BDNF and generalized anxiety disorder: Even controlling for age, gender, and education levels (set as a dummy variable), the current duration, comorbid AP, and/or GAD, our results revealed that baseline STAI state scores (b = −0.07, p = 0.004), serum BDNF levels (b = 0.35, p = 0.007), and PDSS-CV scores (b = −0.25, p = 0.007) contributed to the prediction of PHQ-15 changes, i.e., changes in somatic symptoms post-escitalopram treatment, and the explanation of these three variables for the regression model was 31.3% (F = 5.05, p < 0.001), see Table 2.