## 2 Materials and Methods
### Experimental Procedure  
Prior to any test or intervention and before being evaluated for the study's inclusion criteria, all participants signed a written informed consent approved by the University of Chile Clinical Hospital Scientific Ethical Committee (Acta 019/2016). Data were collected at the beginning of the study and then again at the end of the study (see Figure 1).  
Participants provided behavioral and mood information through 3 clinical questionnaires: the HAM-D Scale [49] with 17 and 21 items, administered by a psychiatist, and the self-reported Beck Depression Inventory-II (BDI-II) [50]. Additionally, neurocognitive parameters, including working memory, attention, information processing, reaction time, social and emotion recognition, and decision-making, were evaluated for all subjects using the commercial Cambridge Neuropsychological Test Automated Battery (CANTAB).  
Blood samples were also collected from all subjects for a metabolic panel, a complete blood count (CBC), erythrocyte sedimentation rate (ESR), lipid profiles, thyroid function test, and activation of hemostasis and inflammation plasma markers. This included assessing platelet activation by measuring plasma levels of soluble CD40 ligand (sCD40L), Regulated upon Activation, Normal T Cell Expressed and Presumably Secreted (RANTES), Neutrophil-Activating Peptide-2 (NAP-2), and P-Selectin using commercial reagents and standards and the Enzyme-Linked Immunosorbent Assay (ELISA) kit. Levels of circulating endothelial cells (CECs) and soluble plasma markers were measured for evaluating endothelial dysfunction. CECs were isolated from peripheral blood using immunomagnetic beads coated with anti-CD146, stained for CD45 and Ulex Europaeus lectin, and counted  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Characteristic (Units)** & **Average (Range)** \\ \hline Age (years) & 34 (23–49) \\ Education (years) & 16 (12–21) \\ Body Mass Index (kg/m\({}^{2}\)) & 27 (18–49) \\ HamD 17 & 24 (14–40) \\ Beck score & 30 (12–46) \\ Thyroid-Stimulating Hormone (\(\mu\)U/mL) & 2.5 (1.0–7.5) \\ Total Cholesterol (mg/dL) & 175 (128–229) \\ Triglycerides (mg/dL) & 102 (43–249) \\ High-Density Lipoproteins (mg/dL) & 56 (23–85) \\ Low-Density Lipoproteins (mg/dL) & 100 (56–144) \\ Glycemia (mg/dL) & 89 (72–206) \\ C Reactive Protein (ug/mL) & 2.5 (0–19.8) \\ Erythrocyte Sedimentation Rate (mm/h) & 9 (2–28) \\ \hline \hline \end{tabular}
\end{table}
Table 1: Characteristics of the participants.  
under fluorescence microscopy. Plasma levels for soluble Intercellular Cell Adhesion Molecule (sICAM), Vascular Cell Adhesion Molecule (VCAM), Monocyte Chemoattractant Protein 1 (MCP-1), Vascular Endothelial Growth Factor (VEGF), and free Brain-Derived Neurotrophic Factor (BDNF) were also measured by using commercial reagents and the ELISA kit. Interleukin-6 (IL-6), Tumor Necrosis Factor alfa (TNF\(\alpha\)), and high sensitivity C Reactive Protein (hsCRP) were also measured by ELISA. Rho-kinase activity was assessed by the levels of phosphorylated-to-total myosin light chain phosphatase 1 (MYPT1-P/T) in circulating leukocytes. Plasma Malondialdehydehyde (MDA) levels for oxidative stress were also quantified [51].  
Finally, resting-state perfusion values for all brain regions using Single Photon Emission Tomography (SPECT) with \({}^{99\text{m}}\)Tc-ethylcysteine dimer (\({}^{99\text{m}}\)Tc-ECD) were also obtained. 'Abnormal' perfusion values were calculated for all brain regions using the Neurostat iSSP3.5 program provided online by Dr. [PERSON] ([[https://neurostat.neuro](https://neurostat.neuro)]([https://neurostat.neuro](https://neurostat.neuro)). utah.edu/, accessed on 7 May 2019). These particular values represented the difference between the individual perfusion for participants and the control average provided by the software obtained from a group of healthy adults matched for age with values outside \(\pm 2\) standard deviation flagged as 'abnormal'.