Why has the incidence of schizophrenia in Danish psychiatric institutions decreased since 1970?

From The Danish Psychiatric Register five cohorts of all first-admitted patients to Danish psychiatric institutions from the years 1970, 1973, 1976, 1979, and 1980 have been followed, and trends in age-standardized rates of schizophrenia investigated. The first-admission rates have decreased in both sexes, significantly in males. In addition, the cumulated schizophrenia rates for the cohorts, including those of patients diagnosed as schizophrenics only at a later admission within periods of 2 and 5 years, decreased. This decrease is significant at 2 years of observation in both sexes and at 5 years in females. The decreasing first-admission rates might be explained partly by changes in diagnostic habits. The differential diagnoses of schizophrenia (paranoid states (ICD-8:297), paranoid reactive psychoses (298.3), unspecified psychoses (298.9 and 299), and borderline states (ICD-8 Danish version: 301.83] are increasingly used as first-admission diagnosis for patients later to be diagnosed as schizophrenic, possibly owing to a tendency to avoid the diagnosis of schizophrenia, when treatment of a patient is possible. A method of calculating the hospital incidence of schizophrenia approaching the real incidence better than the incidence of first-admission diagnoses is suggested.     

An independent analysis of the Danish Adoption Study of Schizophrenia. VI. The relationship between psychiatric disorders as defined by DSM-III in the relatives and adoptees

In this report, modified DSM-III criteria were applied to all the available interviews with adoptees from the greater Copenhagen sample of the Danish Adoption Study of Schizophrenia. In the adoptees, reasonable agreement was found between our DSM-III diagnoses and the original diagnoses using global DSM-II-based criteria by Kety et al for their categories of chronic and acute, but not borderline, schizophrenia. Comparing DSM-III-based diagnoses in adoptees and relatives, schizophrenia, schizotypal personality disorder, and paranoid personality disorder were all significantly more common in the biologic relatives of schizophrenic v screened control adoptees. These three diagnoses, which together form a tentative "schizophrenia spectrum," were also significantly concentrated in the biologic relatives of adoptees with schizoaffective disorder, mainly schizophrenic subtype, and schizotypal personality disorder, but not in biologic relatives of adoptees with schizophreniform disorder or atypical psychosis.     

The schizophrenia diagnosis in Denmark. A register-based investigation

Patients, Danish citizens only, admitted for the first time in 1972 to a Danish psychiatric institution were selected from the national psychiatric register. To be included, the probands had to have been diagnosed as schizophrenics at least once in the period from their first admission to 1 September 1983. The study comprised 370 males and 217 females with a total of 5,298 admissions. The probands' diagnostic pattern during the above period was investigated. More males (51.9%) than females (39.2%) (P less than 0.01) were diagnosed as schizophrenics during their first admission. The average period from a patient's first contact with an in-patient institution until schizophrenia was diagnosed for the first time was 2.2 years for females and 1.7 years for males (P less than 0.05). Personality disorders, reactive psychoses, and not classifiable psychoses were the most frequent diagnoses prior to the first schizophrenia diagnosis. The diagnostic stability of schizophrenia as main diagnosis, after its first application, was 73.6% for males among a total of 2,539 admissions and 71.2% for females among 1,141 admissions. There was greater correlation between the latest and former diagnoses than between the first and subsequent diagnoses. This is valid both when distinguishing between schizophrenia and non-schizophrenia and when focusing on schizophrenia subtypes. The results are discussed, particularly the problem concerning the selection of representative cohorts for schizophrenia research projects.     

Outcome studies on schizophrenic psychoses in Helsinki

This paper deals with the prognosis of schizophrenic psychoses in Helsinki in 1950-1955, 1960-1965, 1965-1970, 1970-1975, and 1975-1980. The first 4 cohorts each include a sample of 100 patients taken in 1950, 1960, 1965, and 1970. The patients were admitted for the first time to a psychiatric hospital because of schizophrenic and paranoid psychoses. The 1975 material includes all (n = 94) first admissions for schizophrenia, fulfilling the DSM-III criteria of schizophrenia or schizophreniform psychosis.     

