Dietary Plant Hormone and Mental Health

Subjective life-quality will be measured with the short version of the World Health Organization Quality of Life questionnaire (WHOQOL-BREF,). The WHOQOL-BREF is a self-administered questionnaire comprising 26 questions on the individual's perceptions of their health and well-being over the previous two weeks. Responses to questions are on a 1-5 Likert scale where 1 represents "disagree" or "not at all" and 5 represents "completely agree" or "extremely". For the present study only the three subscales (physical and psychological health, and social relationships) will be assessed.

Brief Symptom Checklist (BSCL former BSI), including various subscales such as depression, anxiety

Sleep quality is assessed with the Pittsburgh Sleep Quality Index (PSQI). Each of the sleep components yields a score ranging from 0 to 3, with 3 indicating the greatest dysfunction. The sleep component scores are summed to yield a total score ranging from 0 to 21 with the higher total score (referred to as global score) indicating worse sleep quality.

Stress will be assessed with the Stress and Coping Inventory (SCI).The SCI is used to determine the current stress load and stress symptoms and to illustrate how to deal with stress using five coping strategies. It comprises 10 scales with 54 items: (A) Current stress load (1) Stress due to uncertainty, (2) Stress due to overload, (3) Stress due to loss and actual negative events, (4) Total stress: Total stress due to insecurity, threat, overload or loss in important areas of life, (5) Physical and psychological stress symptoms; (B) Stress coping (Coping) (1) Positive thinking, (2) Active stress coping, (3) Social support, (4) Keeping faith, (5) Increased alcohol and cigarette consumption.