Association of plain water intake with self-reported depression and suicidality among Korean adolescents.

Objectives: Adolescent depression and suicidality are serious health problems worldwide. Lower plain water intake has been proposed as a risk factor for depression in adults. This study investigated the association of daily plain water intake with self-reported depression and suicidality among Korean adolescents.

Methods: We used nationwide data from 112,250 students aged 12-18 years who participated in the Korean Youth Risk Behavior Web-based Surveys in 2019 and 2020. Daily plain water intake was categorized as <1 glass, 1-2 glasses, and ≥3 glasses. The adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for self-reported depression and suicidality were calculated using multiple regression analyses.

Results: The weighted prevalence rates of self-reported depression, suicidal ideation, suicide planning, and suicide attempts were 26.7%, 12.0%, 3.8%, and 2.5%, respectively. Of the participants, 3.9%, 18.5%, and 77.7% were categorized into the <1 glass/day, 1-2 glass/day, and ≥3 glass/day groups, respectively. Compared to the reference group (≥3 glass/day), the lowest level of water intake (<1 glass/day) was associated with higher odds of self-reported depression (aOR, 1.30; 95% CI, 1.20 to 1.39), suicidal ideation (aOR, 1.39; 95% CI, 1.27 to 1.55), suicide planning (aOR, 1.46; 95% CI, 1.25 to 1.69), and suicide attempts (aOR, 1.38; 95% CI, 1.15 to 1.67). Moderately lower water intake (1-2 glass/day) showed slightly increased odds of self-reported depression (aOR, 1.05; 95% CI, 1.01 to 1.10) and suicidal ideation (aOR, 1.08; 95% CI, 1.03 to 1.14).

Conclusions: Lower plain water intake was significantly associated with a higher risk of self-reported depression and suicidality among Korean adolescents. Since this cross-sectional study is unable to establish a causal relationship, it underscores the need for additional longitudinal research.