GAD2 and major depressive disorder: Could autoantibodies against GAD65, which are associated with diabetes type 1, brain disorders, anxiety, and depression, also have a significant role in the development of Frozen Shoulder (FS), especially considering its higher occurrence in patients with hypothyroidism and Hashimoto’s disease (Brindisino et al., 2022), and the elevated risk of endocrinological autoimmune diseases related to these autoantibodies (Gambelunghe et al., 2000)?