In schizophrenia and MDD, Spearman correlation coefficients showed that oxy-Hb, deoxy-Hb, total-Hb, oxy-Hb/blood-Hb, deoxy-Hb/blood-Hb, total-Hb/blood-Hb, and SO2 were not correlated with the chlorpromazine-equivalent dose of anti-psychotic medication and the fluvoxamine-equivalent dose of anti-depressant medication (p > 0.05). This evidence concerns the gene GSTM1 and major depressive disorder.