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Positive Events Training to Enhance Positive Emotions in Adolescents With Elevated Depressive Symptoms: An N=1 Trial

Positive Events Training to Enhance Positive Emotions in Adolescents With Elevated Depressive Symptoms: An N=1 Trial

Status
Enrolling by invitation
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07825285
Acronym
iPET N=1
Enrollment
1
Registered
2026-09-17
Start date
2026-10-01
Completion date
2028-12-01
Last updated
2026-09-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Anhedonia, Emotional Distress

Keywords

positive emotions, anhedonia, positive affect regulation, emotional distress, autobiographical thinking

Brief summary

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 youngsters 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, the researchers developed a user-friendly training program translated from basic research findings: Positive Event Training (PET). Through PET, adolescents learn to solidify positive memories and positive plans. This low-threshold program, delivered as a group training at secondary schools, was well received by adolescents in a previous project of our lab (Recalling and Anticipating Specific Positive Events to boost Resilience in Adolescents). In the context of the current study, the PET program, which normally consists of four 1-hour sessions, will be delivered in three individual sessions. The previous project at secondary schools showed that PET leads to heightened positive emotions particularly among youths with elevated depressive tendencies. This indicates that PET can offer increased resilience against depression, especially for vulnerable young individuals. In our current project, the researchers conduct a comprehensive, fine-grained evaluation of the PET program's effectiveness, delivered in an individual format, by collecting intensive data and detailed participant feedback.

Interventions

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). Other Name:

Sponsors

KU Leuven
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE

Intervention model description

single-case experimental design

Eligibility

Sex/Gender
ALL
Age
12 Years to 16 Years
Healthy volunteers
No

Inclusion criteria

* moderate level of baseline depressive symptoms * must be Dutch-speaking

Exclusion criteria

\- /

Design outcomes

Primary

MeasureTime frameDescription
Daily-life positive emotions measured via daily diary items at baseline (adapted from Kirtley et al., 2022)One month (30 days) of daily diaries (3x/day) before the start of the training: Day 1a + all consecutive days until Day 30a (= day before the start of the training)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).
Daily-life positive emotions measured via daily diary items at post-training (adapted from Kirtley et al., 2022)One month (30 days) of daily diaries (3x/day) immediately after the end of the training: Day 1b = the day after the final training day + all consecutive days until Day 30bMean 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).
Daily-life anhedonia measured via daily diary items at baseline (adapted from Bogaert et al., 2023)One month (30 days) of daily diaries (3x/day) before the start of the training: Day 1a + all consecutive days until Day 30a (= day before the start of the training)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).
Daily-life anhedonia measured via daily diary items at post-training (adapted from Bogaert et al., 2023)One month (30 days) of daily diaries (3x/day) immediately after the end of the training: Day 1b = the day after the final training day + all consecutive days until Day 30bMean 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).
Daily-life dampening measured via daily diary items at baseline (adapted from Gérardy et al., in preparation; simplified to better fit target group of adolescents)One month (30 days) of daily diaries (3x/day) before the start of the training: Day 1a + all consecutive days until Day 30a (= day before the start of the training)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).
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)One month (30 days) of daily diaries (3x/day) immediately after the end of the training: Day 1b = the day after the final training day + all consecutive days until Day 30bMean 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).
Daily-life savoring measured via daily diary items at baseline (adapted from Gérardy et al., in preparation; simplified to better fit target group of adolescents)One month (30 days) of daily diaries (3x/day) before the start of the training: Day 1a + all consecutive days until Day 30a (= day before the start of the training)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).
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)One month (30 days) of daily diaries (3x/day) immediately after the end of the training: Day 1b = the day after the final training day + all consecutive days until Day 30bMean 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).
Daily-life emotional distress measured via daily diary items at baseline (derived from Bogaert et al., 2023)One month (30 days) of daily diaries (3x/day) before the start of the training: Day 1a + all consecutive days until Day 30a (= day before the start of the training)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).
Daily-life emotional distress measured via daily diary items at post-training (derived from Bogaert et al., 2023)One month (30 days) of daily diaries (3x/day) immediately after the end of the training: Day 1b = the day after the final training day + all consecutive days until Day 30bMean 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).

