Promoting Positive Emotions in Adolescents Using Positive Events Training: An Indicated Approach (iPET)

Promoting Positive Emotions in Adolescents Using Positive Event Training: An Indicated Approach (iPET)

Research shows that high positive emotionality is an essential ingredient in building resilience in youngsters, especially those with a vulnerability to develop depressive symptomatology. It may empower them against actual depression and its various long-term adverse outcomes. One way to achieve positive emotions is via the recollection and anticipation of specific positive events. Therefore, to cultivate positive emotions in young people, a user-friendly group training program was developed, translated from basic research findings: Positive Event Training (PET). Through PET, adolescents learn to solidify positive memories and positive plans for the future. In this project, a comprehensive evaluation of PET's efficacy is conducted using a robust methodology with vulnerable youth.

Study Overview

• Status: Not yet recruiting
• Conditions: Anhedonia; Emotional Distress
• Intervention / Treatment: Behavioral: Positive Events Training (PET)

• Study Type: Interventional
• Enrollment (Estimated): 36
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Filip Raes; Phone Number: +32 16 32 58 92; Email: filip.raes@kuleuven.be
• Study Contact Backup: Name: Liesbeth Bogaert; Email: liesbeth.bogaert@kuleuven.be

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• 12-16 years (age)
• moderate level of baseline depressive symptoms Exclusion Criteria: /

