Data analysis
depressive disorder
Data are publicly available through Open Science Framework (First, a one-way ANOVA was conducted to estimate differences in RMSSD during the self-compassion imagery, relaxation imagery and control task at session 1. Paired sample Group-level analyses can often mask important clinical information: for example, they do not distinguish a situation where some participants show strong threat-responses and others show strong positive responses from a situation where all participants show little change. Reliable or clinically-significant change analyses can offer useful insights at an individual level. A reliable change index (RCI; [Reliable change is not suitable for analyzing HRV data since internal consistency cannot be calculated. Instead, we calculated how many individuals showed a clinically-significant HRV response for each session, which we defined as 5ms change in RMSSD during the experimental task (CFI or relaxation) compared to the control task. This value was drawn from literature on the differences in baseline levels of HRV between healthy controls and patients with depressive disorder [We tested the following hypotheses (H1) At session 1, group mean HRV will be lower during the control task than for both CFI and relaxation imagery; (H2) Examining individual HRV data, fewer individuals will show a clinically-significant negative response to compassion than to relaxation at each testing session (defined as 5ms lower than their HRV during a control task) and equally, more individuals will show a positive response to compassion than to relaxation; (3) Over time, the number of individuals showing a clinically-significant negative HRV response to CFI and relaxation will decrease, and finally (4) Regarding self-reported affect (which was only measured during CFI), group means will demonstrate a pre-post improvement during CFI sessions in positive affect. Due to previous conflicting findings we did not make a hypothesis regarding whether negative affect would significantly change.