Association of Baseline Depressive Tendency with Post-Counseling Clinical Status in Patients with Thymoma-Associated Myasthenia Gravis

Background: Depressive symptoms are highly prevalent among patients with thymoma-associated myasthenia gravis (MG) and are associated with poorer clinical status and quality of life. However, their relationship with psychological counseling outcomes remains insufficiently investigated. Objectives: This study aimed to examine the association between baseline depressive tendency, baseline clinical status, and post-counseling clinical outcomes in patients with thymoma-associated MG. Methods: This single-group pre-post exploratory pilot study enrolled 17 patients with thymoma-associated MG who received eight sessions of Gestalt-oriented psychological counseling. A depressive tendency was defined as a baseline Patient Health Questionnaire-9 (PHQ-9) score ≥10 (n = 6, 35.3%). Clinical outcomes, including the Myasthenia Gravis Activities of Daily Living scale (MG-ADL), Myasthenia Gravis Quality of Life 15-item scale (MG-QoL15), mental BMI (mBMI), and PHQ-9 scores, were assessed before and after the intervention. Multivariable linear regression analyses were performed using baseline depressive tendency as the primary predictor of each post-counseling outcome. The models were sequentially adjusted for the corresponding baseline outcome score and subsequently for age and sex. Results: Following the counseling intervention, statistically significant pre–post changes were observed in MG-ADL (p = 0.044), mBMI (p = 0.018), and PHQ-9 (p = 0.002) scores. After adjustment for the corresponding baseline outcome score, age, and sex, baseline depressive tendency was associated with less favorable post-counseling mBMI (β = −3.52, robust 95% CI −6.19 to −0.86, p = 0.014) and MG-ADL scores (β = 1.70, robust 95% CI 0.51 to 2.89, p = 0.009). Conclusions: Baseline depressive tendency was associated with poorer baseline functional and disease-specific quality-of-life status and with less favorable adjusted post-counseling MG-ADL and mBMI scores. These associations met the Benjamini–Hochberg threshold but not the more conservative Benjamini–Yekutieli threshold. Given the small sample and uncontrolled pilot design, the findings should not be regarded as evidence of counseling effectiveness and require confirmation in prospective controlled studies.