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Positive Events Training (PET)	Behavioral: Positive Events Training (PET); Positive Event Training or PET is a group-based training program combining Memory Specificity Training (MEST; Raes, 2007) and Future Event Specificity Training (FEST; Dutch version of Hallford et al. (2020): Changing the Future: An initial test of Future Specificity Training).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Daily-life positive emotions measured via daily diary items at post-training (adapted from Kirtley et al., 2022)	Mean value of four daily diary items (i.e., "How relaxed, content, enthusiast, good do you feel?"), rated on a 0 ("not at all") to 100 ("a lot") rating scale. Higher values represent, higher levels of positive emotions (min = 0, max = 100).	Measured via nine days of daily diaries (2x/day) immediately after the training (i.e., four weeks after the baseline assessment)
Daily-life positive emotions measured via daily diary items at follow-up (adapted from Kirtley et al., 2022)	Mean value of four daily diary items (i.e., "How relaxed, content, enthusiast, good do you feel?"), rated on a 0 ("not at all") to 100 ("a lot") rating scale. Higher values represent, higher levels of positive emotions (min = 0, max = 100).	Measured via nine days of daily diaries (2x/day) after two/three months of follow-up after the post-training assessment
Daily-life anhedonia measured via daily diary items at post-training (adapted from Bogaert et al., 2023)	Mean value of three daily diary items tapping into difficulties experiencing consummatory pleasure, anticipatory pleasure and motivational difficulties using a 0-100 Likert scale (0 = "not at all", 100 = "a lot"; items: "To what extent did you find it difficult to enjoy yourself?"; "To what extent did you look forward to doing enjoyable things? (reverse-scored), "Conditional: if 0-50 ("not at all - neutral"): Was this because there really weren't any enjoyable things to look forward to, or because they were there but you couldn't really look forward to them?; "How happy did you feel?" (reverse-scored)). Higher score reflects higher levels of anhedonia (min = 0, max = 100).	Measured via nine days of daily diaries (2x/day) immediately after the end of the training (i.e., four weeks after the baseline assessment)
Daily-life anhedonia measured via daily diary items at follow-up (adapted from Bogaert et al., 2023)	Mean value of three daily diary items tapping into difficulties experiencing consummatory pleasure, anticipatory pleasure and motivational difficulties using a 0-100 Likert scale (0 = "not at all", 100 = "a lot"; items: "To what extent did you find it difficult to enjoy yourself?"; "To what extent did you look forward to doing enjoyable things? (reverse-scored), "Conditional: if 0-50 ("not at all - neutral"): Was this because there really weren't any enjoyable things to look forward to, or because they were there but you couldn't really look forward to them?; "How happy did you feel?" (reverse-scored)). Higher score reflects higher levels of anhedonia (min = 0, max = 100).	Measured via nine days of daily diaries (2x/day) after two/three months of follow-up after the post-training assessment
Daily-life dampening measured via daily diary items at post-training (adapted from Gérardy et al., in preparation; simplified to better fit target group of adolescents)	Mean value of four daily life items to measure mental strategies to reduce the intensity and/or frequency of positive emotions, using a 0-100 Likert scale (0 = "not at all", 100 = "a lot"; items: "To what extent did you think, "This pleasant feeling won't last"?"; "To what extent did you think, "I don't deserve to feel good"?"; To what extent did you think, "Something might go wrong that will make my good/pleasant feeling go away"?; "To what extent did you think about how difficult it would be if your good/pleasant feeling suddenly disappeared?"). Higher score reflects higher levels of dampening (min = 0, max = 100).	Measured via nine days of daily diaries (2x/day) immediately after the end of the training (i.e., four weeks after the baseline assessment)
Daily-life dampening measured via daily diary items at follow-up (adapted from Gérardy et al., in preparation; simplified to better fit target group of adolescents)	Mean value of four daily life items to measure mental strategies to reduce the intensity and/or frequency of positive emotions, using a 0-100 Likert scale (0 = "not at all", 100 = "a lot"; items: "To what extent did you think, "This pleasant feeling won't last"?"; "To what extent did you think, "I don't deserve to feel good"?"; To what extent did you think, "Something might go wrong that will make my good/pleasant feeling go away"?; "To what extent did you think about how difficult it would be if your good/pleasant feeling suddenly disappeared?"). Higher score reflects higher levels of dampening (min = 0, max = 100).	Measured via nine days of daily diaries (2x/day) after two/three months of follow-up after the post-training assessment
Daily-life savoring measured via daily diary items at post-training (adapted from Gérardy et al., in preparation; simplified to better fit target group of adolescents)	Mean value of two daily life items tapping into the the engagement in attending to, appreciating and enhancing positive experiences, using a 0-100 Likert scale (0 = "not at all", 100 = "a lot"; items: "To what extent did you allow the good/pleasant feeling to be there and simply let it be?", "To what extent did you try to really focus your attention on the good/pleasant feeling in order to fully experience it and truly enjoy it?"). Higher scores reflect a higher tendency to savor (min = 0, max = 100).	Measured via nine days of daily diaries (2x/day) immediately after the end of the training (i.e., four weeks after the baseline assessment)
