Analysis Assays of Melatonin and cortisol: Melatonin in saliva was measured by a direct radioimmunoassay (RIA). The kit is manufactured by LDN GmbH & Co, KG, Nordhorn Germany (Cat-No: DSL-BA-1200) and is specially made for the quantitative determination of melatonin in saliva. The cross-reactivity of the assay for N-acetylserotonin, 5-methoxytryptophol, and 5-methoxytryptamine is 0.80%, 0.70%, and 0.08%. Serotonin, 5-methoxyindole-3-acetic acid is < 0.01%, respectively. The sensitivity of the assay is 1 ng/L. The intra- and inter-variations are 11.3% and 12%, respectively. Salivary cortisol concentrations were measured with a competitive solid-stage radioimmunoassay [Coat-A-Count, Diagnostic Products Corp (DPC)]. The protocol followed the instructions of Coat-Count Free Cortisol in Saliva kit from DPC.