Objective: To assess the validity and reliability of the Montgomery and Asberg Depression Rating Scale (MADRS Thai) by comparing DSM-IV TR criteria and Hamilton Rating Scale for Depression (HRSD).

Material and Method: Descriptive study. Subjects were recruited from the psychiatric out-patient clinic Siriraj Hospital. Subjects were assessed by MADRS Thai version and clinical interview. Validity: Opinion from psychiatric and social science experts, evaluating 13 study cases and 27 control cases, compared to the Global Assessment Scale (GAS) and to the changed scale of HRSD.

Reliability: Inter-rater and Intra-rater reliability and Internal consistency.

Results: Content validity is above 0.5 except the item of Inner tension, Lassitude and Inablilty to feel. Criterion validity when compared to DSM-IV TR or HRSD, the sensitivity, specificity, PPV and NPV were all 100%. Pearson correlation coefficients sensitive to change were -0.49 (p-value = 0.11) and 0.679 (p-value = 0.025) when compared to 1) DSM-IV TR and 2) HRSD, respectively. ICC of Inter-rater and Intra-rater reliability were both 0.99 when compared to either 1) DSM-IV TR or 2) HRSD. Cronbach’s alpha of Internal consistency was 0.96 and 0.92 when compared to 1) DSM-IV TR and 2) HRSD, respectively.

Conclusion: The result suggested that the Thai version of the Montgomery and Asberg Depression Rating Scale had a very good validity and reliability. Therefore, it can be used as a diagnostic test in Thai depressed patients.

Keywords: Montgomery and Asberg Depression Rating Scale -Thai, DSM-IV TR, Social function