"Measure levels of psychological distress or depression"
At various ages from teenager to adulthood, BCS70 cohort members have completed the Malaise Inventory (Rutter et al., 1970) - a set of self-completion questions which combine to measure levels of psychological distress, or depression. The 24 ‘yes-no’ items of the inventory cover emotional disturbance and associated physical symptoms. When administered in its standard format, scores range from 0 to 24.
The Malaise Inventory was itself developed from the Cornell Medical Index Health Questionnaire (CMI) which is comprised of 195 self-completion questions (Brodman et al., 1949, 1952). Fourteen of the 24 questions are taken directly from the CMI (Rutter et al., 1970). Individuals responding ‘yes’ to eight or more of the 24 items are considered to be at risk of depression (Rodgers et al., 1999).
The internal consistency of the scale has been shown to be acceptable and validity of the inventory shown to hold in different socio-economic groups (Rodgers et al., 1999).
The scale has been used in both general population studies (McGee, Williams and Silva, 1986; Rutter and Madge, 1976; Rodgers et al., 1999) and in investigations of high-risk groups (Grant, Nolan and Ellis, 1990).
Rutter himself affirms that 'the inventory differentiates moderately well between individuals with and without psychiatric disorder' (Rutter et al., 1970, p160).
The individual questions and the ages they have been asked in the two cohorts are detailed in the next section.