Nevertheless, some studies, including the 2004 Belgian Health Survey discussed above, throw
some light on this problem in so far as they focus on measur
ing notions such as psychological illbeing (Book II of the Health Interview Survey – Belgium 2004, pp 204-209): “The psych
ological well-being assessed in the 2004 Belgian Health Survey is measured by means of an instrument (GHQ-12, General Health Questionnaire) that uses scores rang
...[+++]ing from 0 to 12. A higher score indicates a higher probability/severity of psychological ill-being.