Writing to your past-self can make you feel better

Rosy retrospection, the tendency to view past events more favorably than present ones, is a common phenomenon. This "rosy view" often involves a fading affect bias, where unpleasant feelings about past events fade faster than pleasant ones. This bias might serve as a coping mechanism promoting well-being. The current research explores how rosy retrospection can be harnessed to improve mood. Positive autobiographical memories, particularly those with a social component, have been shown to buffer the effects of negative experiences, reducing stress responses and improving mood. Studies suggest that compassionate listening enhances the positive impact of positive memories and reduces the negativity of negative memories. Self-compassionate interventions, like letter writing, offer a private way to access and reframe these memories, particularly beneficial for those hesitant to disclose personal information. While writing to one's future self has shown benefits, the mechanisms might differ from writing to one's past self; the latter might provide comfort, while the former might induce anxiety. Time attitude (attitude towards past, present, and future) may also moderate the effect of letter writing. This study investigates the effects of writing compassionate letters to the past vs. future self, and the influence of the writing focus (social vs. self-experience) on mood in healthy undergraduates, considering their time attitudes.

Existing research demonstrates the positive effects of self-compassionate writing interventions on various aspects of mental well-being. Studies have shown its effectiveness in treating anorexia nervosa, improving body satisfaction, reducing shame, and mitigating smoking behavior. The "rosy retrospection" phenomenon and the fading affect bias provide a theoretical foundation for understanding the potential benefits of focusing on past positive experiences. Recalling positive memories, particularly social ones, has been linked to reduced stress responses and improved mood. Conversely, the act of writing to one's future self has been linked to improved self-control and future-oriented behaviors, but also potentially to increased anxiety if the individual is uncertain about future prospects. The role of social connection in positive memory recall is also highlighted, with research suggesting that socially rich memories are more frequently reminisced about and better buffer stress responses. Previous studies also highlight the importance of individual differences in self-disclosure and cultural factors in shaping the effectiveness of self-compassion interventions.

This study employed a two-experiment design. Experiment 1 used a within-subjects crossover design with 150 Japanese undergraduates (54 males, 94 females). Participants were randomly assigned to write a compassionate letter to their past self followed by their future self, or vice versa, with POMS2 (Profile of Mood States) administered before and after each writing task. Seven days later, participants repeated the letter writing and POMS2 assessment for the other time period. The Adolescent Time Inventory—Time Attitudes (ATI-TA) questionnaire was also administered. Experiment 2 used a between-subjects design with 62 Japanese undergraduates (22 males, 40 females) who hadn't participated in Experiment 1. Participants were randomly assigned to write a compassionate letter to their past self, focusing on either a solitary experience or a social experience. POMS2 was administered before and after letter writing. Sample size was calculated using G*Power. Data analysis in Experiment 1 included two-factor ANOVAs for TMD (Total Mood Disturbance) change, chi-square tests for mood change categorization, and ANOVAs on ATI-TA scores. Qualitative text analysis using KH Coder assessed the frequency of words describing others in letters. Experiment 2 used ANOVA for TMD change, chi-square tests for mood change, and ANOVAs on POMS2 subscales. All participants were healthy Japanese undergraduates, excluding those with mental disorders or psychedelic medication history. Written informed consent was obtained.

Experiment 1 revealed that writing to one's past self significantly reduced negative mood compared to writing to one's future self. Participants who experienced a positive mood change after writing to their past self exhibited a higher proportion of words describing others in their letters compared to those with negative mood changes. Individuals with less negative attitudes toward their past, present, and future were less affected by writing to their past selves. The reduction in negative mood was primarily driven by decreases in tension-anxiety and depression-dejection scores and an increase in vigor-activity scores on the POMS2. Experiment 2 demonstrated that focusing on a social experience in the past-self letter led to a significantly greater reduction in negative mood compared to focusing on a solitary experience. Specifically, the depression-dejection score decreased significantly more in the social connection group than in the self-alone group. Notably, the overall TMD change in Experiment 1 was approximately the average of the TMD changes observed in the two conditions of Experiment 2, suggesting a possible interaction between the time perspective (past vs. future) and the focus of the writing (social vs. solitary).

The findings support the hypothesis that writing compassionate letters to one's past self, especially focusing on social connections, can effectively elevate mood, particularly among individuals with negative time attitudes. This suggests that accessing and re-experiencing positive social memories can act as a coping mechanism for negative affect. The contrasting effect of writing to one's future self might be attributed to the anxiety associated with contemplating uncertainties about the future, although this requires further investigation. The significant role of social connection in buffering negative mood aligns with existing literature highlighting the importance of social support and belonging in mental well-being. The results indicate that the effectiveness of compassionate letter writing is moderated by both the target time period (past vs. future) and the content focus (social vs. solitary). The methodology of compassionate letter writing appears to offer a promising, easily accessible, and potentially highly effective tool for self-compassion interventions.

This study demonstrates the effectiveness of compassionate letter writing to one's past self in improving mood, particularly when focusing on positive social experiences. This technique appears most beneficial for individuals experiencing negative affect and those with negative time attitudes. Conversely, writing to one's future self may be more effective for promoting future-oriented behaviors and self-improvement. Future research should explore the use of this technique as a regular treatment for mood disorders and investigate the long-term impact and generalizability of the findings across diverse age groups and clinical populations. Further research should also examine the underlying mechanisms and the moderating influence of individual factors more comprehensively.

The study's limitations include its reliance on a sample of healthy Japanese undergraduates, limiting the generalizability of the findings. The relatively small sample size in Experiment 2 also needs consideration. While the study controlled for certain variables, other factors, such as individual life circumstances, mental health conditions beyond the exclusion criteria, or external events, could have influenced the observed mood changes and weren't explicitly accounted for. Future studies should address these limitations by including more diverse populations and implementing rigorous control measures to enhance the validity of the results.