Abstract

The present study aimed to verify the effects of a behavioral activation (BA) program on pain intensity, pain interference, pain catastrophizing, depression, activity frequency, and life satisfaction in patients with complex regional pain syndrome (CRPS). For this purpose, we applied a multiple baseline design consisting of baseline, treatment, and follow-up phases with four CRPS patients. The BA program consisted of a total of eight sessions, primarily conducted in a non-face-to-face, approximately once a week, with each session lasting about 30 to 60 minutes. The target activity was set to focus on positive mood related activities among those showing inconsistency before and after pain onset. Time-series data were collected through daily activity monitoring sheets, encompassing activity logs categorized by the time of day (morning, afternoon, evening), pain intensity, depression, frequency of target activity achievement, and reasons for not accomplishing target activity. The time-series data indicated a significant increase in the frequency of participants' target activity during the treatment phase. This pattern was sustained and even augmented during the follow-up phase. Additionally, depression exhibited a gradual decrease from the intervention phase to the follow-up phase. However, the decrease in pain intensity was relatively lower than the reduction observed in depression. Effect size (Cohen's d) was calculated by measuring participants' pain intensity, pain interference, pain catastrophizing, depression, and life satisfaction pre-, post-, and follow-up (one month after termination) to analyze the effects of the BA program. The results showed moderate to large effect sizes for all variables except pain intensity, and these effects were maintained and increased at follow-up. The findings suggest that the BA program, a psychological approach, is applicable to CRPS patients who experience extreme pain.