Booth, R. W., Erhan, K., Erkocaoğlan, O., Kuşpınar, H., & Yaldırak, K. (2025). The best possible self task has direct effects on expectancies and mood, and an indirect effect on anxiety symptom severity. Emotion, 25(4), 964–971. https://doi.org/10.1037/emo0001481
Key Takeaways
- Focus: The study investigates how a positive psychology exercise called the Best Possible Self (BPS) task influences people’s expectations about the future (optimism), their mood, and anxiety symptoms.
- Method: A large randomized controlled trial was conducted with 240 university students who either completed the BPS task or a control writing task about a typical day, with measures taken before, immediately after, and one week later.
- Findings: The BPS task significantly improved positive expectations about the future and positive mood right after the intervention; improvements in positive expectations lasted a week and also indirectly reduced anxiety symptoms at follow-up.
- Implications: The findings suggest that the BPS task can be used to increase optimism and mood quickly, and these changes in optimism may help reduce anxiety symptoms, highlighting its potential use in mental health interventions.
Rationale
The study focuses on the psychological concept of expectancies, which refers to the beliefs or predictions people hold about what will happen to them in the future.
This includes both positive expectancies (hope or optimism about good things happening) and negative expectancies (pessimism or fear about bad outcomes).
Closely tied to this is mood, which describes the general emotional state a person is in, such as feeling happy or sad.
Research in positive psychology has identified the Best Possible Self (BPS) task as a simple and effective intervention that encourages people to imagine a future where everything has gone as well as possible, and they have achieved their goals.
This task has been found to increase optimism and improve mood, which are both important for psychological wellbeing.
However, despite many studies showing that BPS helps, there remains uncertainty about how it works: Does it primarily improve expectancies (making people more optimistic), which then improves mood?
Or does it primarily improve mood, which then leads to better expectancies?
Also, while its effects on optimism and mood are well-documented, less is known about whether it can reduce negative symptoms like anxiety or depression, and how expectancies and mood changes might mediate such effects.
Previous studies on BPS have often been small and inconsistent, and many have focused on either mood or optimism but rarely explored both, or their effects on anxiety and depression symptoms.
Thus, this study addresses several important gaps:
It uses a large, well-powered sample; it examines both positive and negative expectancies and mood; it investigates mediation between expectancies and mood changes; and it looks at symptom severity of anxiety and depression as outcomes.
Understanding these mechanisms is crucial for psychology because it informs how simple interventions like BPS can be best used to promote mental health.
If we know whether changing expectancies or mood is key, we can tailor treatments or combine BPS with other therapies to maximize benefits.
Also, identifying any impact on anxiety or depression symptoms could open doors to new low-cost, accessible mental health interventions, especially important in university settings or for people who may not seek traditional therapy.
Method
This was a randomized controlled trial (RCT) with two groups: the experimental group completing the Best Possible Self task, and the control group writing about a typical day.
Participants completed assessments before the intervention (pretest), immediately after (posttest), and about one week later (follow-up).
This design allowed the researchers to test immediate and short-term effects of the intervention.
Sample
- Size: 240 university students
- Demographics: Mostly Turkish students, average age about 22, 151 women, 87 men, 2 others
- Some participants had diagnosed anxiety (18) or depression (8) but participants with ADHD or OCD were excluded.
- Follow-up data were collected from 202 participants.
Variables
- Independent variable: Type of writing task (Best Possible Self vs. Typical Day)
- Dependent variables:
- Positive and negative expectancies about the future
- Positive and negative mood
- Severity of anxiety symptoms
- Severity of depressive symptoms
Procedure
- Pretest: Participants completed measures of expectancies, mood, anxiety, and depression.
- Intervention:
- BPS group: Imagine and write for 15 minutes about their best possible future self, then vividly imagine that future for 5 minutes.
- Control group: Write about a typical day and imagine it.
- Posttest: Immediately after writing, participants completed the expectancies and mood measures again.
- Follow-up: 6-8 days later, participants repeated all measures (expectancies, mood, anxiety, depression).
Measures
- Expectancies: A 24-item scale measuring how likely participants thought positive and negative future events were to happen to them.
- Mood: Positive and Negative Affect Schedule (PANAS) measuring current feelings of positive and negative mood.
- Anxiety: Beck Anxiety Inventory (BAI), assessing recent anxiety symptoms.
- Depression: Beck Depression Inventory (BDI), assessing recent depressive symptoms.
All measures were chosen for their reliability and validity in capturing expectancies, mood, and symptoms relevant to the study aims.
Statistical Analyses
- The study used analysis of covariance (ANCOVA) to compare groups at posttest and follow-up, controlling for pretest scores to account for initial differences.
- Mediation analyses tested whether changes in expectancies explained changes in mood or symptoms (and vice versa).
- Outliers were excluded to ensure robust results, and multiple imputation was used to handle missing follow-up data.
