Structural brain parameters and treatment outcome in major depression – neuroendocrine determinants

Introduction:

Increased aldosterone (aldo) levels and central mineralocorticoid-receptors (MR) activation are linked to therapy resistance to antidepressants. Apart from regulating of slow wave sleep, heart rate variability, and salt preference; aldosterone affects the secretion of cerebrospinal fluid.

Methods:

17 patients with major depression, were examined 3 times during 6 weeks. 13 patients completed the study. Central and peripheral MR related biomarkers (saliva aldo and cortisol; plasma vasopressin and oxytocin; slow wave sleep, heart rate variability, salt taste preference) and psychometrics were determined as well as magnetic resonance imaging measures (3 tesla) of the volume of specific anatomical areas, using Freesurfer 6 software for automatic volume detection.

Results:

Superior response and outcome, as characterized by the HDRS-21 and CGI-S, respectively, is correlated to lower volume of the lateral ventricles, total ventricular volume and the size of the choroid plexus (all p < 0.05), and by trend correlated to higher volume of the central (CCC) and mid anterior corpus callosum (MACC) (p < 0.1). The volume of the CC is inversely correlated to that of the ventricular system. The volume of the ventricular system is positively correlated to plasma vasopressin and body mass index (BMI), whereas the total volume of the CC is negatively correlated to the saliva concentration ratio of aldo/cortisol.

Conclusion:

Neuroendocrine (aldo/cortisol ratio; vasopressin) and metabolic (BMI) parameters determine the ventricular volume and the volume of the corpus callosum. This may link these markers to the pathophysiology of therapy refractoriness in depression.