Nowadays, there is an incidence of depressive disorder is increasing worldwide. In the USA, the lifetime prevalence rate of major depressive disorder was about 16 %.
High prevalence of the depressive disorder has been described in Finland (approximately 9 %). Similar findings have been noted in Czech republic, as well (about 9,4 %).
According to the World Health Organization statement, depressive disorder will be the first-leading contributor to Global Burden of Disease of the western world in 2030. Increasing prevalence rate of the depressive disorder in the developed countries has probably more than one cause.
The populations, living in developed countries are characterized by an increasing occurence of the overeating, improper food composition, sedentary lifestyle and by lack of sleep. The increasing rate of the social isolation, loneliness and other community factors of the modern world may also play a role.