CORRECTION ========== An editorial error occurred in this paper by [Professor Wiggins and others (2004;58:779–87)](http://jech.bmj.com/lookup/volpage/58/779). The keys to the symbols in figures 2, 3, and 4 were omitted. In figure 2 diamonds represent employed, squares unemployed, and triangles inactive. In figure 3 diamonds represent previous GHQ 0, crosses previous GHQ 3, and bars previous GHQ 6. In figure 4 diamonds represent previous GHQ 0, crosses previous GHQ 3, and bars previous GHQ 6.