Feasibility, Acceptability, and Preliminary Efficacy of a Positive Affect Skills Intervention for Adults With Fibromyalgia.

Background and Objectives: To examine the feasibility, acceptability, and preliminary efficacy of a positive affect skills intervention for middle-aged and older adults with fibromyalgia syndrome (FMS). Research Design and Methods: Ninety-five participants with FMS aged 50 and older (94% female) were randomized to 1 of 2 conditions: (a) Lessons in Affect Regulation to Keep Stress and Pain UndeR control (LARKSPUR; n = 49) or (b) emotion reporting/control (n = 46). LARKSPUR included 5 weeks of skill training that targeted 8 skills to help foster positive affect, including (a) noticing positive events, (b) savoring positive events, (c) identifying personal strengths, (d) behavioral activation to set and work toward attainable goals, (e) mindfulness, (f) positive reappraisal, (g) gratitude, and (h) acts of kindness. Outcome data were collected via online surveys at baseline, postintervention, and 1-month follow-up. Results: Completion rates (88%) and satisfaction ratings (10-point scale) were high (LARKSPUR: M = 9.14, standard deviation (SD) = 1.49; control: M = 8.59, SD = 1.97). Improvements were greater in LARKSPUR participants compared with control participants on measures of positive affect (Cohen's d = 0.19 [0.15, 0.24]), negative affect (Cohen's d = -0.07 [-0.11, -0.02]), and pain catastrophizing (Cohen's d = -0.14 [-0.23, -0.05]). Improvements in positive affect (Cohen's d = 0.17 [0.13, 0.22]) and negative affect (Cohen's d = -0.11 [-0.15, -0.06]) were maintained at 1-month follow-up. Dose-response analyses indicated that intervention engagement significantly predicted pre-to-post and post-to-follow-up reductions in pain catastrophizing. Discussion and Implications: The current preliminary findings add to existing literature and highlight the specific potential of internet-delivered positive affect skills programs for adults with FMS. Clinical Trial Registration: NCT04869345.