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| Diagnostic Systems and Prognostic Pessimism |
Diagnostic Systems and Prognostic Pessimism
For the first half of the twentieth century, there was no universal or even widespread definition of schizophrenia. In the United States, the strong psychoanalytic tradition led to a leaning towards Bleuler’s broader definition, while in the United Kingdom, Schneider’s first-rank symptoms were dominant, and in Europe diagnosis was largely based on Kraepelin’s prognostic approach (Clare, 1980). Different countries, even different schools within a country, had widely differing conceptualizations of schizophrenia (Leff, 1988). The first classification systems for mental disorders were published in the mid-twentieth century. The World Health Organization (WHO) included mental disorders in the sixth edition of the International Classification of Diseases, Injuries and Causes of Death (ICD-6; WHO, 1948) and the American Psychiatric Association (APA) published the first edition of the Diagnostic and Statistical Manual in 1952 (DSM I; APA, 1952). However, diagnosis of schizophrenia was much more frequent in the United States than it was in the United Kingdom or Europe. Two major research programmes highlighted this problem. The United States–United Kingdom Diagnostic Project (Cooper et al., 1972) found that there were almost twice as many people admitted to hospital with a diagnosis of schizophrenia in the USA than in the UK. In addition, when UK psychiatrists diagnosed the USA schizophrenia patients, only approximately 50% were given the same diagnosis (Cooper et al., 1972). The WHO then conducted the International Pilot Study of Schizophrenia (IPSS), a transcultural research project that compared diagnostic practices across nine countries (WHO, 1973). Again it was found that many patients diagnosed with schizophrenia in the United States would have been given a diagnosis of neurosis in other centres.
Following from these studies, the DSM-III (APA, 1980) represented a major change in official diagnostic procedures, advocating the use of operationally defined phenomenological criteria based on Schneider’s (1957, cited in Leff, 1988) first-rank symptoms, and specifying a minimum duration of illness of six months (Leff, 1988).
As a consequence, the DSM-III diagnostic criteria were much narrower than those of its predecessors, or even the ICD criteria (Leff, 1988), which still retains simple schizophrenia, a diagnosis not requiring any psychotic symptoms (Bertelsen, 2002).
The DSM-III took an atheoretical approach to classification which avoided descriptions based on an assumed aetiology, although a chronic course was still emphasized (Carpenter and Buchanan, 1994). It was not until work began on the tenth edition of the ICD (ICD-10; WHO, 1992) that international efforts were made to coordinate diagnostic criteria, mainly for the purposes of research. As a result, diagnostic criteria for schizophrenia in the fourth edition of the DSM (DSM-IV; APA, 1994) and the ICD-10 are much more closely aligned than previous systems.
For the first half of the twentieth century, there was no universal or even widespread definition of schizophrenia. In the United States, the strong psychoanalytic tradition led to a leaning towards Bleuler’s broader definition, while in the United Kingdom, Schneider’s first-rank symptoms were dominant, and in Europe diagnosis was largely based on Kraepelin’s prognostic approach (Clare, 1980). Different countries, even different schools within a country, had widely differing conceptualizations of schizophrenia (Leff, 1988). The first classification systems for mental disorders were published in the mid-twentieth century. The World Health Organization (WHO) included mental disorders in the sixth edition of the International Classification of Diseases, Injuries and Causes of Death (ICD-6; WHO, 1948) and the American Psychiatric Association (APA) published the first edition of the Diagnostic and Statistical Manual in 1952 (DSM I; APA, 1952). However, diagnosis of schizophrenia was much more frequent in the United States than it was in the United Kingdom or Europe. Two major research programmes highlighted this problem. The United States–United Kingdom Diagnostic Project (Cooper et al., 1972) found that there were almost twice as many people admitted to hospital with a diagnosis of schizophrenia in the USA than in the UK. In addition, when UK psychiatrists diagnosed the USA schizophrenia patients, only approximately 50% were given the same diagnosis (Cooper et al., 1972). The WHO then conducted the International Pilot Study of Schizophrenia (IPSS), a transcultural research project that compared diagnostic practices across nine countries (WHO, 1973). Again it was found that many patients diagnosed with schizophrenia in the United States would have been given a diagnosis of neurosis in other centres.
Following from these studies, the DSM-III (APA, 1980) represented a major change in official diagnostic procedures, advocating the use of operationally defined phenomenological criteria based on Schneider’s (1957, cited in Leff, 1988) first-rank symptoms, and specifying a minimum duration of illness of six months (Leff, 1988).
As a consequence, the DSM-III diagnostic criteria were much narrower than those of its predecessors, or even the ICD criteria (Leff, 1988), which still retains simple schizophrenia, a diagnosis not requiring any psychotic symptoms (Bertelsen, 2002).
The DSM-III took an atheoretical approach to classification which avoided descriptions based on an assumed aetiology, although a chronic course was still emphasized (Carpenter and Buchanan, 1994). It was not until work began on the tenth edition of the ICD (ICD-10; WHO, 1992) that international efforts were made to coordinate diagnostic criteria, mainly for the purposes of research. As a result, diagnostic criteria for schizophrenia in the fourth edition of the DSM (DSM-IV; APA, 1994) and the ICD-10 are much more closely aligned than previous systems.
The ICD-10 continues to give diagnostic importance to Schneider’s first-rank symptoms, and, although the DSM-IV states that no single symptom is pathognomonic for schizophrenia, the presence of ‘bizarre’ delusions, or auditory hallucinations consisting of a voice giving a running commentary on the person’s behaviour, or two voices conversing, are sufficient to meet the psychosis criterion for schizophrenia.
Kraepelin’s belief that all mental illnesses arise from biological causes has tended to dominate psychiatric classification systems. It was not until the DSM-IV that any remaining distinction between organic and psychological disorders was eliminated (Barlow and Durand, 1995). In practice, Bleuler’s broad definitions of ‘simple’ and ‘latent’ schizophrenia became coupled to Kraepelin’s organic formulation, giving a wide range of disagreeable behaviour the weight of a medical diagnosis (Wing, 999). Thus the pessimistic prognosis inherent in Kraepelin’s early formulation became incorporated into the expectations of those professionals who were using Bleuler’s more inclusive definition, with the result that people who were diagnosed with schizophrenia on even the most loosely-defined criteria were not expected to recover.
Kraepelin’s belief that all mental illnesses arise from biological causes has tended to dominate psychiatric classification systems. It was not until the DSM-IV that any remaining distinction between organic and psychological disorders was eliminated (Barlow and Durand, 1995). In practice, Bleuler’s broad definitions of ‘simple’ and ‘latent’ schizophrenia became coupled to Kraepelin’s organic formulation, giving a wide range of disagreeable behaviour the weight of a medical diagnosis (Wing, 999). Thus the pessimistic prognosis inherent in Kraepelin’s early formulation became incorporated into the expectations of those professionals who were using Bleuler’s more inclusive definition, with the result that people who were diagnosed with schizophrenia on even the most loosely-defined criteria were not expected to recover.