Prodromal unfolding: the validation of the Schizotypic Syndrome Questionnaire model in a sample of first-episode schizophrenic patients

Aim: Validation of Van Kampen's Schizotypic Syndrome Questionnaire (SSQ) model of schizophrenic prodromal unfolding. The SSQ model comprises 12 negative, asocial and psychotic‐like symptoms that are hypothesized to determine each other in terms of cause and effect. Method: Use was made of the Interview for the Retrospective Assessment of the Onset of Schizophrenia (IRAOS)‐dependent retrospective data assembled in the Mannheim Age–Beginning–Course Study sample of first‐episode schizophrenic patients to measure the SSQ symptoms. Both the mean positions of the IRAOS‐assessed symptoms on a continuum representing the proportion of total time of pre‐psychotic disturbance and the outcome of a series of LISREL analyses conducted on the IRAOS‐dependent data were addressed. Results: Both kinds of data supported the validity of the SSQ model; however, this was after introducing some (relatively minor or demonstrable ineffective) changes in the model as the ‘translation’ of the SSQ symptoms by means of the IRAOS was not always easy, or proved even impossible in the case of one symptom. Conclusions: The conclusion seems warranted that the present investigation supports the validity of the SSQ model as a model of pre‐psychotic and prodromal unfolding in patients diagnosed as suffering from schizophrenia. From a theoretical perspective, arguments are presented to interpret the SSQ model as a model of the core or principal symptoms of schizophrenia, including their temporal unfolding.     

Evaluation of diagnostic procedures in Swedish patients with schizophrenia and related psychoses

We aimed to estimate the value of structured interviews, medical records and Swedish register diagnoses for assessing lifetime diagnosis of patients with schizophrenia. Psychiatric records and diagnostic interviews of 143 Swedish patients diagnosed by their treating physician with schizophrenia and related disorders were scrutinized. Based on record analysis only, or a combined record and interview analysis, DSM-IV diagnoses were obtained by the OPCRIT algorithm. Independent of the OPCRIT algorithm, a standard research DSM-IV diagnosis, based on both record and interview analysis, was given by the research psychiatrist. Concordance rates for the different psychosis diagnoses were calculated. DSM-IV diagnoses based on records only, showed a good to excellent agreement with diagnoses based on records and interviews. Swedish register diagnoses displayed generally poor agreement with the research diagnoses. Nevertheless, 94% of subjects sometimes registered with a diagnosis of schizophrenic psychoses (i.e. schizophrenia, schizoaffective psychosis or schizophreniform disorder) displayed a standard research DSM-IV diagnosis of these disorders. For patients in long-term treatment for schizophrenia in Sweden, psychiatric record reviews should be optimal, cost effective and sufficient for assessment of lifetime research diagnoses of schizophrenia. For these patients a research interview adds little new information. The results further indicate that a Swedish register diagnosis of schizophrenic psychoses has a high positive predictive power to a standard research DSM-IV diagnosis of the disorders. It is concluded that for future Swedish large-scale genetic studies focusing on a broad definition of schizophrenia, it would be sufficient to rely on the Swedish register diagnoses of schizophrenic psychosis.     

Comparison of psychiatric ICD-10 diagnoses in Denmark and Germany

A dataset of psychiatric ICD-10 diagnoses from the Danish case register concerning psychiatric hospitals was compared with a sample of psychiatric diagnoses from 27 psychiatric hospitals in Germany. The comparison shows a higher proportion of F1 diagnoses in the German dataset and a difference in the coding of alcohol dependence and harmful use. Some further differences in the groups F0-F6 are demonstrated and some of them are discussed. The most frequent diagnoses found in both datasets but in different sequence are alcohol dependence syndrome and paranoid schizophrenia and, in third place, adjustment disorder. Various aspects of the problem of rarely used diagnoses are discussed.     