Results
- The BPS group showed significantly higher positive expectancies and lower negative expectancies than the control group immediately after the task.
- The BPS group had higher positive mood and slightly lower negative mood at posttest.
- Mediation analyses suggested the effect of BPS on positive mood was partly explained by increases in positive expectancies, and the effect on negative mood was partly explained by decreases in negative expectancies.
- At follow-up, the BPS group still had higher positive expectancies but no significant mood differences compared to the control.
- Anxiety symptoms were significantly lower in the BPS group at follow-up, and this effect was mediated by positive expectancies.
- No significant differences were found for depression symptoms at follow-up.
Insight
This study reveals that the Best Possible Self task works by directly improving both future expectancies and mood, but these improvements differ in how long they last.
Positive expectancies (optimism) showed a more lasting improvement over a week, whereas mood benefits were strong immediately but faded by follow-up.
Interestingly, changes in expectancies helped explain changes in mood right after the task, confirming that boosting optimism can improve emotional state.
Moreover, this study is one of the first large trials to show that BPS may have a small-to-moderate effect on reducing anxiety symptoms after a week, mediated by improved optimism about the future.
This suggests that optimism may protect against anxiety by changing how people expect future events, which fits with cognitive models of anxiety emphasizing expectancies and threat perception.
The lack of significant effects on depression symptoms aligns with previous mixed findings.
It could be that depression requires more intensive or sustained interventions than a single BPS session, or that those with higher depression symptoms are less likely to complete follow-up.
This research extends previous studies by including both positive and negative expectancies and mood measures, testing mediation in both directions, and focusing on symptom severity outcomes.
It also highlights the value of large, well-powered samples and preregistration for producing reliable evidence.
Future research could explore:
- Effects of multiple or longer BPS sessions
- BPS effects in clinical samples with diagnosed anxiety or depression
- Other mechanisms, such as self-efficacy or goal motivation
- How culture influences responses to BPS, given some unique findings in this Turkish sample
Clinical Implications
- The BPS task could be a low-cost, easily administered intervention to enhance optimism and mood in non-clinical and possibly clinical populations, such as university students experiencing anxiety.
- Because positive expectancies were key in reducing anxiety symptoms, interventions targeting optimism directly may complement cognitive-behavioral therapy (CBT) for anxiety.
- The task’s brevity (about 21 minutes online) makes it feasible for use in digital mental health platforms or as a homework activity in therapy.
- Clinicians could encourage clients to regularly imagine their best possible future selves to build hope and reduce anxiety.
- However, mood improvements were short-lived, so the BPS may be best combined with other treatments for sustained mood benefits.
- Practical challenges include ensuring engagement and vividness in imagining the future, especially when delivered remotely or without therapist support.
Strengths
- Large sample size (N=240), much larger than typical BPS studies, increasing confidence in results
- Preregistered design and public availability of data increase transparency and reproducibility
- Inclusion of both positive and negative expectancies and moods provides a comprehensive picture
- Mediation analyses clarify mechanisms of change, addressing gaps in prior research
- Inclusion of clinical symptom measures (anxiety and depression) bridges experimental and applied research
- Online delivery mirrors real-world application and shows feasibility in digital formats
Limitations
- Sample consisted of mostly healthy university students, limiting generalizability to clinical or older populations
- Single session intervention with only short-term follow-up; longer or repeated sessions may be needed for lasting effects
- The mood measure (PANAS) captures mainly high-arousal states and may miss important low-arousal emotions like calmness
- Self-report measures may be subject to bias, and online delivery prevented verification of task engagement
- Anxiety and depression diagnoses were self-reported, not clinically confirmed
- Cultural factors in Turkey may influence results and limit generalizability to other cultures
Socratic Questions
- How might the results differ if the sample included people diagnosed with clinical anxiety or depression?
- Could repeated administrations of the BPS task produce more lasting mood improvements? Why or why not?
- How might cultural differences affect how people respond to imagining their best possible self?
- What are the strengths and weaknesses of using self-report measures to assess expectancies and mood?
- Could the observed reductions in anxiety symptoms be explained by factors other than improved positive expectancies?
- How might the BPS task interact with other therapeutic interventions, like CBT?
- If the task primarily improves expectancies rather than mood, should future interventions focus more on cognitive reframing?
- How could future studies improve measurement of mood, especially low-arousal positive states?
- What ethical considerations arise when using positive psychology interventions in clinical populations?
- How would you design a follow-up study to test the long-term effects of the BPS task?
Booth, R. W., Erhan, K., Erkocaoğlan, O., Kuşpınar, H., & Yaldırak, K. (2025). The best possible self task has direct effects on expectancies and mood, and an indirect effect on anxiety symptom severity. Emotion, 25(4), 964–971. https://doi.org/10.1037/emo0001481
