Positive autobiographical memories (AMs) have the potential to repair low mood, but previously depressed individuals have difficulty leveraging their positive AMs for emotion regulation purposes. We examined whether previously depressed individuals benefit from guided, deliberate recollection of preselected AMs to counteract low mood in daily life, utilizing individuals’ smartphones to facilitate recollection. Sixty participants enrolled in 2020 were randomly allocated to retrieval of positive or everyday activity AMs and completed ecological momentary assessment of emotional experience for 3 weeks. Participants first created a pool of six memories for the digital AM diary. This was followed by a training week with two recollection tasks daily and a 2-week follow-up period where the diary could be used spontaneously. The positive condition experienced a greater increase in feelings of happiness and a greater decrease in feelings of sadness from pre- to post-AM recollection. While participants in the positive condition used the AM technique more frequently overall during the 2-week follow-up, the effect of condition was moderated by changes in feelings of sadness. The more participants experienced an emotional benefit during the training week, the more they used it spontaneously. Emotional vividness of untrained positive AMs at the 2-week follow-up differed depending on whether they were assessed before or after the first pandemic lockdown. Residual depressive symptoms decreased in both conditions over the study course, while mental well-being remained unchanged. Strengthening positive, self-affirming AMs in daily life may provide a tool to support regulation of transient low mood in those remitted from depression. (PsycInfo Database Record (c) 2024 APA, all rights reserved) (Source: journal abstract)