Evaluation of diagnostic procedures in Swedish patients with schizophrenia and related psychoses

We aimed to estimate the value of structured interviews, medical records and Swedish register diagnoses for assessing lifetime diagnosis of patients with schizophrenia. Psychiatric records and diagnostic interviews of 143 Swedish patients diagnosed by their treating physician with schizophrenia and related disorders were scrutinized. Based on record analysis only, or a combined record and interview analysis, DSM-IV diagnoses were obtained by the OPCRIT algorithm. Independent of the OPCRIT algorithm, a standard research DSM-IV diagnosis, based on both record and interview analysis, was given by the research psychiatrist. Concordance rates for the different psychosis diagnoses were calculated. DSM-IV diagnoses based on records only, showed a good to excellent agreement with diagnoses based on records and interviews. Swedish register diagnoses displayed generally poor agreement with the research diagnoses. Nevertheless, 94% of subjects sometimes registered with a diagnosis of schizophrenic psychoses (i.e. schizophrenia, schizoaffective psychosis or schizophreniform disorder) displayed a standard research DSM-IV diagnosis of these disorders. For patients in long-term treatment for schizophrenia in Sweden, psychiatric record reviews should be optimal, cost effective and sufficient for assessment of lifetime research diagnoses of schizophrenia. For these patients a research interview adds little new information. The results further indicate that a Swedish register diagnosis of schizophrenic psychoses has a high positive predictive power to a standard research DSM-IV diagnosis of the disorders. It is concluded that for future Swedish large-scale genetic studies focusing on a broad definition of schizophrenia, it would be sufficient to rely on the Swedish register diagnoses of schizophrenic psychosis.     

Diagnostic shifts of functional psychoses in the transition from ICD-9 to ICD-10

In order to identify diagnostic changes caused by the transition from ICD-9 to ICD-10, in a sample of 218 first hospitalised patients from the years 1980 and 1981, ICD-9 diagnoses were compared with ICD-10 diagnoses. For this comparison, functional psychoses were classified into five main diagnostic groups. Results showed a decreased frequency of the diagnostic groups schizophrenia, schizoaffective psychoses, and paranoid psychoses and an increased frequency of the diagnostic groups acute psychoses and affective psychoses. With the exception of acute psychoses and schizoaffective psychoses, a high agreement between ICD-9 and ICD-10 diagnoses was found, and the Kappa value was 0.70. With regard to the homogeneity of psychopathological symptoms, ICD-10 diagnoses showed no improvement over ICD-9 diagnoses. Nevertheless, ICD-10 diagnoses have gained in predictive validity because schizophrenia was further narrowed to cases with a more unfavourable outcome.     

Classification of functional psychoses with special reference to follow-up studies

The classification of functional psychoses is still a controversial issue, as are also diagnoses in psychiatry. The predictive validity of the diagnosis is of crucial importance. Diagnostic systems are discussed. The author presents the Scandinavian concept of reactive psychoses, schizophreniform psychoses and schizophrenia, and demonstrates from his own material on paranoid psychoses the predictive value of these concepts, with a percentage recovery of 81, 61 and 23% after long-term follow-up. The concepts are discussed in relation to ICD-9 and DSM-III. The concepts of paranoid disorders, affective disorders and borderline conditions are mentioned. The paper also introduces other papers to be presented in this volume.     

Finnish adoptive family study: sample selection and adoptee DSM-III-R diagnoses

OBJECTIVE: To evaluate the genetic contribution to schizophrenia using an adoption design that disentangles genetic and environmental factors. METHOD: Finnish hospital diagnoses of schizophrenic/paranoid psychosis in a nationwide sample of adopting-away women are compared with DSM-III-R research diagnoses for these mothers. DSM-III-R diagnoses of their index offspring are blindly compared with adopted-away offspring of epidemiologically unscreened control mothers. RESULTS: Primary sampling diagnoses of index mothers were confirmed using DSM-III-R criteria. Lifetime prevalence of typical schizophrenia in 164 index adoptees was 6.7% (age-corrected morbid risk 8.1%), significantly different from 2.0% prevalence (2.3% age-corrected morbid risk) in 197 control adoptees. When adoptees with diagnoses of schizoaffective disorder, schizophreniform disorder, schizotypal disorder and affective psychoses were added, the contrast between the index and control adoptees increased. CONCLUSION: The genetic liability to 'typical' DSM-III-R schizophrenia is decisively confirmed. Additionally, the liability also extends to a broad spectrum of other psychotic and non-psychotic disorders.     

