Depression, Anxiety, Stress Scale 21 (DASS-21)
This is a self-report psychometric instrument designed to measure the negative affective dimension of depression, anxiety, and stress (27). It consists of 21 items which are categorized into three dimensions (depression, anxiety, stress) and each dimension includes 7 items. Scoring is done on a four-point Likert-type scale (where 0= Did not apply to me at all, 3= Applies to me very much, or most of the time). Each participant’s scores are summed to calculate a total negative emotional state score. The upper value is 63 for the entire questionnaire. For each scale, all scores are summed and then multiplied by 2 since the standard DASS consists of 42 items. The DASS-21 has been translated into 45 different languages (28) with high reliability and validity. The Greek translation by Dr. George Lyrakos is considered a highly reliable and valid measure (29). This tool is protected and so licence to use was obtained by the researcher.