Estimates of the numbers of people suffering from<unk> s and major depressive disorder (MDD) vary significantly. Overall, 13-20% of people will experience significant depressive symptoms at some point in their life. The overall prevalence of MDD is slightly lower ranging from 3.7-6.7% of people. In their lifetime, 20% to 25% of women, and 7% to 12% of men will suffer a<unk> . The peak period of development is between the ages of 25 and 44 years. Onset of<unk> s or MDD often occurs to people in their mid-20s, and less often to those over 65. The prevalence of depressive symptoms in the elderly is around 1-2%. Elderly persons in nursing homes may have increased rates, up to 15-25%. African-Americans have higher rates of depressive symptoms compared to other races. Prepubescent girls are affected at a slightly higher rate than prepubescent boys. In a National Institute of Mental Health study, researchers found that more than 40% of people with post-traumatic stress disorder suffered from depression four months after the traumatic event they experienced. Women who have recently given birth may be at increased risk for having a<unk> . This is referred to as postpartum depression and is a different health condition than the baby blues, a low mood that resolves within 10 days after delivery.
Major depressive episode
Major depressive disorder
Outline of bipolar disorder
Depression 
Late life depression
Atypical depression
Postpartum psychosis
Postpartum depression