Admission pattern and diagnostic stability among unipolar and bipolar manic-depressive patients

The instability of the diagnoses in a psychiatric register causes practical problems when groups of probands with specific diagnoses are selected for further studies. A cohort of 3,062 first admissions with at least one manic-depressive admission was followed for 5-7 years. 623 had at least one admission for mania and were considered bipolar. The percentage of patients who changed their diagnoses was highest at first readmission; at each later readmission about 10% of the bipolars and 25% of the unipolars changed from manic-depressive psychosis and a similar number changed from other diagnoses to manic-depressive psychosis. Compared with the diagnostic distribution of all register cases, reactive psychoses were more frequent than expected as former diagnoses and schizophrenia as later diagnosis. Neuroses and character deviations were frequent alternative diagnoses among unipolars, not among bipolars. The consequences of different selection criteria for the composition of proband groups are discussed.     

PROGNOSIS OF PARANOID STATES IN RELATION TO THE CLINICAL FEATURES

Scandinavian psychiatrists acknowledge endogenous psychoses which are neither schizophrenic nor manic-depressive, i.e., above all the “reactive psychoses” and the “schizophreniform psychoses”, both of which differ from schizophrenia in their features as well as in their good prognoses. These Scandinavian diagnoses bear relationships to psychoses, which I separate from schizophrenia. In the present paper, paranoid states are discussed with regard to their clinical pictures and their good prognoses. Among these are the “cycloid psychoses”. Patients suffering from these diseases recover from every phase, though most of the German psychiatrists consider them schizophrenic. Among the cycloid psychoses, the “anxiety happiness psychosis” shows ideas of reference on the one hand and ecstatic ideas on the other. In “inhibited confusion psychosis”, the patients are suffering from ideas of reference and ideas of significance; in “excited confusion psychosis”, from misidentifications of persons. The other symptoms which occur - anxiety, happiness, stupor, incoherent pressure of speech - confirm the cycloid psychoses and disprove schizophrenias. Besides the already mentioned psychoses, there is a monopolar psychosis, “suspicious depression”, in which ideas of reference and ideas of guilt mix. It is extremely important, not only for theoretical but also practical reasons, to separate from schizophrenia paranoid states which terminate in complete recovery from every phase.     

Beginning schizophrenia observed by significant others

As a part of the ABC Schizophrenia Study, a large-scale investigation of the influences of age and gender on the onset and course of schizophrenia, this study compared retrospective reports about emerging symptomatology during the early course of schizophrenia given by patients and their significant others in a representative lirst admission sample. The Interview for the Retrospective Assessment of the Onset of Schizophrenia (IRAOS), a comprehensive interview assessing early signs and symptoms, revealed that, in most cases, patients as well as informants perceived negative, depressive, and unspecific symptoms as early signs of the disorder. Pairwise agreement about the presence of certain symptoms was good for a limited number of signs, e. g., substance abuse, suieidal behavior, parental and marital role deficits, and paranoid delusions. These items mainly concern abnormal behaviors that can be observed easily. In contrast, there was little agreement between reports about perceptual and formal thought disorder, i.e., subjective internal phenomena. The results supported a continuity model for the observability of symptoms in schizophrenia.     

Reactive psychoses and schizophrenia with good prognosis.

Cross-national studies have indicated that American psychiatrists diagnose schizophrenia more often than others. Clinical, genetic, and follow-up studies suggest that many patients diagnosed as having acute schizophrenia might be more appropriately diagnosed as having affective disorder. Forty probands diagnosed in Aarhus, Denmark, as having reactive psychoses are compared with 28 probands diagnosed in St Louis as having schizophrenia with good prognosis. Clinical differences largely reflect diagnostic criteria, with the patients from the St Louis group frequently having diagnosable affective disorder. A smaller proportion, 39% of the patients from St Louis, could be considered for the diagnosis of reactive psychosis. This is additional evidence supporting the use of the diagnostic category, reactive psychoses. Patients ordinarily given the diagnoses acute schizophrenic episode and/or schizo-affective schizophrenia may be more appropriately diagnosed as having (1) affective disorder and (2) reactive psychoses.     

Depressive states occurring during the neuroleptic treatment of schizophrenia

Depressive states are often observed during the hospitalizations of acutely schizophrenic patients. But only a few studies have examined the frequency and course pattern of these depressions. In our investigation of 81 patients suffering from schizophrenic or paranoid psychoses and undergoing neuroleptic treatment, we found that the frequency and intensity of depression decreased from admission to discharge. On admission, 63 percent of patients showed a marked depressive apathetic syndrome, as compared to only 23 percent on discharge. Patients' self-rating data from the Actual Mood Scale (filled out every other day) showed that only a small proportion of the patients developed a depression during hospitalization without having also been depressed on admission. An analysis of psychiatrists' admission and discharge ratings produced similar results. Our findings suggest tht neuroleptics are unlikely to be the major cause of depressions in patients suffering from acute schizophrenic or paranoid psychoses.     

