Objectives Alcohol is metabolized to acetaldehyde by alcohol dehydrogenase enzyme in the liver and then acetaldehyde is metabolized to acetone by aldehyde dehydrogenase (ALDH) in the liver. There are two main ALDH enzymes which metabolize the acetaldehyde produced during ethanol oxidation. In particular, in the presence of the ALDH2 1^*2 allele, the activity of the ALDH 2 enzyme is lowered. As a result, acetaldehyde metabolism is slowed down and acetaldehyde accumulates in the body compared to the ALDH2 1^*1 allele. There are many studies that have investigated the blood acetaldehyde concentration according to the ALDH2 genotype, but there are few studies to compare this with age. So we investigated the blood acetaldehyde concentration according to ALDH2 genotype, age and gender. Methods According to the ALDH2 genotype, we divided the group by gender and age. We divided the age group in to three groups which ranged from 20 to 34 years old, from 35 to 49 years old, and lastly from 50 to 64 years old. And then we collected blood samples after 15 min, 30 min, 1 hr, 2 hr, 3 hr, 4 hr, 5 hr and 15 hr of after drinking to measure the blood acetaldehyde concentration. Results In ALDH2 1^*2 allele group, there are significant differences of the blood acetaldehyde concentration between the age groups. In ALDH2 1^*2 allele and male group, there are significant differences of the blood acetaldehyde concentration between the age groups. Conclusions There are significant differences of the blood acetaldehyde concentration between the age groups according to ALDH2 genotype. Also, there are significant differences of the blood acetaldehyde concentration between the age groups with male gender and ALDH2 1^*2 allele. Studies about other factors that may influence the blood acetaldehyde concentration are needed.

Objectives We conducted a meta-analysis of randomized controlled trials to investigate the therapeutic effects of mindfulness-based interventions on depressive symptoms in patients with major depressive disorder. Methods In February 2021, we searched Embase, MEDLINE, Cochrane Library, PsycINFO, CINAHL, and AMED. Under the guidance of the corresponding author, two evaluators independently reviewed and selected articles based on predetermined selection criteria. Results Based on the selection criteria, we systematically screened and included a total of 12 randomized controlled trials comprising 720 cases for the final analysis. Utilizing a random-effects model for data analysis, we determined the Hedges' g value to be 0.787, indicating a medium-sized effect according to Cohen's interpretation. The 95% confidence interval for the effect size ranged from 0.414 to 1.160 (p-value < 0.0001). Conclusions This study reveals the potential effectiveness of mindfulness-based interventions in treating depressive symptoms among patients with major depressive disorder.