de Maat, Saskia3; de Jonghe, Frans3; Schoevers, Robert3; Dekker, Jack1,2
1Mentrum Institute for Mental Health, Amsterdam, The Netherlands
2Department of Clinical Psychology, Free University Amsterdam
Correspondence: Jack Dekker, Mentrum Institute for Mental Health, PO Box 75848, 1070 AV, Amsterdam, The Netherlands
Original manuscript received 26 February 2008, accepted for publication subject to revision 16 May 2008; revised manuscript received 3 June 2008.