Objectives. Central monoaminergic dysfunction with autonomic nervous system dysregulation are reportedin major depressive disorder (MDD). Salivary α-amylase (sAA) activity and salivary 3-methoxy-4-hydroxyphenylglycol (sMHPG) are adopted as markers of central noradrenergic activity with salivary 5-hydroxyindole acetic acid (s5-HIAA) being indicative of central serotonin turnover. No data is available on baseline sAA, s5-HIAA and sMHPG in MDD being interrelated to the specific psychopathological dimensions and item performance of the Hamilton Rating Scale for Depression(HAMD-17) in MDD.
Material and methods. The basal sMHPG and s5-HIAA concentrations and sAA activity as correlated with HAMD-17 psychometric assessment were studied in this exploratory study of 20 adult, treatment-naïve MDD patients.
Results. The negative correlations between sMHPG and HAMD-17 items 7 (work and activities) (r = –0.56, p = 0.01) and 4 (early insomnia) (r = –0.45, p = 0.049) were foundpost hoc. On exploration the correlations between sAA and items 7 (work and activities) (r = –0.47, p = 0.04) and 12 (gastrointestinal symptoms) (r = 0.49, p = 0.03) were also observed with no such observation with regard to s5-HIAA.
Conclusions. On exploratory analysis, in basal, non-stimulated conditions baseline sAA, sMHPG levelsin MDD were found to be correlated with HAMD-17 items representing clinical symptoms attributable to primary noradrenergic dysfunction at the early stage of major depression. Saliva is a promising source of monoaminergic biomarkers in MDD research. However, further systematic studies are needed to contribute consistent results to aid standardization, in particular with psychometric measures.