Reliability and validity of the Dutch Anxiety, Depression And Mood Scale in adults aged

Background Reliable and valid screening instruments for depression and anxiety are needed for adults with intellectual disabilities. Methods Internal consistency (n = 198), inter-rater reliability (n = 41), test-retest reliability (n = 37) and criterion validity (n = 43) were studied in adults aged between 18 and 49 years. Internal consistency was also studied in a sample with epilepsy (n = 98). Results Internal consistencies of the Dutch ADAMS total scale and subscales were satisfactory to good (alpha = 0.76-0.92), as well as in the subgroup with epilepsy (alpha = 0.74-0.88). Inter-rater reliability and test-retest reliability were fair to excellent for the total scale (ICC's: 0.57-0.84) and subscales (ICC's: 0.43-0.86). The criterion validity of the Dutch ADAMS Depressive Mood subscale was good with a sensitivity of 88% (95% CI: 53%-98%) and a specificity of 80% (95% CI: 64%-90%). Conclusions Our study shows that the Dutch ADAMS is a reliable and valid instrument for adults aged between 18 and 49 years with intellectual disabilities (and comorbid epilepsy).