At the end of study, subjects on P8 showed reduced scores of stress (mean difference 2.94; 95% CI 0.08 to 5.73; P = 0.048), anxiety (mean difference 2.82; 95% CI 0.35 to 5.30; P = 0.031) and total score (mean difference 8.04; 95% CI 0.73 to 15.30; P = 0.041) as compared to placebo after 4-weeks, as assessed by the DASS-42 questionnaire.
The consumption of DR7 (1×10<sup>9</sup> cfu/day) for 12 weeks reduced symptoms of stress (<i>P</i>=0.024), anxiety (<i>P</i>=0.001), and total psychological scores (<i>P</i>=0.022) as early as 8 weeks among stressed adults compared to the placebo group as assessed by the DASS-42 questionnaire.
These results support the psychometric properties of the DASS-21 Depression and Anxiety scales when measuring psychological distress in cancer patients.
The DASS-21 is reliable and suitable for use to assess symptoms of common mental health problems, especially depression and anxiety among Vietnamese adolescents.
The DT correlated with the DASS-21 depression (r = 0.45, p < 0.001), anxiety (r = 0.56, p < 0.001) and stress (r = 0.64, p < 0.001) subscales demonstrating validity.