Daily-life savoring measured via daily diary items at follow-up (adapted from Gérardy et al., in preparation; simplified to better fit target group of adolescents)	Mean value of two daily diary items tapping into the the engagement in attending to, appreciating and enhancing positive experiences, using a 0-100 Likert scale (0 = "not at all", 100 = "a lot"; items: "To what extent did you allow the good/pleasant feeling to be there and simply let it be?", "To what extent did you try to really focus your attention on the good/pleasant feeling in order to fully experience it and truly enjoy it?"). Higher scores reflect a higher tendency to savor (min = 0, max = 100).	Measured via nine days of daily diaries (2x/day) after two/three months of follow-up after the post-training assessment
Daily-life emotional distress measured via daily diary items at post-training (derived from Bogaert et al., 2023)	Mean value of three daily diary items to measure anxiety, stress and depressed feelings, using a 0-100 Likert scale (0 = "not at all", 100 = "a lot"; items: "How anxious did you feel?"; "How depressed (down) did you feel?"; "How stressed did you feel?"). A higher score reflects higher levels of emotional distress (min = 0, max = 100).	Measured via nine days of daily diaries (2x/day) immediately after the end of the training (i.e., four weeks after the baseline assessment)
Daily-life emotional distress measured via daily diary items at follow-up (derived from Bogaert et al., 2023)	Mean value of three daily diary items to measure anxiety, stress and depressed feelings, using a 0-100 Likert scale (0 = "not at all", 100 = "a lot"; items: "How anxious did you feel?"; "How depressed (down) did you feel?"; "How stressed did you feel?"). A higher score reflects higher levels of emotional distress (min = 0, max = 100).	Measured via nine days of daily diaries (2x/day) after two/three months of follow-up after the post-training assessment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Episodic future thinking features measured via the Episodic Future Thinking Test (EFT-T; Hallford et al., 2019), and single item rating scales per generated event at post-training	8 cue words in response to which a positive future event is generated, accompanied with single-item rating scales ranging from 1 (not at all) to 9 (very much). In line with the study of Hallford, Yeow, et al. (2020), participants rate the index of detail (IoD), mental imagery (MI), anticipated (AdP) and anticipatory pleasure (AyP), and perceived control (PC) and perceived likelihood of occurrence (PLO) associated with the generated future events on the EFT-T. Higher scores reflect higher levels of the feature of interest (min = 8; max = 72).	Measured immediately after the end of the training (i.e., four weeks after the baseline assessment)
Episodic future thinking features measured via the Episodic Future Thinking Test (EFT-T; Hallford et al., 2019), and single item rating scales per generated event at follow-up	8 cue words in response to which a positive future event is generated, accompanied with single-item rating scales ranging from 1 (not at all) to 9 (very much). In line with the study of Hallford, Yeow, et al. (2020), participants rate the index of detail (IoD), mental imagery (MI), anticipated (AdP) and anticipatory pleasure (AyP), and perceived control (PC) and perceived likelihood of occurrence (PLO) associated with the generated future events on the EFT-T. Higher scores reflect higher levels of the feature of interest (min = 8; max = 72).	Measured after two/three months of follow-up after the post-training assessment
Autobiographical memory features measured via the Autobiographical Memory (AM) Test (AMT; Raes, Williams, & Hermans, 2009) and single item rating scales per generated event at post-training	8 cue words in response to which a positive past event is recalled, accompanied with single-item rating scales ranging from 1 (not at all) to 9 (very much). Participants rate the index of detail (IoD), mental imagery (MI), felt and remembered pleasure (FP and RP), associated with the recalled past events on the AMT. Higher scores reflect higher levels of the feature of interest (min = 8; max = 72).	Measured via self-report scales immediately after the end of the training (i.e., four weeks after the baseline assessment)
Autobiographical memory features measured via the Autobiographical Memory (AM) Test (AMT; Raes, Williams, & Hermans, 2009) and single item rating scales per generated event at follow-up	8 cue words in response to which a positive past event is recalled, accompanied with single-item rating scales ranging from 1 (not at all) to 9 (very much). Participants rate the index of detail (IoD), mental imagery (MI), felt and remembered pleasure (FP and RP), associated with the recalled past events on the AMT. Higher scores reflect higher levels of the feature of interest (min = 8; max = 72).	Measured after two/three months of follow-up after the post-training assessment
Positive Affect subscale of the Positive and Negative Affect Schedule Scales (PANAS; Watson et al., 1988) at post-training	Positive affect will be assessed via the Positive Affect subscale of the Positive and Negative Affect Schedule Scales (PANAS; Engelen et al., 2006; Watson et al., 1988). The extent to which 10 positive feelings (e.g., "enthusiastic") were experienced is rated on a 5-point scale ranging from 1 (rarely) to 5 (very often), with higher scores reflecting higher positive affect (min = 10, max = 50).	Measured immediately after the end of the training (i.e., four weeks after the baseline assessment)
