Abstract
BACKGROUND: Adolescent depression is a public health problem. Possible risk factors of adolescent depression include family history, adverse childhood experience, and bully victimization. Cross-sectional study also showed that more urinary phthalate esters (PAEs) and heavy metals were related with more depressive symptoms after controlling confounding variables; there is also some studies showing the relationship with PAEs and anxiety. However, studies regarding PAEs and heavy metals and adolescents are scarce. Thus we arranged the study. AIMS & OBJECTIVES: We aim to investigate the relationship between levels of PAEs and heavy metals and depressive symptoms among adolescents. METHOD: We recruited adolescents from school and the internet. We collected baseline level of urinary PAEs and heavy metals. They filled in Patient Health Questionnaire-9 (PHQ-9) and Youth self-report form (YSR), living habits regarding PAEs and heavy metal exposure. We divided the participants into two groups: a high depressive group (PHQ-9 ≥ 13) and a low depressive group (PHQ-9 < 13). Logistic regression analysis was conducted to identify factors associated with depression. While analyzing the data, we controlled their sociodemographic data, sex, age, urinary creatinine, history of being bullied, family history of psychiatry, physical illness, social support, childhood abused experiences, to explore the influence of PAEs and heavy metals on adolescent depressive symptoms. RESULTS: We recruited 551 adolescents from school and the internet, with mean age 16.66 (Standard deviation, STD, 1.03) and 78.2% of them are girls. We invited more girls because the prevalence of depression is higher among girls. Mean score of PHQ-9 at baseline was 4.86 points (STD 4.85). There are 48 adolesents in the high depressive group and 503 in the low depressive group. The study found that the geometric mean of PAEs in Taiwan is generally lower than in other countries, while the levels of heavy metals fall in the middle range. A cross-sectional examination revealed several risk factors for depressive symptoms, including longer hours of incense burning at home (OR=1.005, 95% C.I.=1.001~1.008), food contact with plastic wrap (OR=3.878, 95% C.I.=1.216~12.373), higher frequency of seafood consumption (OR=1.051, 95% C.I.=1.005~1.098), increased cigarette use (OR=1.186, 95% C.I.=1.053~1.335), more experiences of childhood trauma (OR=1.107, 95%C.I.=1.058~1.158), a family history of psychiatric issues (OR=5.481, 95% C.I.=2.084~14.413), lower zinc levels (OR=0.996, 95% C.I.=0.993~0.999), and higher tin levels (OR=1.593, 95% C.I.=1.072~2.368). DISCUSSION & CONCLUSIONS: This study found that, in addition to known risk factors such as childhood trauma and family history, there are also relevant environmental factors associated with high scores on the adolescent depression scale. These environmental factors are areas that adolescents should be aware of, and those with more risk factors for depression should pay particular attention to and adjust their environmental influences.