Figure 1

Minor allele frequency versus QIDS score. For the Sleep Clinic sample, the rs25702 minor allele frequency (MAF) with its 95% confidence interval range is plotted versus QIDS score ranges. QIDS scores correspond to the following levels of depression: mild (6–10), moderate (11–15), severe (16–20), and very severe (≥21) depression, where patients with scores <6 are not likely depressed and those >20 would usually not be observed in the clinic because they would need hospitalization. The lower the QIDS and the less depression observed, the more likely a patient was to have a minor allele.