The impression that the prevalence of mental disorder has been increasing during the last decades is only partially justified. The considerable increase in the demand for psychiatric and psychotherapeutic help is influenced by quite a number of factors that vary in nature and direction. The most essential contribution was made by changes in the age composition of the population - and here primarily by the growing number of mentally ill elderly persons - and by the enormous increase in life expectancy. In milder psychiatric disorder the increase in the utilization of medical help is mainly due to new ways of treatment and to the great enlargement of psychiatric and psychotherapeutic services in most industrial countries, for which the zeitgeist of transition from a predominance of natural science to a more psychological understanding of life forms the background. Civilizational factors in a closer sense, like the raising of the achievement level for school beginners or alterations in the threshold of tolerance between mental illness needing medical intervention and mental suffering to be borne with submission to God's will, play an essential role particularly for the widening of the disease concept and thus for changes in the frequency of certain deficits of achievement and feeling, such as 'reading disorder' or depressive states. The fact that the age-corrected risk of falling ill with schizophrenia has remained stable over many decades - wherever it could be investigated - does not point to a relation with variable environmental factors like industrialization, civilization or social order. In contrast with this disease in a closer sense, the rates of psychiatrically relevant forms of deviant behaviour - suicidal attempts, drug- and alcohol-related disorders - show rapidly changing upward and downward variations. Thus, they are more comparable to criminality rates that vary over time and culture. There is obviously a relation between changes in the frequency of deviant behaviour and changing patterns of values in society, such as the reduction of educational intensity and the commitment of adolescents to norms and convictions of their parents. This is why the most distinct changes in these rates occur at the age most accessible to contemporary or fashionable influences: in youth and younger adult age. Except for age-related changes, we do not seem to have become more ill than the generation of our parents, but more pessimistic.