In defence of international classification

The chapter on mental disease in the eighth revision of the International Classification of Diseases (ICD-8) was internationally accepted in about 1970. The main reason for the previous reluctance to accept international standards had been the prevailing national discrepancies in diagnostic practice. In Norway and Denmark, where the Kraepelinian nosology was traditional, a need was felt for a third category of functional psychoses ('reactive' or 'psychogenic') in addition to schizophrenia and manic-depressive disorder. More than 42% of first admissions to Norwegian psychiatric hospitals were given this diagnosis in 1965, and in Denmark the comparable figure for first admissions in 1965-6 was 39%. In France intermediate categories of functional psychoses were introduced in the nineteenth century. In Sweden, the USA, the USSR and the UK, however, psychiatrists felt no need for such categories, since they employed either an extremely wide concept of schizophrenia (USA, USSR) or of affective disorder (UK), while in Sweden more than 60% of first admissions in 1962-4 were classified as 'non-psychotic'. In ICD-8 the World Health Organization proposed a change in diagnostic practice by reserving the 3-digit category 298 for the 'intermediate' (other) psychoses, and by introducing three new subgroups of schizophrenia which, by definition, had a favourable outcome (295-4, 295-5, 295-7). It is therefore of some interest to determine whether there is now a greater uniformity in diagnostic practice. Information on first admissions to psychiatric hospitals by diagnosis is available from several countries: Denmark, Norway, England and Wales, France, Poland, Australia (the province of Victoria), and the USA. The proportion of 'intermediate' psychoses ranged from 8-3% (Australia), 11-8% (USA) to 36-8% in Denmark, where admissions classified as schizophrenia amounted to 7-4%, as compared with 11-5% in England and Wales and 46-6% in the USA. Affective disorder was diagnosed in only 6-3% of cases in Norway, compared with 37-1% in the USA and 42-5% in England and Wales, where 'depressions not elsewhere classified' were included in this category. The proportion of non-psychotic admissions ranged from less than 5% (USA) to more than 50% (Norway). The discrepancy in diagnostic distribution is therefore more or less the same as before the introduction of the ICD-8. In countries with a wide concept of schizophrenia the figures for this diagnosis were unchanged (USA); in Norway, with its very narrow concept of the disorder, there was an even further reduction in admissions classified as schizophrenia. The three new subgroups of schizophrenia were used in only 1-2% of cases. In England and Wales the proportion of affective disorder, including ' depressions not elsewhere classified', has remained high and did not change in 1970-7. In Norway, furthermore, there has been not only a flight from the two Kraepelinian disease entities, now diagnosed in only 10% of admissions, but also from the use of the term 'psychosis'; for there is now a predominance of non-psychotic admissions. This change might have resulted from a failure to have eliminated the social stigma attached to the notion of psychosis. Psychiatrists prefer a diagnosis which implies a favourable outcome, and non-psychotic depression (300-4) has become the most common diagnosis (Saugstad & 0degard, 1980, 1983). This preference for depression as the least stigmatizing of mental disorders is also characteristic of England and Wales, where nearly two-thirds of first admissions are classified as non-psychotic depressions or 'depressions not elsewhere classified'. This trend goes back to Aubrey Lewis' influential paper of 1934, establishing the concept of affective disorder which included those depressive psychoses classified as 'reactive or psychogenic' in Norway and Denmark. This category also includes cases which in the USA would have been labelled as schizophrenic or schizoaffective, as is evident from Kan tor & Glassman's (1977) re-examination of Lewis' 61 original case reports. The persistent predominance of schizophrenia (46-6%) in the USA