Depressive disorders mostly develop between the ages of 25 and 45 years. Of all people with a lifetime history of depression, 40% first developed the disorder between the ages of 15 to 35. Depression is more prevalent in women than it is in men, with rates in adults being one and a half times and in older adults two times higher, while in children and adolescents (aged 13-17 years) this is even three times higher. Of the Dutch adult population (aged 18-65 years) in 2010, 7.4% women and 4.8% men were diagnosed with a mood disorder (a major depressive disorder, persistent depression/dysthymia, or bipolar disorder), representing a total of 384,600 women and 258,200 men. Disease course and the risk of relapse are similar for the sexes. Today, there are effective treatments, but not all types of depression respond equally well to treatment. In an estimated 10-20% of all treated patients the depression takes a chronic course, with symptoms persisting for two years or longer. This latter depressive type was formerly known as dysthymia but is now classified as persistent depressive disorder in the DSM-5.