Secondary

MeasureTime frameDescription
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 baselineSingle timepoint, participants are invited to complete the survey before the start of the training (= the day before Day 1a, which is the start of the daily diary assessment phase)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).
Autobiographical memory features measured via the Autobiographical Memory (AM) Test (AMT; Raes, Williams, & Hermans, 2009) and single item rating scales per generated event at baselineSingle timepoint, participants are invited to complete the survey before the start of the training (= the day before Day 1a, which is the start of the daily diary assessment phase)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).
Positive Affect subscale of the Positive and Negative Affect Schedule Scales (PANAS; Watson et al., 1988) at baselineSingle timepoint, participants are invited to complete the survey before the start of the training (= the day before Day 1a, which is the start of the daily diary assessment phase)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).
Leuven Anhedonia Scale (LASS, 2nd version; Nelis et al., 2018) at baselineSingle timepoint, participants are invited to complete the survey before the start of the training (= the day before Day 1a, which is the start of the daily diary assessment phase)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).
Dampening measured via the Leuven Exeter Dampening Scale (LEDS, Bogaert et al., 2025) at baselineSingle timepoint, participants are invited to complete the survey before the start of the training (= the day before Day 1a, which is the start of the daily diary assessment phase)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).
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 baselineSingle timepoint, participants are invited to complete the survey before the start of the training (= the day before Day 1a, which is the start of the daily diary assessment phase)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).
Depression, Anxiety, and Stress Scale (DASS-21; Lovibond & Lovibond, 1995) at baselineSingle timepoint, participants are invited to complete the survey before the start of the training (= the day before Day 1a, which is the start of the daily diary assessment phase)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).
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 baselineSingle timepoint, participants are invited to complete the survey before the start of the training (= the day before Day 1a, which is the start of the daily diary assessment phase)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).
Daily-life resilience (general) measured via daily diary item at baselineOne month (30 days) of daily diaries (3x/day) before the start of the training: Day 1a + all consecutive days until Day 30a (= day before the start of the 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).
Daily-life resilience (in response to stress, using positive emotions) measured via daily diary item at baselineOne month (30 days) of daily diaries (3x/day) before the start of the training: Day 1a + all consecutive days until Day 30a (= day before the start of the 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).
Daily-life resilience (in response to stress) measured via daily diary item at baselineOne month (30 days) of daily diaries (3x/day) before the start of the training: Day 1a + all consecutive days until Day 30a (= day before the start of the 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).
Mental wellbeing measured via the Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS; Ikink et al., 2012; Stewart-Brown et al., 2009) at baselineSingle timepoint, participants are invited to complete the survey before the start of the training (= the day before Day 1a, which is the start of the daily diary assessment phase)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).
Persistent negative thinking measured via the Persistent and Intrusive Negative Thoughts Scale (PINTS; Magson et al., 2019; 5 items) at baselineSingle timepoint, participants are invited to complete the survey before the start of the training (= the day before Day 1a, which is the start of the daily diary assessment phase)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).
Common humanity measured via the "Samen mens zijn" scale (Raes & Bogaert, 2025; unpublished) at baselineSingle timepoint, participants are invited to complete the survey before the start of the training (= the day before Day 1a, which is the start of the daily diary assessment phase)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).
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-trainingSingle timepoint, participants are invited to complete the survey immediately after the end of the training (= the day after the final training session or Day 1b)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).
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-trainingSingle timepoint, participants are invited to complete the survey immediately after the end of the training (= the day after the final training session or Day 1b)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).
Positive Affect subscale of the Positive and Negative Affect Schedule Scales (PANAS; Watson et al., 1988) at post-trainingSingle timepoint, participants are invited to complete the survey immediately after the end of the training (= the day after the final training session or Day 1b)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).
Leuven Anhedonia Scale (LASS, 2nd version; Nelis et al., 2018) at post-trainingSingle timepoint, participants are invited to complete the survey immediately after the end of the training (= the day after the final training session or Day 1b)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).
Dampening measured via the Leuven Exeter Dampening Scale (LEDS, Bogaert et al., 2025) at post-trainingSingle timepoint, participants are invited to complete the survey immediately after the end of the training (= the day after the final training session or Day 1b)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).
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-trainingSingle timepoint, participants are invited to complete the survey immediately after the end of the training (= the day after the final training session or Day 1b)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).
Depression, Anxiety, and Stress Scale (DASS-21; Lovibond & Lovibond, 1995) at post-trainingSingle timepoint, participants are invited to complete the survey immediately after the end of the training (= the day after the final training session or Day 1b)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).
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-trainingSingle timepoint, participants are invited to complete the survey immediately after the end of the training (= the day after the final training session or Day 1b)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).
Daily-life resilience (general) measured via daily diary item at post-trainingOne month (30 days) of daily diaries (3x/day) immediately after the end of the training: Day 1b = the day after the final training day + all consecutive days until Day 30bDaily 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).
Daily-life resilience (in response to stress, using positive emotions) measured via daily diary item at post-trainingOne month (30 days) of daily diaries (3x/day) immediately after the end of the training: Day 1b = the day after the final training day + all consecutive days until Day 30bDaily 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).
Daily-life resilience (in response to stress) measured via daily diary item at post-trainingOne month (30 days) of daily diaries (3x/day) immediately after the end of the training: Day 1b = the day after the final training day + all consecutive days until Day 30bDaily 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).
Mental wellbeing measured via the Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS; Ikink et al., 2012; Stewart-Brown et al., 2009) at post-trainingSingle timepoint, participants are invited to complete the survey immediately after the end of the training (= the day after the final training session or Day 1b)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).
Persistent negative thinking measured via the Persistent and Intrusive Negative Thoughts Scale (PINTS; Magson et al., 2019; 5 items) at post-trainingSingle timepoint, participants are invited to complete the survey immediately after the end of the training (= the day after the final training session or Day 1b)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).
Common humanity measured via the "Samen mens zijn" scale (Raes & Bogaert, 2025; unpublished) at post-trainingSingle timepoint, participants are invited to complete the survey immediately after the end of the training (= the day after the final training session or Day 1b)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).

Countries

Belgium

Contacts

PRINCIPAL_INVESTIGATORFilip Raes

KU Leuven

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 18, 2026