Eligible participants in the main cohort study will be approached by call or during face-to-face sessions. Parents who express interest in participation will be provided with an information sheet about the research and asked to sign the consent form for themselves and for their children. After providing consent, the parent of each parent-child pair will complete a set of structured questionnaires on parental mental health and HRQOL, parenting style, neighborhood cohesion, and their children's well-being and behaviors. Physical examination including blood pressure, heart rate, weight, height, and waist-to-hip ratio will also be carried out on both parents and children. A swab of buccal cells will be taken from each child. Venous blood will be sampled from each parent.