indicate a stronger perceived sense of purpose in life.

Academic self-efficacy

The General Academic Self-Efficacy Scale (GASE) is used to assess students' perceived confidence in their ability to manage academic tasks and demands. The scale includes 5 items rated on a 7-point scale from 1 ("Strongly disagree") to 7 ("Strongly agree").

The total score is calculated by summing the 5 items, with scores ranging from 5 to 35. Higher scores indicate stronger general academic self-efficacy. The GASE has shown good psychometric properties in university student samples. However, no Italian validation of the GASE was identified. Therefore, reliability and validity evidence for the Italian version used in the present study will be examined in the present sample.

Academic performance

The academic performance measure is adapted from the measure used in the YOLO trial. It is used to assess students perceived academic functioning. Items are rated on a 10-point scale from 1 ("Performing at your worst") to 10 ("Performing at your best"), with an additional "Not applicable" option where relevant.

Scores are calculated by averaging the valid items. Higher scores indicate better perceived academic performance and academic functioning. The total score reflects the mean level of perceived academic performance across the retained academic functioning items.

Caregiving responsibilities

The Caregiving Responsibilities subscale of the Young Carers of Parents Inventory-Revised (YCOPI-R) is used to assess caregiving responsibilities among students. The subscale includes 7 items assessing the extent to which participants feel responsible for helping or caring for a parent or family member, including household, practical, and care-related responsibilities. Each item is rated on a 5-point scale from 0 ("Strongly disagree") to 4 ("Strongly agree").

The score is calculated by averaging the 7 items. Scores range from 0 to 4, with higher scores indicating greater caregiving responsibilities. The Caregiving Responsibilities subscale of the Italian YCOPI-R has shown good internal consistency, with Cronbach's alpha = .80.