Positive Affect subscale of the Positive and Negative Affect Schedule Scales (PANAS; Watson et al., 1988) at follow-up	Positive affect will be assessed via the Positive Affect subscale of the Positive and Negative Affect Schedule Scales (PANAS; Engelen et al., 2006; Watson et al., 1988). The extent to which 10 positive feelings (e.g., "enthusiastic") were experienced is rated on a 5-point scale ranging from 1 (rarely) to 5 (very often), with higher scores reflecting higher positive affect (min = 10, max = 50).	Measured via self-report scales after two/three months of follow-up after the post-training assessment
Leuven Anhedonia Scale (LASS, 2nd version; Nelis et al., 2018) at post-training	12 items rated on a 1-5 Likert scale (1 = "This is completely incorrect for me.", 5 = "This is completely correct to me"). A higher total score reflects higher levels of anhedonia (min = 12, max = 60).	Measured immediately after the end of the training (i.e., four weeks after the baseline assessment)
Leuven Anhedonia Scale (LASS, 2nd version; Nelis et al., 2018) at follow-up	12 items rated on a 1-5 Likert scale (1 = "This is completely incorrect for me.", 5 = "This is completely correct to me"). A higher total score reflects higher levels of anhedonia (min = 12, max = 60).	Measured via self-report scales after two/three months of follow-up after the post-training assessment
Dampening measured via the Leuven Exeter Dampening Scale (LEDS, Bogaert et al., 2025) at post-training	The Leuven Exeter Dampening Scale (LEDS, Bogaert et al., 2025) consists of 13 items rated on a 5-point scale ranging from 1 (not at all) to 5 (very often). A higher score reflects a higher dampening tendency (min = 13, max = 65).	Measured immediately after the end of the training (i.e., four weeks after the baseline assessment)
Dampening measured via the Leuven Exeter Dampening Scale (LEDS, Bogaert et al., 2025) at follow-up	The Leuven Exeter Dampening Scale (LEDS, Bogaert et al., 2025) consists of 13 items rated on a 5-point scale ranging from 1 (not at all) to 5 (very often). A higher score reflects a higher dampening tendency (min = 13, max = 65).	Measured after two/three months of follow-up after the post-training assessment
Savoring measured via the Savoring Subscale of the Four-Factor Model of the Abridged Ways Of Savoring Checklist (WOSC) in Response to Everyday Events (Original scale Bryant and Vernoff, 2007; Four-Factor Model Chadwick, 2012) at post-training	The 10 savoring items of the abridged Ways of Savoring Checklist for Adolescents (not yet validated in Dutch) taps into diverse savoring strategies (WOSC; Chadwick, 2012). Items (e.g., "I looked for other people to share it with") are rated on a 7-point scale ranging from 1 (totally disagree) to 7 (totally agree). Higher scores reflect higher levels of engagement in the respective emotion regulation strategy (min = 10, max = 70).	Measured immediately after the end of the training (i.e., four weeks after the baseline assessment)
Savoring measured via the Savoring Subscale of the Four-Factor Model of the Abridged Ways Of Savoring Checklist (WOSC) in Response to Everyday Events (Original scale Bryant and Vernoff, 2007; Four-Factor Model Chadwick, 2012) at follow-up	The 10 savoring items of the abridged Ways of Savoring Checklist for Adolescents (not yet validated in Dutch) taps into diverse savoring strategies (WOSC; Chadwick, 2012). Items (e.g., "I looked for other people to share it with") are rated on a 7-point scale ranging from 1 (totally disagree) to 7 (totally agree). Higher scores reflect higher levels of engagement in the respective emotion regulation strategy (min = 10, max = 70).	Measured after two/three months of follow-up after the post-training assessment
Depression, Anxiety, and Stress Scale (DASS-21; Lovibond & Lovibond, 1995) at post-training	21 items, rated on a 0-3 Likert scale (0 = "Not at all applicable", 3 = "Almost always applicable"). Higher total (subscale) scores reflect higher levels of emotional distress (depressive symptoms, anxious symptoms and stress; min = 0, max = 63).	Measured immediately after the end of the training (i.e., four weeks after the baseline assessment)
Depression, Anxiety, and Stress Scale (DASS-21; Lovibond & Lovibond, 1995) at follow-up	21 items, rated on a 0-3 Likert scale (0 = "Not at all applicable", 3 = "Almost always applicable"). Higher total (subscale) scores reflect higher levels of emotional distress (depressive symptoms, anxious symptoms and stress; min = 0, max = 63).	Measured via self-report scales after two/three months of follow-up after the post-training assessment
Resilience assessed via the short version of the Connor-Davidson Resilience Scale (CD-RISC; Campbell-Sills & Stein, 2007; Connor & Davidson, 2003; translated into Dutch by Danhof-Pont & Schrier, 2006, 2010) at post-training	Statements of the Connor-Davidson Resilience Scale (10 items; e.g., "I am able to adapt to change") are rated on a 5-point scale ranging from 1 (not at all) to 5 (very often), with higher scores reflecting higher levels of resilience (min = 10, max = 50).	Measured immediately after the end of the training (i.e., four weeks after the baseline assessment)
Daily-life resilience (general) measured via daily diary item at post-training	Daily diary item rated on a 0-100 Likert (0 = not at all; 100 = a lot), with higher scores reflecting higher daily-life resilience (item: "To what extent did you feel that you were able to handle many things at the same time?", adapted from Martinez-Corts et al., 2015).	Measured immediately after the end of the training (i.e., four weeks after the baseline assessment)
