Analysis of underproductive days per week showed that patients with PPS in all the groups experienced a significantly higher number of underproductive days compared to patients without PPS (F-value = 6.1 for the combination of diagnoses and pain p < 0.0001, p = 0.0016, p = 0.0005; PPS+ vs. PPS- for GAD+MDD+, GAD+MDD-, and control groups, respectively) (Figure 3). The gene discussed is GAD1; the disease is generalized anxiety disorder.