The Health Area Survey Nijmegen interviewed 3232 residents (aged 18-64) in a Dutch region, encompassing one major city (Nijmegen) and ten villages.

The prevalence of PSE cases estimated with logistic regression was nearly three times more common in the urban than in the rural communities. This fact could not be explained in terms of selective non-response, confounding variables or response sets. To unravel the relationship between degree of urbanisation and psychiatric caseness, a longitudinal survey is imperative.