The genetics of delusional psychoses

In a genetic study of the first-degree relatives of 77 patients with delusional (paranoid) psychoses, the morbidity risks for schizophrenia, affective disorders, and atypical psychoses were evaluated using ICD-9 criteria. The prevalence of schizophrenia was 3.10 percent (4.12 percent with age correction to 40 years and 4.94 percent with age correction to age 60), which is higher than in investigations of paranoid psychoses, but lower than in studies of paranoid schizophrenia. The prevalence figure for affective disorders (age-corrected 3.04 percent for unipolar plus bipolar patients) is also intermediate to those for relatives of paranoid schizophrenics and paranoid psychotics. When the 77 index delusional patients were subdivided into axial syndromes (endogenomorphic-schizophrenic, endogenomorphic-cyclothymic, and organomorphic axial syndromes), two very homogeneous subgroups emerged. The endogenomorphic-schizophrenic subgroup showed high rates of schizophrenic secondary cases, whereas the endogenomorphic-cyclothymic subgroup showed high rates of affectively disordered secondary cases. The third organomorphic subgroup showed a high prevalence of atypical psychoses among first-degree relatives. Thirty-seven of the 77 index patients could not be assigned to any axial syndrome; their first-degree relatives had an increased prevalence of schizophrenia, but affective disorders were no more frequent than in the normal population. These data suggest that the heterogeneous group of paranoid psychoses can be meaningfully subdivided by use of axial syndromes which are viewed as representing "basic" disturbances underlying delusional symptomatology.     

Long-term follow-up of paranoid psychoses

Approximately 200 out of 301 first-admitted hospitalized patients with paranoid psychoses earlier studied by Retterst?l are still alive. These subjects are at present being interviewed semistructurally by the author, making a total follow-up period of 22-37 years after index admission. Before the interviews, diagnoses at discharge and at previous follow-ups based upon the records are established. Different diagnostic procedures are used. Preliminary results from the first 125 interviews indicate a small change to the worse as to psychopathology during the last 20 years. Outcome in DSM-III schizophreniform disorder, RDC schizoaffective disorders, Kendler's delusional disorders and ICD-9 reactive psychoses differs distinctly from the less favorable outcome in DSM-III schizophrenia.     

首发精神分裂症患者血浆白细胞介素6、免疫球蛋白G变化研究

目的：研究首发偏执型精神分裂症患者血浆中自细胞介素6(IL—6)、免疫球蛋白G(IgG)的变化。方法：对首发偏执型精神分裂症患者30例，单独应用氯氮平治疗；20例健康志愿者为对照组。采用酶联免疫吸附法测定血浆中IL—6的浓度，应用速率散射比浊法检测IgG的血浆浓度，并进行组间比较。结果：精神分裂症组在治疗前血浆IL—6、IgG的水平显著增高，治疗6周症状缓解后仍显著增高；症状基本缓解后与治疗前比较差异无显著性。结论：精神分裂症患者存在免疫功能紊乱。     

The significance of genetic factors in the etiology of schizophrenia: Results from the national study of adoptees in Denmark

The prevalence of schizophrenic illness in the biological and adoptive relatives of schizophrenic adoptees has been examined for a total sample of adoptees in Denmark. The total sample was studied in two stages, beginning with the Copenhagen sample of adoptions granted by the courts in the city and county of Copenhagen, the results of which have been reported previously. The adoptions granted by the courts in the remainder of Denmark comprised the Provincial sample the preliminary results of which appear to confirm those obtained earlier. Chronic schizophrenia and milder syndromes described as latent, borderline, or uncertain schizophrenia were found in both samples to concentrate significantly in the biological relatives of schizophrenic adoptees as compared to their controls, but not in their adoptive relatives. These milder and marginal syndromes resembling schizophrenia occurring in the families of schizophrenic patients confirm the observations of Bleuler and others who succeeded him. Their presence in the biological families of schizophrenic adoptees indicates not only their familial but also genetic relationship to schizophrenia.