The presence of putative medical confounders showed no effect on IGF-1 level, which does not correspond to studies showing decreased IGF-1 serum levels in diabetes [28], thyroid dysfunction [32], β-adrenergic medication [9], depression and/or anti-depressant medication [30,31], inflammatory diseases [29,39] and cancer [40]. This evidence concerns the gene IGF1 and depressive symptom measurement.