Age at onset of disease was 33.28 ± 12.24 years in the major depression group and 27.52 ± 4.70 in the bipolar group (t=2.53, p= 0.013). Duration of disease was 2.73 ± 4.70 years in the major depression group and 10.06 ± 10.16 in the bipolar depression group (t=-4.97, p=0.000) (Table 2).