METHODOLOGY
Selection of Patients
The study was confined to hospital patients. They formed a consecutive series of primarily depressed or anxious inpatients (N = 136), day patients (N = 22), and outpatients (N = 22) who were interviewed in the psychiatric units serving the city of Newcastle-Upon-Tyne and surrounding districts. The inpatient units were sampled first, then the consecutive outpatients and day hospital patients. Limitation of time and slow accretion of these latter groups accounted for the reason why the outpatient and day patient numbers were much less than inpatients. The more usual method of case selection by applying diagnostic criteria was deliberately avoided. Instead, patients were selected on the basis of a sustained mood disturbance that was not considered secondary to any other psychiatric disorder. Specific criteria were used to exclude patients with schizophrenia, coarse brain disease, obsessive-compulsive neurosis, anorexia nervosa, epilepsy, alcoholism, and mental subnormality. Patients with transient mood disturbance of
less than 72 hours and those aged below 15 or above 65 years were excluded. The series comprised 180 patients, 67 males and 113 females, mean age 43.3 years (S.D. 12.53), whose demographic characteristics are shown in Table 2.
Selection of Clinical Items
A frequency analysis of all the items included in various studies of the affective disorders until 1975 was carried out. This included all studies in literature purporting to both describe and discriminate various subtypes of depression and
anxiety. The most frequently occurring 170 items were chosen. These included mainly clinical state items, but biographical and personality features were also included. A structured interview schedule with a glossary of definitions was then constructed. This information was supplemented by a detailed descriptive account of the illness, and a history of the patients’ previous development and premorbid personality. The structured interview was essentially clinical in character, and the responsibility for judging the presence, absence, or grade of any item was left to the investigator. The items selected included almost the whole range of symptomatology found in depressive illnesses and anxiety states. An effort was made to standardize the definition of items with the PSE (13), yet there remained distinct differences, as a quantitative rating on a 4-point scale per item (initially) was incorporated into the structured interview. When computed, the distributions of all items were normalized to avoid U- and J-shaped distributions. Kappa (3), a coefficient of agreement, was high for all items.