Thirty studies reported prevalence of ซึมเศร้า (depression) in AD ranging from 19% to 78%. Overall, there were 9,012 AD patients with a pooled prevalence of 42% (95% CI 37–46%) และ a significant ความไม่เหมือนกัน (heterogeneity) (I2 = 95.2%, P < 0.05) between estimates (Supplementary Fig. 9). The meta-regression analyses of all 9 factors revealed that the factor of age (p = 0.002) might explain some of the variance in the estimates across studies (Table 1).