Preliminary Psychometric Evaluation of the Hamilton Depression Rating Scale in Methamphetamine Dependence

Abstract

OBJECTIVE: The purpose of this study was to test the initial psychometric properties of the 17-item Hamilton Depression Rating Scale (HAM-D) in individuals with and without major depressive disorder who use methamphetamine. We used data from two completed studies and two ongoing clinical trials. The HAM-D has well established reliability and validity in a variety of populations. However, there are no published reports of reliability and validity of the HAM-D in a methamphetamine using population. METHODS: HAM-D and depression status data were extracted from four separate studies for this psychometric assessment. Using these data, we evaluated three measures of construct validity: internal consistency, contrasted groups validity and factorial validity. RESULTS: We found potential concerns with the construct validity of the HAM-D in users of methamphetamine. Intercorrelations between items were primarily less than 0.20 and the Cronbach's alpha value in this sample was 0.58 indicating potential issues with internal consistency. The results of a two sample t-tests suggest concerns with contrasted group validity, as no significant difference in average scores were found for nine items. Consistent with previous studies, a principal component analysis indicates that the HAM-D is multidimensional. CONCLUSIONS: The 17-item HAM-D might not reliably and validly measure depression severity in a methamphetamine using population. Given our small sample, additional research is needed, though, to further test the psychometric properties of the HAM-D in individuals who use methamphetamine.