Reasons for modification

The development and printing of SCAN-1/PSE-10.1 is mentioned briefly at the end of Chapter 8. The following account of the changes incorporated during the revision for SCAN-2.0 and then SCAN- 2.1/PSE-10.2 is presented both for the record and for the benefit of those familiar with SCAN-1.

Preliminary experience with sections first incorporated in SCAN-1 highlighted the need for a number of further changes. Section 2 (Physical Health, Somatoform and Dissociative Disorder) needed to cover more accurately and clearly the classification rules of DSM-IIIR and ICD-10. Similarly, users of Sections 11 and 12 (Alcohol and Psychoactive Substances) had encountered difficulties and some had found the length of the sections unnecessarily tedious. Users of Section 20 (Cognitive Impairment and/or Decline) also generated detailed suggestions. While it was recognised that Section 20 was designed as a screening tool, desire for greater diagnostic information was also expressed. SCAN and PSE users who were not familiar with the concepts of Acute Stress Reaction and Adjustment Disorder (Section 1) also called for clarification.

The introduction in SCAN-1, in rating scale I, of the ‘6’ rating ('symptom present but physical illness makes rating difficult) and ‘7’ (trait rating) was also criticised. Trainers and interviewers expressed a concern that it could be difficult to know whether to rate a symptom present (2 or 3), a trait (7), or a physical cause (6). Moreover, a rating of 6 did not allow severity to be included. A group in Baltimore (Anthony et al., 1985) had begun to develop a clinical assessment method based on an extension of PSE-9, in which the examiner was required to record separately a clinical judgement as to whether a symptom was due to an external substance or to physical ill health. The view was that the record of such attributions should be separate from rating scale I. This matter is discussed later.

However, the most compelling reasons for producing first SCAN-2.0 and then SCAN-2.1 were last minute changes in the final published version of the ICD-10 Diagnostic Criteria for Research (DCR; WHO, 1993), and some changes needed for extra coverage of a few areas of DSM-III-R, and the introduction of DSM IV in May 1994 (APA, 1994).