Daily-life resilience (in response to stress) measured via daily diary item at post-training	Daily diary item rated on a 0-100 Likert (0 = not at all; 100 = a lot), with higher scores reflecting higher daily-life resilience (item: "To what extent were you able to cope easily with those feelings of stress?", adapted from Brogly et al., 2024).	Measured immediately after the end of the training (i.e., four weeks after the baseline assessment)
Daily-life resilience (in response to stress, using positive emotions) measured via daily diary item at post-training	Daily diary item rated on a 0-100 Likert (0 = not at all; 100 = a lot), with higher scores reflecting higher daily-life resilience (item: "To what extent did you try to think of something pleasant from the past or the future to cope with that stress?", new item).	Measured immediately after the end of the training (i.e., four weeks after the baseline assessment)
Resilience assessed via the short version of the Connor-Davidson Resilience Scale (CD-RISC; Campbell-Sills & Stein, 2007; Connor & Davidson, 2003; translated into Dutch by Danhof-Pont & Schrier, 2006, 2010) at follow-up	Statements of the Connor-Davidson Resilience Scale (10 items; e.g., "I am able to adapt to change") are rated on a 5-point scale ranging from 1 (not at all) to 5 (very often), with higher scores reflecting higher levels of resilience (min = 10, max = 50).	Measured after two/three months of follow-up after the post-training assessment
Daily-life resilience (general) measured via daily diary item at follow-up	Daily diary item rated on a 0-100 Likert (0 = not at all; 100 = a lot), with higher scores reflecting higher daily-life resilience (item: "To what extent did you feel that you were able to handle many things at the same time?", adapted from Martinez-Corts et al., 2015).	Measured after two/three months of follow-up after the post-training assessment
Daily-life resilience (in response to stress) measured via daily diary item at follow-up	Daily diary item rated on a 0-100 Likert (0 = not at all; 100 = a lot), with higher scores reflecting higher daily-life resilience (item: "To what extent were you able to cope easily with those feelings of stress?", adapted from Brogly et al., 2024).	Measured after two/three months of follow-up after the post-training assessment
Daily-life resilience (in response to stress, using positive emotions) measured via daily diary item at follow-up	Daily diary item rated on a 0-100 Likert (0 = not at all; 100 = a lot), with higher scores reflecting higher daily-life resilience (item: "To what extent did you try to think of something pleasant from the past or the future to cope with that stress?", new item).	Measured after two/three months of follow-up after the post-training assessment
Mental wellbeing measured via the Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS; Ikink et al., 2012; Stewart-Brown et al., 2009) at post-training	This self-report scale comprises 7 statements (e.g., "I have been feeling relaxed") rated on a 5-point scale ranging from 1 (never) to 5 (always). Higher scores indicate higher self-reported wellbeing (min = 7, max =35).	Measured immediately after the end of the training (i.e., four weeks after the baseline assessment)
Mental wellbeing measured via the Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS; Ikink et al., 2012; Stewart-Brown et al., 2009) at follow-up	This self-report scale comprises 7 statements (e.g., "I have been feeling relaxed") rated on a 5-point scale ranging from 1 (never) to 5 (always). Higher scores indicate higher self-reported wellbeing (min = 7, max =35).	Measured after two/three months of follow-up after the post-training assessment
Persistent negative thinking measured via the Persistent and Intrusive Negative Thoughts Scale (PINTS; Magson et al., 2019; 5 items) at post-training	This is a 5-item scale measuring the core characteristics of repetitive negative thinking (Magson et al., 2019). The items are answered on a 5-point frequency scale ranging from never (1) to almost always (5). A higher score reflect higher levels of persisitent negative thinking (min = 5, max = 25).	Measured immediately after the end of the training (i.e., four weeks after the baseline assessment)
Persistent negative thinking measured via the Persistent and Intrusive Negative Thoughts Scale (PINTS; Magson et al., 2019; 5 items) at follow-up	This is a 5-item scale measuring the core characteristics of repetitive negative thinking (Magson et al., 2019). The items are answered on a 5-point frequency scale ranging from never (1) to almost always (5). A higher score reflect higher levels of persisitent negative thinking (min = 5, max = 25).	Measured after two/three months of follow-up after the post-training assessment
Common humanity measured via the "Samen mens zijn" scale (Raes & Bogaert, 2025; unpublished) at post-training	Self-report scale consisting of 5 items (e.g., "When I go through difficult things, I realize that others also experience tough moments sometimes, just like I do."), rated on a Likertscale from 1 (never or almost never) to 5 (almost always). A higher score reflects higher levels of common humanity (min = 5, max = 25).	Measured immediately after the end of the training (i.e., four weeks after the end of the baseline assessment)
Common humanity measured via the "Samen mens zijn" scale (Raes & Bogaert, 2025; unpublished) at follow-up	Self-report scale consisting of 5 items (e.g., "When I go through difficult things, I realize that others also experience tough moments sometimes, just like I do."), rated on a Likertscale from 1 (never or almost never) to 5 (almost always). A higher score reflects higher levels of common humanity (min = 5, max = 25).	Measured after two/three months of follow-up after the post-training assessment

