Saliva cortisol and male depressive syndrome in a community study. The Sudurnesjamenn study

The association between testosterone levels and depression is unclear. The relationship has been described as complex, i.e. more U (J)-shaped than linear in some previous studies.
The primary aim of this study was to examine the relationship between saliva testosterone level variations and different levels of male depressive symptoms in a community sample. The secondary aim was to investigate whether simultaneous testing of evening cortisol and testosterone improved the detection of depression.
In a community study, 534 males were screened, using the Beck Depression Inventory (BDI), the Gotland Male Depression Scale (GMDS) and the Montgomery-Åsberg Depression Rating Scale (MADRS). Those with signs of depression (n = 65) and randomly selected controls (n = 69) had psychiatric evaluation for depressive disorder. In a sub-sample (n = 51) saliva testosterone was measured twice on a single day.
Testosterone morning values were significantly higher than evening values (236 vs. 145 pg/ml, P = 0.009). Evening testosterone was significantly higher in depressive males, according to both MADRS (P = 0.028) and BDI (P = 0.036). Having depression increased the likelihood of being in the highest third of testosterone levels (BDI P = 0.021; MADRS P = 0.018). Positive correlation was between total BDI score and elevated evening testosterone with and without psychotropics (P = 0.017; P = 0.002). Correlation was between elevated evening cortisol and evening testosterone levels (P = 0.021) though simultaneous testing did not increase specificity of detecting depression.
Evening saliva testosterone measurements seem the most informative, as they correlate with male depressive syndrome. Simultaneous testing for evening cortisol and evening testosterone levels did not increase specificity for clinical diagnosis of depressive disorder.