Does the prevalence of psychiatric disorders increase with urbanisation?
background There is a positive correlation between mental health service utilisation and levels of urbanisation. The 'Netherlands Mental Health Survey and Incidence Study' (NEMISIS) shows that psychiatric morbidity is higher in urban municipalities than in rural municipalities. The distinction between urban/rural was made in order to facilitate international comparisons.
aim A precise classification with 5 urbanisation categories was used to study the link between levels of urbanisation and 12-month prevalence of psychiatric disorders, taking confounders into account. method The Composite International Diagnostic Interview (cidi) was used to determine the prevalence of DSM-III-R disorders in a sample of 7076 people aged between 18 and 64 which was representative of the population as a whole. The study population was assigned to 5 urbanization categories (as drawn up by Statistics Netherlands) on the basis of municipality.
results The 12-month prevalence of psychiatric disorders increases with urbanisation. This pattern is particularly pronounced in the case of mood disorders and substance-related disorders. After correction for a range of confounders, the variations remain and a difference was also found for anxiety disorders.
conclusion The 12-month prevalence of psychiatric disorders increases with urbanisation and this correlation remains after correction for possible confounders.