Other Outcome Measures

Outcome Measure	Time Frame
Open questions measuring the engagement with the training material, implementation in daily life and general experiences related to the training	Measured after the training (i.e., 4 weeks after the end of the baseline assessment) and at follow-up (i.e., two/three months after the post-training assessment)

Collaborators and Investigators

• Sponsor: KU Leuven
• Collaborators: Research Foundation - Flanders (Fonds Wetenschappelijk Onderzoek)
• Investigators: Principal Investigator: Filip Raes, KU Leuven

Study record dates

Study Major Dates

• Study Start (Estimated): December 1, 2025
• Primary Completion (Estimated): January 1, 2027
• Study Completion (Estimated): January 1, 2027

Study Registration Dates

• First Submitted: November 21, 2025
• First Submitted That Met QC Criteria: December 3, 2025
• First Posted (Actual): December 17, 2025

Study Record Updates

• Last Update Posted (Actual): December 17, 2025
• Last Update Submitted That Met QC Criteria: December 3, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: anhedonia; emotional distress; positive emotions; positive affect regulation; autobiographical thinking
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neurobehavioral Manifestations; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Anhedonia
• Other Study ID Numbers: G051625N

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Data can only be accessed by the involved researchers. Anonymized data can be made available at the end of the study, in line with the data management plan and taking into account the faculties' requirements and ethical principles.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No