Correlation between methadone dosage, cortisol plasma level and depression in methadone-maintained patients

Background. Opioids can affect neuroendocrine functions, with the consequence that various endocrine abnormalities, including the increased level of cortisol that can result from depression, may be acceptable in patients who use opioids. Aim of this study is to examine the correlation between methadone dosage, cortisol plasma level and depression in methadone-maintained patients. Methods. This is an analytical, cross-sectional study that included 45 patients, who were divided into two groups. The first group consisted of 10 patients (4 females and 6 males), whose doses ranged between 10 and 55 mg. The second group consisted of 35 patients (5 females and 30 males), whose doses ranged between 65 and 120 mg. To discover demographic characteristics we used medical records, to determine cortisol plasma level we relied on the Chemiluminescence Immunoassay (CLIA) method, and to determine depression we made use of the Beck depression inventory (BDI). The results were statistically analysed using a combination of descriptive methods the t-test for independent samples, the chi(2) test, the Mann-Whitney U test and the Pearson coefficient of linear correlation. Results. The results obtained show statistically significant differences between the two groups in terms of their BDI scores, with higher scores indicating patients who were taking higher doses. There is a statistically significant correlation between cortisol plasma level and depression, but not between methadone maintenance dose and cortisol plasma level, even if a high proportion of patients in the group taking higher doses showed a higher cortisol plasma level. Conclusions. In methadone-maintained patients the methadone dose is not statistically correlated with cortisol plasma level, but some other factors in the group taking higher methadone doses tend to determine higher BDI scores.